Control method of energy storage railway power regulator and terminal equipment

文档序号：1877803 发布日期：2021-11-23 浏览：22次中文

阅读说明：本技术 储能铁路功率调节器控制方法及终端设备 (Control method of energy storage railway power regulator and terminal equipment ) 是由戎士洋周文胡雪凯曾四鸣耿博良肖国春于 2021-07-08 设计创作，主要内容包括：本发明适用于电能质量与储能控制技术领域,提供了一种储能铁路功率调节器控制方法及终端设备,应用于储能半桥变换器单元由半桥变换器和储能单元并联构成的储能铁路功率调节器,该方法包括：对储能铁路功率调节器对应的各相负载电流进行电流补偿,得到第一调制信号；基于储能铁路功率调节器的各相补偿电流、每个半桥变换器单元和每个储能半桥变换器单元的电容电压进行环流控制,得到第二调制信号；基于电容电压及每个储能半桥变换器单元的储能电池实际电流和储能电池实际荷电状态进行双环控制,得到第三调制信号；根据第一至第三调制信号,控制储能铁路功率调节器。本发明方法能够实现能量的自动补偿、控制指令少且控制指令间耦合性较低。(The invention is suitable for the technical field of electric energy quality and energy storage control, and provides a control method and terminal equipment of an energy storage railway power regulator, which are applied to the energy storage railway power regulator formed by connecting an energy storage half-bridge converter unit in parallel with an energy storage unit, wherein the method comprises the following steps: carrying out current compensation on each phase of load current corresponding to the energy storage railway power regulator to obtain a first modulation signal; performing circulation control on the basis of compensation currents of all phases of the energy storage railway power regulator and capacitor voltages of each half-bridge converter unit and each energy storage half-bridge converter unit to obtain a second modulation signal; performing double-loop control on the basis of the capacitor voltage, the actual current of the energy storage battery of each energy storage half-bridge converter unit and the actual charge state of the energy storage battery to obtain a third modulation signal; and controlling the energy storage railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal. The method can realize automatic compensation of energy, and has the advantages of less control instructions and lower coupling among the control instructions.)

1. A control method of an energy storage railway power regulator is characterized in that the control method is applied to the energy storage railway power regulator formed by connecting an energy storage half-bridge converter unit in parallel with a half-bridge converter, a direct current voltage stabilizing capacitor and an energy storage unit, and comprises the following steps:

carrying out current compensation processing on each phase of load current of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and calculating to obtain a first modulation signal controlled by the alternating current; performing circulation control processing based on the obtained compensation current of each phase of the energy storage railway power regulator and the capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit, and calculating to obtain a second modulation signal for circulation control; performing double-loop control on the basis of the capacitor voltage and the acquired actual current and the actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and calculating to obtain a third modulation signal controlled by the unit; and controlling a half-bridge converter unit and an energy storage half-bridge converter unit in the energy storage railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal.

2. The energy-storage railway power regulator control method according to claim 1, wherein the energy-storage railway power regulator comprises a first bridge arm module, a second bridge arm module and a third bridge arm module which are connected in parallel, each bridge arm module comprises an upper bridge arm submodule and a lower bridge arm submodule which are connected in series and have the same connection structure, each bridge arm submodule comprises at least two converter units which are connected in series and have the same number, at least two converter units of at least one bridge arm submodule in each bridge arm submodule comprise both a half-bridge converter unit and an energy-storage half-bridge converter unit, each energy-storage half-bridge converter unit comprises an energy-storage unit, a half-bridge converter and a direct-current voltage-stabilizing capacitor which are connected in parallel, and all energy-storage units in the energy-storage railway power regulator form an energy-storage system.

3. The energy-storing railway power regulator control method of claim 2, wherein the capacitor voltage comprises a first capacitor voltage of each half-bridge converter cell in the energy-storing railway power regulator and a second capacitor voltage of each energy-storing half-bridge converter cell in the energy-storing railway power regulator;

and performing double-loop control based on the capacitor voltage and the obtained actual current and the actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and calculating to obtain a third modulation signal controlled by the unit, wherein the method comprises the following steps of:

calculating to obtain the average bridge arm energy storage battery current of each bridge arm submodule according to the actual current of the energy storage battery;

calculating to obtain the average voltage of the capacitor of each bridge arm submodule according to the first capacitor voltage and the second capacitor voltage;

adjusting according to the first capacitor voltage, the average energy storage battery current of the bridge arm and the obtained bridge arm current of each bridge arm submodule, and calculating to obtain a first sub-modulation signal of each half-bridge converter unit;

calculating to obtain the average charge state of the bridge arm energy storage battery of each bridge arm submodule according to the actual charge state of the energy storage battery;

adjusting according to the second capacitor voltage, the actual current of the energy storage battery, the average voltage of the capacitor, the average current of the energy storage battery of the bridge arm, the actual state of charge of the energy storage battery, the average state of charge of the energy storage battery of the bridge arm and the current of the bridge arm, and calculating to obtain a second sub-modulation signal of each energy storage half-bridge converter unit;

adjusting a voltage outer ring and a current inner ring according to the obtained capacitance reference voltage of the energy storage railway power regulator, the second capacitance voltage and the actual current of the energy storage battery, and calculating to obtain a third sub-modulation signal of each energy storage half-bridge converter unit;

and taking the first sub-modulation signal, the second sub-modulation signal and the third sub-modulation signal as a third modulation signal for unit control.

4. The energy storage railway power regulator control method according to claim 3, wherein the calculating a second sub-modulation signal of each energy storage half-bridge converter unit according to the regulation of the second capacitor voltage, the actual energy storage battery current, the average capacitor voltage, the average bridge arm energy storage battery current, the actual energy storage battery state of charge, the average bridge arm energy storage battery state of charge and the bridge arm current comprises:

calculating a second difference value between the actual current of the energy storage battery and the average current of the energy storage battery of the bridge arm, and performing proportion adjustment on the second difference value to obtain a battery current feedforward control signal of each energy storage half-bridge converter unit;

calculating a third difference value between the average charge state of the bridge arm energy storage battery and the actual charge state of the energy storage battery, and performing proportional-integral adjustment on the third difference value to obtain a charge state balance adjustment signal of each energy storage half-bridge converter unit;

calculating the sum of the initial modulation signal, the battery current feedforward control signal and the state of charge balance adjustment signal to obtain an initial second sub-modulation signal of each energy storage half-bridge converter unit;

and determining the positive and negative of the initial second sub-modulation signal according to the positive and negative of the bridge arm current, and obtaining a second sub-modulation signal of each energy storage half-bridge converter unit according to the initial second sub-modulation signal after the positive and negative are determined.

5. The method for controlling the energy storage railway power regulator according to claim 3, wherein the step of performing voltage outer loop and current inner loop regulation according to the acquired capacitor reference voltage of the energy storage railway power regulator, the acquired second capacitor voltage and the acquired actual current of the energy storage battery to calculate a third sub-modulation signal of each energy storage half-bridge converter unit comprises:

taking the inverse number of the reference value of the discharge current of the energy storage battery to obtain the reference value of the charge current of the energy storage battery of each energy storage half-bridge converter unit;

and calculating a fifth difference value between the reference value of the charging current of the energy storage battery and the actual current of the energy storage battery, and performing proportional-integral adjustment on the fifth difference value to obtain a third sub-modulation signal of each energy storage half-bridge converter unit.

6. The method for controlling an energy storage railway power regulator according to any one of claims 3 to 5, wherein the step of performing current compensation processing on the load current of each phase of the electric locomotive load corresponding to the obtained energy storage railway power regulator to calculate the first modulation signal for controlling the alternating current comprises the following steps:

acquiring a first equivalent current and a second equivalent current; the first equivalent current is equivalent current of active power output to the alpha phase by the energy storage system through the energy storage railway power regulator at the alternating current side of the energy storage railway power regulator, and the second equivalent current is equivalent current of active power output to the beta phase by the energy storage system through the energy storage railway power regulator at the alternating current side of the energy storage railway power regulator;

carrying out current compensation processing according to the load current of each phase, the first equivalent current and the second equivalent current, and calculating to obtain a compensation current d-axis component;

carrying out dq conversion on the load current of each phase, and calculating to obtain a q-axis component of the load current;

multiplying the q-axis component of the load current by-1 to obtain a q-axis component of the compensation current;

carrying out dq inverse transformation according to the d-axis component and the q-axis component of the compensation current, and calculating to obtain a reference instruction of the compensation current of each phase;

and calculating to obtain a first modulation signal controlled by the alternating current according to the compensation current of each phase and the compensation current reference instruction of each phase.

7. An energy storage railway power regulator control method according to any one of claims 3 to 5, wherein the calculating of the second modulation signal for loop control based on the obtained compensation current of each phase of the energy storage railway power regulator, the obtained capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit in the energy storage railway power regulator, comprises:

decomposing the compensation current of each phase, and calculating to obtain a circulation reference value of each phase according to a decomposition result;

calculating to obtain a per unit value of the total first capacitance energy of all the converter units in each upper bridge arm sub-module and a per unit value of the total second capacitance energy of all the converter units in each lower bridge arm sub-module according to the first capacitance voltage and the second capacitance voltage;

calculating a per unit value of the total energy reference value of the first capacitor of each bridge arm module according to the obtained capacitor reference voltage;

performing proportional integral adjustment according to the difference between the sum of the per-unit value of the total energy of the first capacitor and the per-unit value of the total energy of the second capacitor and the per-unit value of the reference value of the total energy of the first capacitor, and calculating to obtain an initial phase balance control power reference value of each phase;

according to the actual current of the energy storage battery and the actual state of charge of the energy storage battery, performing feed-forward regulation and state of charge balance regulation on the initial phase balance control power reference value, and calculating to obtain a phase balance control signal of each phase;

performing proportional integral adjustment according to the difference between the per-unit value of the total energy of the first capacitor and the per-unit value of the total energy of the second capacitor, and calculating to obtain an initial bridge arm balance control power reference value of each phase;

according to the actual current and the actual state of charge of the energy storage battery, performing feed-forward regulation and state of charge balance regulation on the initial bridge arm balance control power reference value, and calculating to obtain bridge arm balance control signals of each phase;

and regulating the acquired actual circulation of each phase of the energy storage railway power regulator, the circulation reference value of each phase, the phase balance control signal of each phase and the bridge arm balance control signal of each phase through a proportional-integral resonance regulator, and calculating to obtain a second modulation signal for circulation control.

8. The method for controlling the power conditioner of the energy storage railway according to claim 7, wherein the step of performing feed-forward regulation and state-of-charge balance regulation on the initial phase balance control power reference value according to the actual current of the energy storage battery and the actual state-of-charge of the energy storage battery to obtain the phase balance control signal of each phase by calculation comprises the following steps:

carrying out proportion adjustment according to the difference between the total current of the third energy storage battery and the average current of the energy storage battery, and calculating to obtain a first feedforward adjustment quantity of each phase;

calculating to obtain the average charge state of the energy storage batteries of all energy storage half-bridge converter units in the energy storage railway power regulator and the average charge state of the phase energy storage battery corresponding to each bridge arm module according to the actual charge state of the energy storage batteries;

performing proportional integral adjustment according to the difference between the average state of charge of the energy storage battery and the average state of charge of the phase energy storage battery, and calculating to obtain a first state of charge balance adjustment quantity of each phase;

calculating the sum of the initial phase equilibrium control power reference value, the first feedforward adjustment quantity and the first state of charge equilibrium adjustment quantity to obtain a phase equilibrium control power reference value of each phase;

and calculating to obtain the phase equalization control signal of each phase according to the phase equalization control power reference value.

9. The energy-storing railway power regulator control method of claim 7, wherein the bridge arm energy-storing battery average state of charge comprises an upper bridge arm energy-storing battery average state of charge and a lower bridge arm energy-storing battery average state of charge;

the method comprises the following steps of carrying out feed-forward regulation and charge state balance regulation on the initial bridge arm balance control power reference value according to the actual current and the actual charge state of the energy storage battery, and calculating to obtain bridge arm balance control signals of each phase, wherein the steps comprise:

performing proportion adjustment according to the difference between the total current of the second energy storage battery and the total current of the first energy storage battery, and calculating to obtain a second feedforward adjustment quantity of each phase;

performing proportional integral adjustment according to the difference between the average state of charge of the upper bridge arm energy storage battery and the average state of charge of the lower bridge arm energy storage battery, and calculating to obtain a second state of charge balance adjustment quantity of each phase;

calculating the sum of the initial bridge arm balance control power reference value, the second feedforward regulating quantity and the second charge state balance regulating quantity to obtain the bridge arm balance control power reference value of each phase;

and calculating to obtain the bridge arm balance control signal of each phase according to the bridge arm balance control power reference value.

10. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of the preceding claims 1 to 9 when executing the computer program.

Technical Field

The invention belongs to the technical field of power quality and energy storage control, and particularly relates to a control method of an energy storage railway power regulator and terminal equipment.

Background

A Railway Power Conditioner (RPC) is a comprehensive compensation device applied to Railway electric energy quality management occasions, and can balance load active Power, compensate reactive Power and balance Power grid current. The railway power regulator based on Modular Multilevel Converter (MMC) is called MRPC, and MRPC has the advantages of high topological modularization degree, high AC output quality and small filter device, is very suitable for high-voltage and large-capacity compensation occasions, can save a step-down transformer when being connected with a traction network, and is widely used when the railway electric energy quality is controlled. If an energy storage system is added on the direct current side of the MRPC submodule, the problem of three-phase imbalance in a railway traction system can be solved, the quality of electric energy is improved, the energy of train braking can be fully utilized by the aid of the energy storage system, the efficiency of the system is improved, and the performance stability of a locomotive system is guaranteed.

However, in the study of the energy storage MRPC, it is usually necessary to add a DC/DC converter (DC/DC converter) to each MRPC submodule on the DC side to connect the energy storage device, so that the MRPC has the energy storage capability. However, the number of the MRPC sub-modules is large, the method is high in cost and poor in economy, the control coupling between control instructions of the existing control method is strong, the control is complex, and the reliability of the energy storage MRPC system cannot be guaranteed when part of the sub-modules fail.

Disclosure of Invention

In view of this, the embodiment of the invention provides a control method of an energy storage railway power regulator and a terminal device, and aims to solve the problems of strong coupling and complex control of the control method of the energy storage railway power regulator in the prior art.

In order to achieve the above object, a first aspect of the embodiments of the present invention provides a method for controlling an energy storage railway power regulator, which is applied to an energy storage railway power regulator having an energy storage half-bridge converter unit formed by connecting a half-bridge converter, a dc voltage stabilizing capacitor and an energy storage unit in parallel, the method including:

A second aspect of the embodiments of the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps of the method according to the first aspect when executing the computer program.

Compared with the prior art, the embodiment of the invention has the following beneficial effects: compared with the prior art, the invention is applied to the energy storage railway power regulator formed by connecting the half-bridge converter unit, the direct-current voltage-stabilizing capacitor and the energy storage unit in parallel in the energy storage half-bridge converter unit. Because the energy storage half-bridge converter unit in the energy storage railway power regulator is formed by connecting the half-bridge converter and the energy storage unit in parallel, the switching states of the switching devices in the half-bridge converter and the energy storage unit can be decoupled, the half-bridge converter and the energy storage unit can be conveniently and independently controlled, and the coupling of the control method of the energy storage railway power regulator is reduced. In the control method of the energy storage railway power regulator, the current compensation processing is carried out on the load current of each phase of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and a first modulation signal of alternating current control is obtained through calculation; performing circulation control processing based on the obtained compensation current of each phase of the energy storage railway power regulator and the capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit, and calculating to obtain a second modulation signal for circulation control; performing double-loop control on the basis of the capacitor voltage and the acquired actual current and the actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and calculating to obtain a third modulation signal controlled by the unit; and controlling the half-bridge converter unit and the energy storage half-bridge converter unit in the energy storage railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal. The energy storage system formed by all the energy storage units in the energy storage railway power regulator can automatically compensate the energy of the energy storage railway power regulator for compensating the load, the calculation of reference instructions in the control process is reduced, the coupling between the control instructions is reduced, and the control complexity is further reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a structural topology diagram of an energy storage railway power conditioner provided by an embodiment of the invention;

fig. 2 is a structural topology diagram of an energy storage half-bridge converter unit provided by an embodiment of the invention;

fig. 3 is a topology diagram of a half-bridge converter unit according to an embodiment of the present invention;

FIG. 4 is a schematic flow chart of an implementation of a control method for an energy storage railway power conditioner according to an embodiment of the present invention;

FIG. 5 is an overall control block diagram of an energy storage railway power conditioner provided by an embodiment of the invention;

FIG. 6 is an AC current control block diagram provided by an embodiment of the present invention;

FIG. 7 is a block diagram illustrating the generation of a compensated current reference command according to an embodiment of the present invention;

FIG. 8 is a flowchart illustrating the calculation of the first equivalent current and the second equivalent current according to an embodiment of the present invention;

FIG. 9 is a block diagram of circulation control provided by an embodiment of the present invention;

fig. 10 is a block diagram of generation of a phase equalization control signal and a bridge arm equalization control signal according to an embodiment of the present invention;

FIG. 11 is a control block diagram of cell capacitor voltage equalization control and direct current control provided by an embodiment of the present invention;

FIG. 12 is a block diagram of the generation of a first control signal and a second control signal provided by an embodiment of the present invention;

fig. 13 is a waveform diagram of compensation current of each phase corresponding to simulation condition 1 according to the embodiment of the present invention;

fig. 14 is a voltage waveform diagram of the capacitor of each unit corresponding to simulation condition 1 according to the embodiment of the present invention;

fig. 15 is a waveform diagram of charging current of an energy storage battery corresponding to simulation condition 1 according to an embodiment of the present invention;

fig. 16 is an actual SOC waveform diagram of the energy storage battery corresponding to the simulation condition 1 provided in the embodiment of the present invention;

FIG. 17 is a schematic diagram of an energy storage railway power conditioner control provided by an embodiment of the present invention;

fig. 18 is a schematic diagram of a terminal device according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

The electrified railway has the advantages of large passenger capacity, strong transportation capacity, safety, reliability, high punctuation rate and the like. However, the power supply mode and load characteristics of the traction power supply system bring a series of power quality problems to the railway power supply system, affect the safe and reliable operation of the load locomotive, reduce the power supply quality of the power grid, and even threaten the stable operation of the adjacent power supply/utilization systems (such as wind power plants/photovoltaic power stations).

The unbalanced current of the power grid is a main power quality problem of rail transit at present. The traction power supply network is a symmetrical three-phase power network, but the railway load is a single-phase load, so that the problem of unbalanced three-phase current is caused, and negative-sequence current is formed on the side of the power network, so that electric equipment and loads are adversely affected. The RPC can balance active current, compensate reactive current and harmonic current, and solve the problem of negative sequence current.

The traditional RPC adopts a two-level converter as a converter structure, a traction feeder needs to be connected to the converter through a step-down transformer and is limited by a switching device, and the system voltage is low and the capacity is limited. In large-capacity application occasions, a plurality of RPCs are often required to be operated in parallel, so the system cost is high and the control is complex. Based on this problem, MRPC has been proposed. Compared with the traditional RPC, the MRPC has the characteristics of high voltage level, large compensation capacity, small alternating current filter device, low device switching frequency and the like, and also has the advantages of high modularization degree, good expansibility and redundancy, no need of a step-down transformer and the like. Among the two-leg MRPC, the three-leg MRPC, and the four-leg MRPC, the three-leg MRPC has advantages of low dc bus voltage, few switching devices, simple control, low loss, and no need for an isolation transformer.

In addition, the electric locomotive generates a large amount of energy when braking. If the braking energy is dissipated, waste is generated, and the performance (such as heat generation) of the locomotive system may be deteriorated in the braking process; if the braking energy is fed back to the power grid or stored through the energy storage device, the method has important significance.

Therefore, an energy storage system is added to the traditional RPC direct current bus, and the problems of current imbalance and braking energy recovery can be solved at the same time. If an energy storage system is added on the direct current side of the MRPC sub-module, distributed energy storage of the system can be realized, the voltage of the energy storage module can be reduced, the energy storage efficiency is improved, and meanwhile the modularization degree and redundancy of the energy storage system can be increased. However, the railway power regulator based on the MMC also needs to solve the problem of balance control between sub-module capacitance voltage and battery State of Charge (SOC). In addition, the energy storage railway power regulator in the prior art also has the problems of high energy storage cost, poor reliability, strong coupling of a control method, inflexible control and complex control method.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

Fig. 1 shows a structural topology diagram of an energy storage railway power regulator applied in an embodiment of the present invention, and as shown in fig. 1, an energy storage railway power regulator 10 in an embodiment of the present invention may include a first bridge arm module 11, a second bridge arm module 12, and a third bridge arm module 13 connected in parallel.

The first end of the first bridge arm module 11, the first end of the second bridge arm module 12 and the first end of the third bridge arm module 13 are respectively used for connecting a traction power supply network.

Each bridge arm module comprises an alternating current filter inductor L_sThe upper bridge arm submodule and the lower bridge arm submodule which have the same connecting structure and are connected in series with each other, and the alternating current filter inductor L_sOne end of the bridge arm module is connected between the upper bridge arm sub-module and the lower bridge arm sub-module, and the other end of the bridge arm module is used as the first end of the corresponding bridge arm module; each bridge arm sub-module comprises at least two converter units which are connected in series and have the same number, and at least two converter units of at least one bridge arm sub-module in each bridge arm sub-module comprise a half-bridge converter unit HB_MjkAnd an energy storage Half Bridge (HBIB) converter unit_NjkEnergy-storing half-bridge converter unit HBIB_NjkThe energy storage unit, the half-bridge converter and the direct current voltage-stabilizing capacitor are connected in parallel to form the energy storage device.

Optionally, each bridge arm submodule may further include a bridge arm filter inductor L_armBridge arm filter inductor L_armEach bridge arm submodule comprises at least two converter cells connected in series.

Since at least two converter cells of at least one of the bridge arm sub-modules of the energy storage Railway Power regulator of the present embodiment include both the half-bridge converter cells and the energy storage half-bridge converter cells, the energy storage Railway Power regulator can be referred to as a Hybrid modular multilevel converter (Hybrid MMC rail Power Conditioner, HMRPC). As shown in FIG. 1, in the figure, u_A、u_B、u_CThe three-phase power grid supplies power to the loads of the alpha-phase electric locomotive and the beta-phase electric locomotive through the V/V traction transformer, and the current of the alpha-phase load and the current of the beta-phase load are i respectively_αL、i_βL. The first end of the first bridge arm module 11, the first end of the second bridge arm module 12 and the first end of the third bridge arm module 13, i.e. the ac filter inductance L in each bridge arm module_sThe other end of the first and second connecting lines are respectively used for connecting the secondary side of the V/V traction transformerThree ports of the coil. The load is a single-phase load, so the primary side current i of the V/V traction transformer_A、i_B、i_CUnbalance, requiring compensation of the current i by each phase of HMRPC_acomp、i_bcompAnd i_ccompThe purposes of active power balance, negative sequence compensation and three-phase current balance on the power grid side are achieved.

The HMRPC provided by the embodiment of the invention has the advantages of high MRPC modularization degree, high output quality, large system capacity, low device switching frequency and capability of omitting an isolation transformer and a step-down transformer. And because the number of the converter units in each bridge arm sub-module of the energy storage railway power regulator is the same, as long as at least two converter units of at least one bridge arm sub-module contain both a half-bridge converter unit and an energy storage half-bridge converter unit, when a plurality of bridge arm sub-modules containing both a half-bridge converter unit and an energy storage half-bridge converter unit exist, the number of the HBIB converter units in each bridge arm sub-module can be configured differently, so that the energy storage cost can be reduced, and the flexibility of the topological structure of the energy storage railway power regulator can be improved. And because the energy storage half-bridge converter unit is formed by connecting the energy storage unit, the half-bridge converter and the direct-current voltage-stabilizing capacitor in parallel, the switching states of the switching devices in the half-bridge converter and the energy storage unit can be decoupled, the independent control of the half-bridge converter and the energy storage unit is realized, the independent control of the output power of the energy storage unit in the energy storage half-bridge converter unit is further realized, the coupling of the control method of the energy storage railway power regulator is favorably reduced, the control method of the energy storage railway power regulator with simple control and strong universality is designed, the flexibility of the control method of the energy storage railway power regulator is improved, the working condition of partial energy storage unit faults can be coped with, and the reliability of the energy storage railway power regulator is improved.

Alternatively, as shown in fig. 2, each energy storing half-bridge converter cell HBIB_NjkThe method can comprise the following steps: energy storage battery Bat and energy storage battery filter inductor L_bSwitch tube S₅Switch tube S₆Diode D₅Diode D₆Formed energy storage unit, half-bridge converter HB and direct current voltage stabilizationCapacitor C₂。

Wherein, the positive pole of the energy storage battery Bat and the filter inductance L of the energy storage battery_bIs connected with the negative pole of the energy storage battery Bat and the switching tube S respectively₆Source electrode of (2), diode D₆Positive electrode, DC voltage-stabilizing capacitor C₂Is connected to the first end of the half-bridge converter HB; first end of half-bridge converter HB as energy-storage half-bridge converter unit HBIB_NjkAn input or output of; energy storage battery filter inductance L_bIs connected with the other end of the switch tube S₅Source electrode of (1) and switching tube S₆Between the drain electrodes of (1); switch tube S₅And a diode D₅Is connected with the positive pole of the switching tube S₅Respectively with a diode D₅Negative electrode of (1), DC voltage-stabilizing capacitor C₂The other end of the half-bridge converter HB is connected with the third end of the half-bridge converter HB; switch tube S₆And a diode D₆The negative electrode of (1) is connected; switch tube S₅Grid and switching tube S₆The grid of the grid is used for inputting a first control signal; second end of half-bridge converter HB as energy-storage half-bridge converter unit HBIB_NjkAn output or an input.

Alternatively, as shown in fig. 3, each half-bridge converter cell HB_MjkThe method can comprise the following steps: switch tube S₁Switch tube S₂Diode D₁And a diode D₂Formed half-bridge converter HB and capacitor C₁。

Switch tube S₁And diode D₁Is connected as the third end of the half-bridge converter HB, and a switching tube S₂Source and diode D₂The positive electrode of the half-bridge converter HB is connected with the positive electrode of the first half-bridge converter HB; switch tube S₁Source electrode and switch tube S₂The drain of the half-bridge converter HB is connected to the first terminal of the half-bridge converter HB; switch tube S₁And a diode D₁The positive electrode of (1) is connected; switch tube S₂And a diode D₂The negative electrode of (1) is connected; capacitor C₁Is connected to the third terminal of the half-bridge converter HB, a capacitor C₁Is connected to a first end of a half-bridge converter HB; switch tube S₁Grid and switching tube S₂Is used for inputting a second control signal.

Wherein, the first end of the half-bridge converter HB is used as a half-bridge converter unit HB_MjkAn input or output of; the second terminal of the half-bridge converter HB serves as a half-bridge converter cell HB_MjkAn output or an input.

In this embodiment, the DC side of the HB converter unit and the capacitor C₁The HBIB converter unit is additionally provided with a battery energy storage structure on the basis of the HB converter unit and is connected with a direct current capacitor C through a half-bridge converter₂Connection, L_bThe filter inductor is an energy storage battery filter inductor. By means of a second control signal, the switching tube S is changed₁～S₄The switching state of the bridge arm submodule can control the output voltage of the unit to be equal to the voltage of the capacitor or zero, and the output voltage of the bridge arm submodule is equal to the sum of the output voltages of the unit. The HBIB converter unit can change the switching tube S through the first control signal₅、S₆Thereby controlling the energy storage and release of the battery. The decoupling of the switching states of the switching devices in the half-bridge converter unit and the energy storage unit is realized, so that the energy storage system and the HMRPC system exchange energy, and the HMRPC system further exchanges energy with a load through an alternating current end.

The first control signal and the second control signal may be obtained by an energy storage railway power regulator control method applied to the energy storage railway power regulator of the embodiment. And all energy storage units in the energy storage railway power regulator form an energy storage system. As shown in fig. 4, the control method is detailed as follows:

before the control of the energy storage railway power regulator, the operation parameters of the energy storage railway power regulator need to be acquired. The operation parameters may include the load current i of each phase of the electric locomotive load corresponding to the energy storage railway power regulator_αL、i_βLCompensation current i of each phase of energy storage railway power regulator_acomp、i_bcompAnd i_ccompFirst capacitor voltage U of each half-bridge converter cell in an energy-storing railway power conditioner_{jkl_sm}And each energy storage half-bridge transformer in the energy storage railway power regulatorSecond capacitor voltage U of converter unit_{jkz_sm}Actual current i of energy storage battery_{jkz_bat}And the actual state of charge SOC of the energy storage battery_jkz。

Wherein, the variable subscript j ═ a, b, c represents a phase, b phase or c phase in HMRPC, k ═ p, n represents upper bridge arm submodule p or lower bridge arm submodule n, l ═ 1,2, … M_jkDenotes the number of HB converter cells, M_jkThe total number of HB converter cells included in the k bridge arm sub-modules of the bridge arm module corresponding to j in HMRPC is represented, and z is 1,2, … N_jkDenotes the number of HBIB converter units, N_jkAnd the total number of HBIB converter units included in the k bridge arm sub-modules of the bridge arm module corresponding to the j in the HMRPC is shown.

In which the following variables in the energy storage railway power conditioner system are defined in connection with fig. 1 (where the voltage is referenced to feeder ground):

alpha, beta phase load voltage u_α、u_βRespectively as follows:

wherein, U_sFor the feed line voltage amplitude, ω is the grid angular frequency.

Alpha, beta phase load current i_αL、i_βLRespectively as follows:

wherein, I_α、I_βThe load current amplitude of alpha and beta phases, theta_α、θ_βIs the load power factor angle.

a. b and c phase compensating current i_acomp、i_bcompAnd i_ccompIs defined as:

wherein，I_a、I_bA, b phase compensating current amplitude, theta_a、θ_bAre respectively represented by u_α、u_βIs the compensation current phase angle of the reference phase.

Actual circulation of each phase i_jcirIs defined as:

i_jcir＝(i_jp+i_jn)/2 (4)；

wherein i_jpAnd i_jnThe bridge arm currents of the j-phase upper bridge arm submodule and the j-phase lower bridge arm submodule are respectively.

Common mode voltage u_comIs defined as:

wherein u is_a、u_bAnd u_cIs the HMRPC AC terminal voltage.

Illustratively, the overall control function of the energy storage railway power conditioner is described in conjunction with fig. 5 as follows:

the current reference instruction generation module collects alpha and beta phase load current i_αL、i_βLCalculating the compensation current reference instruction of each phase at the AC side of the HMRPCSo as to balance the three-phase current on the power grid side. The alternating current control module refers each phase compensation current to an instructionCompensating current i with each phase of HMRPC_jcompTo generate a first modulation signal u, to be fed to a Proportional Resonant Regulator (PR)_jcAnd controlling each phase compensation current of the HMRPC to track a given value (each phase compensation current reference instruction). In this embodiment, since the total energy control loops of all converter units of the energy storage railway power regulator change the power exchanged between the HMRPC and the load, the power exchanged between the load and the HMRPC under each phase of compensation current reference instruction after the total energy control loops of all converter units are removed is equal to the expected energy storage systemThe power output, and therefore, the present embodiment does not utilize the total energy control loop of all converter cells to adjust the phase compensation current reference command.

And the circulating current control module inhibits circulating current double-frequency fluctuation and balances capacitor voltage of the interphase module and capacitor voltage between the bridge arm submodules. Reference value of circulation of each phaseObtained by a calculation module and is in contact with the actual circulation current i of each phase_jcirError, interphase balance control signalBridge arm balance control signalA common input Proportional-Integral Resonant Regulator (PIR) to obtain a second modulation signal u_jccTo achieve the functions of circulation control and balance control. The algorithm of the calculation module is changed, and the actual current i of the energy storage battery can be utilized_{jkz_bat}The current of the battery is used as the feedforward control to carry out the feedforward control on the interphase balance control and the bridge arm balance control, on the basis, the third modulation signal of the unit control is obtained by double-loop control calculation based on the voltage outer loop and the current inner loop, so the actual charge state of each energy storage battery is easy to be different, and the actual charge state SOC of the energy storage battery can be utilized_jkzAnd performing SOC balance control on the interphase balance control and the bridge arm balance control. So as to improve the equalizing effect of the capacitor voltage of the sub-modules between phases and between bridge arms.

The unit balance control is used for balancing capacitance voltage among all units in the bridge arm submodule. Because the energy storage batteries are controlled based on double-ring control of the voltage outer ring and the current inner ring, the actual charge states of the energy storage batteries are easy to be different, and the SOC balance control of the energy storage half-bridge converter unit is realized by adjusting the modulation wave of the half-bridge converter unit in the energy storage half-bridge converter unit. Because the energy storage battery is controlled based on the double-loop control of the voltage outer loop and the current inner loop, the actual current of the energy storage battery is controlled by the second electricityThe capacitance voltage outer loop. When the actual charge state of the energy storage battery is lower than the average charge state of the bridge arm energy storage battery, increasing second capacitor voltage, and charging the energy storage battery under the action of an outer ring of the second capacitor voltage so as to increase the actual charge state of the energy storage battery; and otherwise, when the actual charge state of the energy storage battery is higher than the average charge state of the bridge arm energy storage battery, reducing the voltage of the second capacitor, and discharging the energy storage battery under the action of an outer ring of the voltage of the second capacitor so as to reduce the actual charge state of the energy storage battery. Thus, the first capacitor voltage U of the half-bridge converter unit is obtained by sampling_{jkl_sm}Second capacitor voltage U of energy storage half-bridge converter unit_{jkz_sm}Calculating the average voltage of the capacitors of the bridge arm sub-modules, and adjusting the error between the average voltage and the first capacitor voltage by a Proportional-Integral Regulator (PI) to obtain a first sub-modulation signal u_jklc. The error between the voltage of the first sub-modulation signal and the voltage of the second capacitor is regulated through PI, and then the SOC balance control of the energy storage half-bridge converter unit is added to obtain a second sub-modulation signal u_jkzc. First sub-modulation signal u in the final third modulation signal_jklcAnd a second sub-modulated signal u_jkzcAnd also with bridge arm current i_jkIs related to the direction of (a). The energy storage battery is controlled to work in a double-loop control mode of a voltage outer loop and a current inner loop and passes through a second capacitor voltage U_{jkz_sm}And a capacitance reference voltageThe difference value of the current and the current of the energy storage battery is subjected to PI regulation, and the regulation result is opposite to the actual current i of the energy storage battery_{jkz_bat}Performing PI regulation on the difference value to generate a third sub-modulation signal u in a third modulation signal_{jkz_bat}。

Modulating the output part, the modulation signal of the half-bridge converter cell on the MMC side, i.e. the switching tube S in FIGS. 2 and 3₁～S₄Control signal of (d), from u_jc、u_jcc、u_jklcAnd u_jkzcJointly generating, under modulation, a (second control signal) switching signal S_jklAnd S_jkzRespectively controlling the switching tubes S₁、S₂And S₃、S₄。S_{jkz_bat}For battery-side half-bridge conversion(first control signal) switching signal of the device unit, i.e. S₅、S₆Switching signal of (d), from u_{jkz_bat}And (4) generating.

By the control method of the energy storage railway power regulator, the purposes of balancing the current of a power grid and improving the energy utilization rate by using an energy storage system can be achieved. And in the control process, the second capacitor voltage, the actual current and the actual state of charge of the energy storage battery and the first capacitor voltage of each half-bridge converter unit are utilized, when the energy storage unit of any energy storage half-bridge converter unit fails, the corresponding energy storage unit can be directly bypassed, and therefore the reliability of the whole energy storage railway power regulator is ensured. The flexibility of the control method of the energy storage railway power regulator is improved. And double-loop control is carried out on the basis of the first capacitor voltage, the second capacitor voltage, the actual current of the energy storage battery of each energy storage half-bridge converter unit and the actual charge state of the energy storage battery, and a third modulation signal controlled by the unit is obtained through calculation, so that an energy storage system formed by all energy storage units in the energy storage railway power regulator can automatically compensate the energy of the energy storage railway power regulator for compensating the load, the calculation of reference instructions in the control process is reduced, and the control complexity is further reduced.

The following description of the control functions of the energy storage railway power conditioner control method through steps 101 to 104 with reference to fig. 4 to 12 is as follows:

step 101, performing current compensation processing on each phase of load current of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and calculating to obtain a first modulation signal for controlling the alternating current.

In this embodiment, each phase of load current is compensated by the energy storage system, the reactive current compensation, the active current balance and the negative sequence current compensation to obtain a compensated load current, and the compensated load current is subtracted from the actual load current to obtain a compensation current reference command. Reference command of compensating current for each phaseCompensating current i with each phase of HMRPC_jcompError value ofForming a first modulated signal u via a PR regulator_jcAnd controlling each phase compensation current of the HMRPC to track a given value (each phase compensation current reference instruction).

Optionally, with reference to fig. 6 and fig. 7, performing current compensation processing on load currents of each phase of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and calculating to obtain a first modulation signal for controlling the ac current may include:

acquiring a first equivalent current and a second equivalent current; carrying out current compensation processing according to the load current of each phase, the first equivalent current and the second equivalent current, and calculating to obtain a compensation current d-axis component; carrying out dq conversion on each phase of load current, and calculating to obtain a q-axis component of the load current; multiplying the q-axis component of the load current by-1 to obtain a q-axis component of the compensation current; carrying out dq inverse transformation according to the d-axis component and the q-axis component of the compensation current, and calculating to obtain a compensation current reference instruction of each phase; and calculating to obtain a first modulation signal controlled by the alternating current according to the compensation current of each phase and the compensation current reference instruction of each phase.

The first equivalent current is equivalent current of active power output to the alpha phase by the energy storage system through the energy storage railway power regulator at the alternating current side of the energy storage railway power regulator, and the second equivalent current is equivalent current of active power output to the beta phase by the energy storage system through the energy storage railway power regulator at the alternating current side of the energy storage railway power regulator.

Optionally, obtaining the first equivalent current and the second equivalent current may include:

the method comprises the steps of obtaining alpha-phase load active power and beta-phase load active power of an electric locomotive load corresponding to an energy storage railway power regulator, the maximum output power of an energy storage system of the energy storage railway power regulator, the allowed maximum charge state of an energy storage battery of each energy storage half-bridge converter unit in the energy storage railway power regulator and the allowed minimum charge state of the energy storage battery.

And judging whether the active power of the alpha-phase load, the active power of the beta-phase load and the actual state of charge of the energy storage battery meet preset conditions, wherein the preset conditions are that the sum of the active power of the alpha-phase load and the active power of the beta-phase load is larger than zero and the actual state of charge of each energy storage battery is larger than the corresponding allowable minimum state of charge of the energy storage battery, or the sum of the active power of the alpha-phase load and the active power of the beta-phase load is smaller than zero and the actual state of charge of each energy storage battery is smaller than the corresponding allowable maximum state of charge of the energy storage battery.

If the active power of the alpha-phase load, the active power of the beta-phase load and the actual state of charge of the energy storage battery meet preset conditions, calculating to obtain an absolute value of the difference between the active power of the alpha-phase load and the active power of the beta-phase load, and judging whether the absolute value is less than or equal to the maximum output power of the energy storage system.

If the absolute value is less than or equal to the maximum output power of the energy storage system, the method is based onAnd acquiring a first equivalent current and a second equivalent current.

If the absolute value is greater than the maximum output power of the energy storage system, the method is based onAnd acquiring a first equivalent current and a second equivalent current.

And if the alpha-phase load active power, the beta-phase load active power and the actual charge state of the energy storage battery do not meet the preset conditions, determining that the first equivalent current and the second equivalent current are both zero.

Wherein i_αbIs a first equivalent current, i_βbIs the second equivalent current, P_bmFor maximum output power of the energy storage system, U_sFor the amplitude of the feed line voltage, P_αLFor alpha-phase load active power, P_βLFor beta-phase loaded active power, F₁＝sin(ωt-π/6)，F₂Sin (ω t-pi/2), ω is the grid angular frequency, f₁、f₂、f₃Are coefficients.

In conjunction with FIG. 8, in this figure "&&"represents a logical AND", "|" represents a logical OR ", P_bmFor the maximum output power of the energy storage system, which can be obtained directly, P_αLAnd P_βLFor the alpha and beta phase load active power, it can be calculated by equation (6), i_αLdAnd i_βLdIs alpha and beta phase load active current and is obtained by current active separation, SOC_jkz、SOC_maxAnd SOC_minThe actual SOC of the energy storage battery, the allowed maximum SOC of the energy storage battery and the allowed minimum SOC of the energy storage battery of the HBIB converter unit are respectively.

Wherein, I_αLd、I_βLdThe active current amplitude of the alpha and beta phase load is obtained.

Firstly, judging whether the SOC of the energy storage system meets the energy storage or release condition. If P_αL+P_βL>0, namely the total alpha and beta phase load consumes active power, and at the moment, if the actual SOC of each energy storage battery meets the SOC_jkz>SOC_minThe energy storage device allows for energy release; if P_αL+P_βL<0, indicating that the alpha and beta phase total load feeds back active power to the power grid, and if the SOC is in the moment_jkz<SOC_maxThe energy storage device allows energy storage; otherwise let i_αb＝i_βbAnd 0, namely the energy storage system does not work.

And further judging whether the energy storage system can balance the active power of the alpha phase and the beta phase. If P_αL-P_βL|≤P_bmThe active power of the alpha phase and the active power of the beta phase are equal after the energy storage system is compensated; if P_αL-P_βL|>P_bmAnd the absolute value of the active power of the compensation load of the energy storage system is larger. Thus, i can be calculated from FIG. 8_αbAnd i_βbIn the figure, F₁＝sin(ωt-π/6)，F₂＝sin(ωt-π/2)，f₁、f₂And f₃Is a coefficient, the calculation formula is:

before and after the energy storage system works, active power output by HMRPC to alpha and beta phases is changed, and negative sequence compensation output is also changed. The present embodiment therefore prioritizes the compensation effect of the energy storage system when calculating the compensation current. In FIG. 7, the α, β phase load current i_αLAnd i_βLRespectively with the first equivalent current i_αbAnd a second equivalent current i_βbAdding the energy storage system and giving priority to the compensation of the energy storage system to obtain the current after the compensation of the energy storage system, and recording the current as i_αlAnd i_βlAnd then calculating the compensation reactive current, the negative sequence current and the balance active current of the HMRPC. Specifically, for i_αlAnd i_βlPerforming active power separation according to the instantaneous reactive power theory to obtain a current i after reactive power compensation_αlpAnd i_βlp. Therefore, the grid current is calculated by the formula (8) according to the alpha and beta load currents, then the grid current is converted to a dq coordinate system by the formula (9), and a direct-current component of the d-axis current is extracted by a Second-Order generalized Integrator (SOGI) and multiplied by a proportionality coefficient G to obtain I_d。I_dI is the compensated three-phase power grid is balanced i_αlAnd i_βlAnd d-axis component in dq coordinate system, and q-axis component after compensation is zero. And finally, respectively subtracting the compensated load current from the load current of each phase under the dq coordinate system to obtain the initial compensation current. Specifically, i is_αLAnd i_βLTransformation into dq coordinate system, I_dWith the d-axis component i of the load current_dSubtracting to obtain the d-axis component of the compensation current and the q-axis component i of the load current_qMultiplying-1 to obtain a q-axis component of the compensation current, and performing inverse transformation on the obtained d and q-axis components of the compensation current to obtain a final reference instruction of each phase of the compensation currentIn FIG. 7, the scale factorTheta is phase-locked u_APhase, i_ddThe d-axis component of the current after the energy storage system compensation and reactive compensation.

Wherein k is_tIs the transformation ratio of the traction transformer.

Wherein i_dAnd i_qRespectively, a d-axis component and a q-axis component of the load current in a dq coordinate system.

In this embodiment, since energy compensation of the energy storage system is automatically performed when the cell voltage changes due to energy exchange between HMRPC and the load, the physical quantity change and energy transfer principle of the system under the control method are analyzed: the compensation current reference instruction is changed, the output power of the load to the HMRPC is controlled to be positive (negative), at the moment, the capacitor voltage of the unit has a rising (lowering) trend, the HB converter unit does not have an energy storage battery, so that the corresponding voltage rises (lowers), the capacitor voltage of the HBIB converter unit is kept stable under the control of the capacitor voltage ring of the energy storage battery, the voltage of the HB converter unit starts to fall (raise) under the action of unit balance control, finally, the voltage of all converter units is kept stable, and the energy exchange between the load and the energy storage system is realized. Since the total energy control loops of all the converter units of the energy storage railway power regulator change the power exchanged between the HMRPC and the load, when the compensation current reference command of each phase is obtained, the total energy control loops of all the converter units are not required to be adjusted.

And 102, performing circulation control processing based on the obtained compensation current of each phase of the energy storage railway power regulator and the capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit, and calculating to obtain a second modulation signal for circulation control.

Referring to fig. 9, a circulating current reference value of each phase can be calculated based on the compensation current of each phase, the first capacitor voltage and the second capacitor voltagePhase equalization control signalAnd bridge arm balance control signalReference value of circulation of each phaseWith actual circulation of each phase i_jcirThe error value of the bridge arm sub-module is equal to the phase equalization control signal formed by the interphase capacitance voltage equalization control and the bridge arm sub-module capacitance voltage equalization controlAnd bridge arm balance control signalSummed as an input to a PIR regulator to form a second modulated signal u_jccThe direct current circulation is stabilized, the secondary circulation is restrained, and the capacitor voltage between phases and between bridge arm submodules is balanced.

Optionally, referring to fig. 9 and fig. 10, performing a circulation control process based on the obtained compensation current of each phase of the energy storage railway power regulator, and the capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit in the energy storage railway power regulator, and calculating to obtain a second modulation signal for circulation control may include:

decomposing the compensation current of each phase, and calculating to obtain a circulation reference value of each phase according to a decomposition result; calculating to obtain a per unit value of the total energy of the first capacitors of all the converter units in each upper bridge arm sub-module and a per unit value of the total energy of the second capacitors of all the converter units in each lower bridge arm sub-module according to the first capacitor voltage and the second capacitor voltage; calculating a per unit value of the total energy reference value of the first capacitor of each bridge arm module according to the obtained capacitor reference voltage; performing proportional integral adjustment according to the difference between the sum of the per-unit value of the total energy of the first capacitor and the per-unit value of the total energy of the second capacitor and the per-unit value of the total energy reference value of the first capacitor, and calculating to obtain an initial phase equilibrium control power reference value of each phase; according to the actual current and the actual state of charge of the energy storage battery, performing feed-forward regulation and state of charge balance regulation on the initial phase balance control power reference value, and calculating to obtain a phase balance control signal of each phase; performing proportional integral adjustment according to the difference between the per-unit value of the total energy of the first capacitor and the per-unit value of the total energy of the second capacitor, and calculating to obtain an initial bridge arm balance control power reference value of each phase; according to the actual current and the actual state of charge of the energy storage battery, performing feed-forward regulation and state of charge balance regulation on the initial bridge arm balance control power reference value, and calculating to obtain bridge arm balance control signals of each phase; and regulating the acquired actual circulation of each phase, the circulation reference value of each phase, the phase balance control signal of each phase and the bridge arm balance control signal of each phase of the energy storage railway power regulator through the proportional-integral resonance regulator, and calculating to obtain a second modulation signal for circulation control.

Wherein each phase of the energy storage railway power regulator is actually circulated i_jcirThe actual circulation current i of each phase can be obtained through calculation of the obtained bridge arm current according to the formula (4) or direct measurement_jcir。

The process of decomposing the compensation current of each phase and calculating the circulating current reference value of each phase according to the decomposition result may be as follows:

the active current and the reactive current of the a and b phase compensation currents in the formula (3) are decomposed to obtain:

wherein, I_P1For the amplitude of the same phase component of the a-phase compensation current and the alpha-phase load voltage, I_Q1Compensating current lag alpha phase load voltage phase for a phaseA 90 ° current component amplitude; i is_P2For the b-phase compensation current and the beta-phase load voltage with the same phase component amplitude, I_Q2The phase of the beta-phase load voltage is 90 DEG in current component amplitude for the phase b compensation current lag.

Calculating j-phase instantaneous power P_jComprises the following steps:

P_j＝U_dci_jcir+(u_j+u_com)i_jcomp (13)；

wherein, U_dcIs the dc bus voltage.

Synthesizing formulas (1), (5), (12) and (13), and solving to obtain a three-phase circulation reference value according to that when the HMRPC system works stably, j-phase instantaneous power has no direct current component, namely the direct current component in the formula is 0

With reference to fig. 10, the interphase balance control and the bridge arm balance control can ensure stable capacitance and voltage between interphase and bridge arm submodules, and can be realized by controlling direct current circulating current and fundamental wave alternating current circulating current respectively. In the following analysis, the capacitance per unit energy values of the HB and HBIB converter cells are defined asAndper unit value is used as superscript^#And (4) showing.

Wherein, the MMC is the per unit value of the total energy of the first capacitors of all the converter units in each corresponding upper bridge arm submoduleAnd the per unit value of the total energy of the second capacitors of all the converter units in the lower bridge arm submoduleCan be calculated as:

initial phase equalization of each phase controls a phase power reference for balancing the capacitive energy of the phase sub-modulesThe following can be calculated by the PI regulator:

wherein the content of the first and second substances,is the per unit value of the first capacitance total energy reference value of each corresponding bridge arm module,is the per unit value of the total energy of the first capacitorAnd per unit value of total energy of second capacitorSum, k_p1、k_i1Respectively are a proportional coefficient and an integral coefficient of interphase balance control.

According to the actual current and the actual state of charge of the energy storage battery, the power reference value is controlled for the initial phase equilibriumAnd performing feed-forward regulation and charge state balance regulation to calculate phase balance control signals of all phases.

Per unit value of total energy of first capacitorAnd per unit value of total energy of second capacitorThe difference value of the initial bridge arm balance control power reference value can be calculated through a PI regulatorComprises the following steps:

wherein k is_p2、k_i2Respectively are a proportional coefficient and an integral coefficient of bridge arm balance control.

And performing feed-forward regulation and charge state balance regulation on the initial bridge arm balance control power reference value according to the actual current and the actual charge state of the energy storage battery, and calculating to obtain bridge arm balance control signals of each phase.

And regulating the acquired actual circulation of each phase, the circulation reference value of each phase, the phase balance control signal of each phase and the bridge arm balance control signal of each phase of the energy storage railway power regulator through the proportional-integral resonance regulator, and calculating to obtain a second modulation signal for circulation control.

Optionally, the feedforward adjustment and the state of charge equalization adjustment are performed on the initial phase equalization control power reference value according to the actual current and the actual state of charge of the energy storage battery, and the phase equalization control signal of each phase is obtained through calculation, which may include:

calculating to obtain the total current of the third energy storage battery of each bridge arm module and the average current of the energy storage batteries of each bridge arm module according to the actual current of the energy storage batteries; performing proportion adjustment according to the difference between the total current of the third energy storage battery and the average current of the energy storage battery, and calculating to obtain a first feedforward adjustment quantity of each phase; calculating to obtain the average charge state of the energy storage batteries of all energy storage half-bridge converter units in the energy storage railway power regulator and the average charge state of the phase energy storage battery corresponding to each bridge arm module according to the actual charge state of the energy storage batteries; performing proportional integral adjustment according to the difference between the average charge state of the energy storage battery and the average charge state of the phase energy storage battery, and calculating to obtain a first charge state balance adjustment quantity of each phase; calculating the sum of the initial phase equilibrium control power reference value, the first feedforward adjustment quantity and the first state of charge equilibrium adjustment quantity to obtain the phase equilibrium control power reference value of each phase; and calculating to obtain the phase equalization control signal of each phase according to the phase equalization control power reference value.

Optionally, the average charge state of the bridge arm energy storage battery includes an average charge state of an upper bridge arm energy storage battery and an average charge state of a lower bridge arm energy storage battery. According to the actual current and the actual state of charge of the energy storage battery, performing feed-forward adjustment and state of charge equalization adjustment on the initial bridge arm equalization control power reference value, and calculating to obtain bridge arm equalization control signals of each phase, wherein the steps can be as follows:

calculating to obtain a first energy storage battery total current of each upper bridge arm submodule and a second energy storage battery total current of each lower bridge arm submodule according to the actual current of the energy storage battery; carrying out proportion adjustment according to the difference between the total current of the second energy storage battery and the total current of the first energy storage battery, and calculating to obtain a second feedforward adjustment quantity of each phase; performing proportional integral adjustment according to the difference between the average state of charge of the upper bridge arm energy storage battery and the average state of charge of the lower bridge arm energy storage battery, and calculating to obtain a second state of charge balance adjustment quantity of each phase; calculating the sum of the initial bridge arm balance control power reference value, the second feedforward regulating quantity and the second charge state balance regulating quantity to obtain bridge arm balance control power reference values of all phases; and calculating to obtain the bridge arm balance control signal of each phase according to the bridge arm balance control power reference value.

When the number of the HBIB converter units included in different corresponding bridge arm modules or different bridge arm sub-modules is different, or the power of the energy storage batteries of different HBIB converter units is different, the energy stored or released by the energy storage system is transferred between the HB and HBIB converter units, and also transferred between phases and among the bridge arm sub-modules.

Wherein i_{jkz_bat}For regulating railway power by storing energyWhen the actual current of the energy storage battery is positive, the capacitor corresponding to the energy storage half-bridge converter unit releases energy, the voltage of the capacitor is reduced, and the voltage of the capacitor corresponding to the energy storage half-bridge converter unit needs to be increased; when the actual current of the energy storage battery is negative, the capacitor voltage of the corresponding energy storage half-bridge converter unit rises, and the capacitor voltage of the corresponding energy storage half-bridge converter unit needs to be reduced. Taking all energy storage half-bridge converter units of all corresponding bridge arm modules or bridge arm sub-modules into consideration as a whole, and calculating the total current i of the first energy storage battery of each upper bridge arm sub-module in the energy storage railway power regulator_{jp_bat}And the total current i of the second energy storage battery of each lower bridge arm submodule_{jn_bat}And the total current i of the third energy storage battery of each bridge arm module_{j_bat}And average current i of energy storage batteries of each bridge arm module_{phav_bat}Respectively as follows:

if the total current i of the third energy storage battery_{j_bat}Is larger than the average current i of the energy storage battery_{phav_bat}If the energy storage power of the phase energy storage system is larger than the three-phase average value or the energy release power of the phase energy storage system is smaller than the three-phase average value, the average value of the capacitor voltage of the phase module is reduced compared with the average value of the capacitor voltage of all modules of the system, and the average value of the capacitor voltage of the phase module needs to be increased; if the total current i of the third energy storage battery_{j_bat}Less than the average current i of the energy storage battery_{phav_bat}The phase module voltage average needs to be reduced.

When the total current i of the first energy storage battery_{jp_bat}Is larger than the total current i of the second energy storage battery_{jn_bat}In the process, the capacitance average voltage of the upper bridge arm submodule needs to be increased, and the capacitance average voltage of the lower bridge arm submodule is reduced; when the total current i of the first energy storage battery_{jp_bat}Is less than the total current i of the second energy storage battery_{jn_bat}In the process, the average voltage of the capacitors of the upper bridge arm sub-modules needs to be reduced, and the average voltage of the capacitors of the lower bridge arm sub-modules needs to be increased.

Thus, eachFirst feedforward adjustment of phase Δ P₁Comprises the following steps:

ΔP₁＝k_p3(i_{j_bat}-i_{phav_bat}) (19)；

wherein k is_p3The proportionality coefficient is feedforward controlled for the phase battery current.

Second feedforward adjustment Δ P for each phase₂Comprises the following steps:

ΔP₂＝k_p4(i_{jn_bat}-i_{jp_bat}) (20)；

wherein k is_p4And the proportional coefficient is feedforward controlled for the current of the bridge arm battery.

The HBIB converter unit capacitor voltage is controlled by the energy storage battery voltage outer ring, so that the SOC of each energy storage battery is easy to be different, and a system SOC balance control strategy is needed. If the SOC of the energy storage battery needs to be increased, the energy storage battery needs to be charged, the voltage of a second capacitor can be increased, and the energy storage battery is charged under the action of an outer ring of the voltage of the second capacitor; if the SOC of the energy storage battery is required to be reduced, the voltage of the second capacitor needs to be reduced. Therefore, the SOC balance control can be realized by adjusting the voltage of the second capacitor.

Calculating to obtain the average state of charge (SOC) of the energy storage batteries of all energy storage half-bridge converter units in the energy storage railway power regulator according to the actual state of charge of the energy storage batteries_avAnd the average state of charge (SOC) of the phase energy storage battery corresponding to each bridge arm module_jAnd the average charge state SOC of the upper bridge arm energy storage battery in the average charge state of the bridge arm energy storage batteries of each bridge arm submodule_jpAnd the average state of charge SOC of the energy storage battery of the lower bridge arm_jnComprises the following steps:

phase SOC balance control may be achieved by adjusting the DC circulating current, so the first state of charge balance adjustment Δ P₁₁Comprises the following steps:

ΔP₁₁＝k_p6(SOC_av-SOC_j)+k_i6∫(SOC_av-SOC_j)dt (22)；

wherein k is_p6、k_i6Respectively, a phase SOC balance control proportional coefficient and an integral coefficient.

The SOC balance control of the bridge arm can be realized by adjusting the alternating current circulating current, so that the second charge state balance adjustment quantity delta P₂₂Comprises the following steps:

ΔP₂₂＝k_p7(SOC_jp-SOC_jn)+k_i7∫(SOC_jp-SOC_jn)dt (23)；

wherein k is_p7、k_i7Respectively is a proportional coefficient and an integral coefficient for the SOC balance control of the bridge arm.

Calculating to obtain a first feedforward regulating quantity delta P₁And a first state of charge equalization adjustment Δ P₁₁Then, the phase equilibrium control power reference value of each phase is calculated according to the formula (24)

The phase equalization control signal for each phase is:

calculating to obtain a second feedforward regulating quantity delta P₂And a second state of charge equalization adjustment Δ P₂₂Then, the bridge arm balance control power reference value of each phase is calculated and obtained according to the formula (26)

The degree of freedom of the alternating current circulation is 3, wherein the fundamental positive sequence circulation and the fundamental negative sequence circulation can be used for bridge arm balance controlControl signal for bridge arm equalizationThe expression is as follows:

wherein, I_z+、I_z-Positive and negative sequence circulating current amplitudes, theta, respectively₊、θ_-Positive sequence circulating phase angle and negative sequence circulating phase angle.

Let theta₊When 0, we get:

wherein the content of the first and second substances,

in this embodiment, when the number of the HBIB converter units included in different corresponding bridge arm modules or different bridge arm sub-modules is different, or the power of the energy storage batteries of different HBIB converter units is different, the energy stored or released by the energy storage system is transferred not only between the HB and the HBIB converter units, but also between the phases and between the bridge arm sub-modules. And the SOC of each energy storage battery in the HBIB converter unit controlled by the energy storage battery voltage outer ring is easy to be different, so that a system SOC balance control strategy is needed. Therefore, battery current feed-forward control, phase SOC balance control and bridge arm SOC balance control are introduced, energy of the energy storage system can be accelerated to be balanced between the interphase bridge arm module and the bridge arm sub-module, the exchange speed of the energy storage system between the HMRPC interphase and the bridge arm is increased, and the stability of the capacitor voltage of the sub-module is facilitated.

And 103, performing double-loop control based on the capacitor voltage, the acquired actual current of the energy storage battery of each energy storage half-bridge converter unit and the actual charge state of the energy storage battery, and calculating to obtain a third modulation signal controlled by the unit.

In this embodiment, as shown in fig. 11, the energy storage batteries of the HBIB converter unit adopt dual-loop control of a voltage outer loop and a current inner loop, and since the actual state of charge of each energy storage battery is likely to be different at this time, SOC equalization control of the energy storage half-bridge converter unit can be achieved by adjusting the modulation wave of the half-bridge converter unit in the energy storage half-bridge converter unit. Because the energy storage battery is controlled based on the double-loop control of the voltage outer loop and the current inner loop, the actual current of the energy storage battery is determined by the voltage outer loop of the second capacitor. When the actual charge state of the energy storage battery is lower than the average charge state of the bridge arm energy storage battery, increasing second capacitor voltage, and charging the energy storage battery under the action of an outer ring of the second capacitor voltage so as to increase the actual charge state of the energy storage battery; and otherwise, when the actual charge state of the energy storage battery is higher than the average charge state of the bridge arm energy storage battery, reducing the voltage of the second capacitor, and discharging the energy storage battery under the action of an outer ring of the voltage of the second capacitor so as to reduce the actual charge state of the energy storage battery.

Optionally, double-loop control is performed based on the capacitor voltage and the obtained actual current of the energy storage battery and the actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and a third modulation signal controlled by the unit is obtained through calculation, which may include:

calculating to obtain the average energy storage battery current of the bridge arms of each bridge arm submodule according to the actual current of the energy storage battery; calculating to obtain the average voltage of the capacitor of each bridge arm submodule according to the first capacitor voltage and the second capacitor voltage; adjusting according to the first capacitor voltage, the average bridge arm energy storage battery current and the obtained bridge arm current of each bridge arm submodule, and calculating to obtain a first sub-modulation signal of each half-bridge converter unit; calculating to obtain the average charge state of the bridge arm energy storage battery of each bridge arm submodule according to the actual charge state of the energy storage battery; adjusting according to the second capacitor voltage, the actual current of the energy storage battery, the average voltage of the capacitor, the average current of the energy storage battery of the bridge arm, the actual charge state of the energy storage battery, the average charge state of the energy storage battery of the bridge arm and the bridge arm current, and calculating to obtain a second sub-modulation signal of each energy storage half-bridge converter unit; adjusting a voltage outer ring and a current inner ring according to the obtained capacitance reference voltage and the second capacitance voltage of the energy storage railway power regulator and the actual current of the energy storage battery, and calculating to obtain a third sub-modulation signal of each energy storage half-bridge converter unit; and taking the first sub-modulation signal, the second sub-modulation signal and the third sub-modulation signal as a third modulation signal for unit control.

Optionally, the adjusting is performed according to the second capacitor voltage, the actual current of the energy storage battery, the average voltage of the capacitor, the average current of the bridge arm energy storage battery, the actual state of charge of the energy storage battery, the average state of charge of the bridge arm energy storage battery, and the bridge arm current, and the calculating to obtain the second sub-modulation signal of each energy storage half-bridge converter unit may include:

calculating a first difference value between the average voltage of the capacitor and the voltage of the second capacitor, and performing proportional-integral adjustment on the first difference value to obtain an initial modulation signal of each energy storage half-bridge converter unit; calculating a second difference value between the actual current of the energy storage battery and the average current of the energy storage battery of the bridge arm, and performing proportion adjustment on the second difference value to obtain a battery current feedforward control signal of each energy storage half-bridge converter unit; calculating a third difference value between the average charge state of the bridge arm energy storage battery and the actual charge state of the energy storage battery, and performing proportional-integral adjustment on the third difference value to obtain a charge state balance adjustment signal of each energy storage half-bridge converter unit; calculating the sum of the initial modulation signal, the battery current feedforward control signal and the state of charge balance adjustment signal to obtain an initial second sub-modulation signal of each energy storage half-bridge converter unit; and determining the positive and negative of the initial second sub-modulation signal according to the positive and negative of the bridge arm current, and obtaining the second sub-modulation signal of each energy storage half-bridge converter unit according to the initial second sub-modulation signal after the positive and negative are determined.

Optionally, the voltage outer loop and the current inner loop are adjusted according to the obtained capacitance reference voltage of the energy storage railway power regulator, the obtained second capacitance voltage and the obtained actual current of the energy storage battery, and the third sub-modulation signal of each energy storage half-bridge converter unit is obtained through calculation, and the method may include:

calculating a fourth difference value between the obtained capacitor reference voltage of the energy storage railway power regulator and the second capacitor voltage, and performing proportional integral regulation on the fourth difference value to obtain an energy storage battery discharge current reference value of each energy storage half-bridge converter unit; taking the inverse number of the discharge current reference value of the energy storage battery to obtain the charging current reference value of the energy storage battery of each energy storage half-bridge converter unit; and calculating a fifth difference value between the reference value of the charging current of the energy storage battery and the actual current of the energy storage battery, and performing proportional-integral adjustment on the fifth difference value to obtain a third sub-modulation signal of each energy storage half-bridge converter unit.

In this embodiment, the average current i of the energy storage battery of the bridge arm of each bridge arm submodule in the energy storage railway power regulator is defined_{jk_batav}：

Actual current i of energy storage battery_{jkz_bat}When the voltage of the unit capacitor is positive, the voltage of the unit capacitor is in a descending trend, and the voltage of the unit capacitor needs to be increased; actual current i of energy storage battery_{jkz_bat}When the voltage is negative, namely the energy storage battery discharges, the voltage of the unit capacitor needs to be reduced. When the actual current of the energy storage battery (the actual current of the energy storage battery of the HB converter unit is recorded as 0) is larger than the average current i of the energy storage battery of the bridge arm_{jk_batav}When the voltage of the unit capacitor needs to be increased, the voltage is less than the average energy storage battery current i of the bridge arm_{jk_batav}The cell capacitor voltage is reduced, thereby obtaining a battery current feed-forward control method. The actual current i of the energy storage battery_{jkz_bat}(HB converter unit is 0) and bridge arm average energy storage battery current i_{jk_batav}The difference value of the battery voltage is used as a battery feedforward control signal through a proportional regulator, and a regulating unit modulates the signal to achieve the purpose of feedforward control.

Capacitor average voltage U of bridge arm submodule in energy storage railway power regulator_{jk_armav}Comprises the following steps:

average voltage U of capacitor_{jk_armav}And a first capacitor voltage U_{jkl_sm}Error value ofThe over-PI regulator is summed with the battery feed-forward control signal as a first initial sub-modulation signal for each HB converter unit in the energy storage railway power regulator. Bridge arm current i_jkInfluence the final first sub-modulated signal u_jklcPositive and negative of (1)_jkIf the voltage is positive, multiplying the first initial sub-modulation signal by 1, and increasing the duty ratio of the converter unit with lower unit capacitor voltage to increase the charging time; i.e. i_jkWhen negative, the first initial sub-modulation signal is multiplied by-1, reducing its discharge time.

Combining with the formula (21), according to the actual state of charge SOC of the energy storage battery_jkzAnd the average charge state SOC of the bridge arm energy storage battery of each bridge arm submodule can be obtained through calculation_jkI.e. average state of charge SOC of upper bridge arm energy storage battery_jpOr the average state of charge SOC of the energy storage battery of the lower bridge arm_jn. On the basis, the average voltage U of the capacitor_{jk_armav}And a second capacitor voltage U_{jkz_sm}Is used as an initial modulation signal of each HBIB converter unit in the energy storage railway power regulator through the PI regulator and is compared with the actual current i of the energy storage battery_{jkz_bat}And bridge arm average energy storage battery current i_{jk_batav}The second difference value of the voltage difference value is subjected to battery current feedforward control signals after passing through a P regulator and the average state of charge (SOC) of the bridge arm energy storage battery_jkAnd the actual state of charge SOC of the energy storage battery_jkzThe third difference value of the first sub-modulation signal u is summed to serve as an initial second sub-modulation signal u of each HBIB converter unit in the energy storage railway power regulator after passing through the PI regulator_jkzcAnd determining the first sub-modulation signal u_jklcIs similar according to the bridge arm current i_jkDetermines the final second sub-modulation signal u_jkzcPositive and negative.

Direct acquisition of capacitive reference voltageSecond capacitor voltage U_{jkz_sm}And a capacitance reference voltagePerforming PI regulation on the difference value of the twoThe result is the inverse number of the actual current i of the energy storage battery_{jkz_bat}Performing PI regulation on the difference value to generate a third sub-modulation signal u in a third modulation signal_{jkz_bat}。

In this embodiment, because the energy storage batteries of the HBIB converter unit adopt double-loop control of the voltage outer loop and the current inner loop, the actual state of charge of each energy storage battery is likely to be different, so the SOC balance control of the energy storage half-bridge converter unit can be realized by adjusting the modulation wave of the half-bridge converter unit in the energy storage half-bridge converter unit. And the energy storage battery is controlled by adopting double-loop control of the voltage outer ring and the current inner ring, so that the energy exchanged between the HMRPC and the load can be automatically compensated when the HMRPC exchanges energy with the load, the energy of the HMRPC is controlled to be stabilized by the energy storage system, the voltage stability of a unit capacitor is maintained, and the normal operation of the system is ensured. And the control strategy has few reference instructions and simple calculation, and does not need to calculate and send a current control instruction to the energy storage unit when the power of the energy storage system is known. It should be noted that, because the energy storage battery adopts the double-ring control of the voltage outer ring and the current inner ring, when the MMC operates normally, the unit voltage is in a fluctuation state, and therefore a unit capacitor voltage dead zone needs to be set to avoid frequent charging and discharging of the energy storage battery.

And 104, controlling a half-bridge converter unit and an energy storage half-bridge converter unit in the energy storage railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal.

Illustratively, as shown in FIG. 12, the first modulation signal u is generated by AC current control_jcThe modulation signals of the upper and lower bridge arm submodules are reversed and respectively connected with a second modulation signal u for circulation control_jccMaking a difference with the first sub-modulation signal u_jklcA second sub-modulation signal u_jkzcSumming, generating a half-bridge switching signal (second control signal) S on the MMC side by carrier phase shift modulation_jkl、S_jkz. Third sub-modulated signal u_{jkz_bat}Generating an energy storage battery side switching signal (first control signal) S by Pulse Width Modulation (PWM)_{jkz_bat}。

The control method of the energy storage railway power regulator is further described by the specific embodiment.

The PSCAD and MATLAB Simulink are used for simulation, the topology of a simulation circuit is shown in figure 1, the secondary side of a V/V transformer is used as a voltage source for simulation, and the voltage of a feeder line is 27.5 kV. The simulation circuit parameters are shown in table 1.

TABLE 1 three-bridge arm energy storage HMRPC simulation parameters

And designing a simulation working condition 1, a simulation step length is 1e-5s, simulation time is 3.5s, 0s starts to start the HMPRC, the same alpha-phase-to-beta-phase transfer power is 8WM, and 0.3s is put into the energy storage system to work. And when 0.3s is needed, removing the total energy of all the converter unit capacitors in the control to control the outer ring, adjusting the compensation current reference instruction at the alternating current side, enabling the power of the load input HMPRC to be 1.6MW, and storing energy through the energy storage system.

The waveform of the compensation current of each phase is shown in fig. 13, the dotted line is a reference command of the compensation current of each phase, the solid line is the compensation current of each phase, and the solid line and the dotted line are basically overlapped, which indicates that the compensation current can follow the given value before and after the energy storage system is put into use. Fig. 14 is a voltage waveform diagram of a cell, and when power is input to the HMRPC by a load, the cell voltage tends to rise, but the capacitance voltage of the HBIB converter cell is stabilized at about 3700V under the outer-loop control of the capacitance voltage, and the cell capacitance voltage of the HB converter cell is also stabilized near the reference value under the equilibrium control strategy.

Fig. 15 is a waveform diagram of charging current of the energy storage battery, when the voltage of the unit capacitor rises to the upper limit of the set voltage dead zone, the energy storage battery is charged under the control of the voltage outer loop of the unit capacitor to maintain the voltage of the capacitor stable. The actual SOC of the HBIB converter unit energy storage battery under the equalization control strategy is shown in fig. 16.

The control method of the energy storage railway power regulator is applied to the energy storage railway power regulator formed by connecting the half-bridge converter unit and the energy storage unit in parallel in the energy storage half-bridge converter unit. Because the energy storage half-bridge converter unit in the energy storage railway power regulator is formed by connecting the half-bridge converter unit and the energy storage unit in parallel, the switching states of the switching devices in the half-bridge converter unit and the energy storage unit can be decoupled, the half-bridge converter unit and the energy storage unit can be controlled independently, and the coupling of the control method of the energy storage railway power regulator is reduced. The number of the energy storage half-bridge converter units is not limited, and the number of the energy storage half-bridge converter units included in the bridge arm sub-modules can be set arbitrarily as long as the number of the converter units included in each bridge arm sub-module is the same. The energy storage railway power regulator control method has the advantages that the energy storage cost is reduced, meanwhile, the flexibility of the topological structure and the control method of the energy storage railway power regulator is improved, the design and the control of the energy storage railway power regulator control method which is simple in control and high in universality are facilitated, and the reliability of the energy storage railway power regulator is improved. In the control method of the energy storage railway power regulator, the current compensation processing is carried out on the load current of each phase of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and a first modulation signal of alternating current control is obtained through calculation; performing circulation control processing based on the obtained compensation current of each phase of the energy storage railway power regulator and the capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit, and calculating to obtain a second modulation signal for circulation control; performing double-loop control on the basis of the capacitor voltage and the acquired actual current and the actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and calculating to obtain a third modulation signal controlled by the unit; and controlling the half-bridge converter unit and the energy storage half-bridge converter unit in the energy storage railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal. The energy storage system formed by all the energy storage units in the energy storage railway power regulator can automatically compensate the energy of the energy storage railway power regulator for compensating the load, the calculation of reference instructions in the control process is reduced, and the control complexity is further reduced.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

The following are embodiments of the apparatus of the invention, reference being made to the corresponding method embodiments described above for details which are not described in detail therein.

Fig. 17 shows an exemplary diagram of a control device of an energy storage railway power regulator according to an embodiment of the present invention, which corresponds to the control method of the energy storage railway power regulator described in the above embodiment. As shown in fig. 17, the apparatus may include: a first processing module 171, a second processing module 172, a third processing module 173, and a control module 174.

The first processing module 171 is configured to perform current compensation processing on load currents of each phase of the electric locomotive load corresponding to the obtained energy storage railway power regulator, and calculate a first modulation signal for controlling the ac current;

the second processing module 172 is configured to perform loop current control processing based on the obtained compensation current of each phase of the energy storage railway power regulator and the obtained capacitor voltage of each half-bridge converter unit and each energy storage half-bridge converter unit in the energy storage railway power regulator, and calculate to obtain a second modulation signal for loop current control;

the third processing module 173 is configured to perform double-loop control based on the capacitor voltage and the acquired actual current and actual state of charge of the energy storage battery of each energy storage half-bridge converter unit, and calculate a third modulation signal for unit control;

a control module 174 for controlling the half-bridge converter units and the energy-storing half-bridge converter units in the energy-storing railway power regulator according to the first modulation signal, the second modulation signal and the third modulation signal.

The control device of the energy storage railway power regulator has the same beneficial effects as the control method of the energy storage railway power regulator in the embodiment.

Fig. 18 is a schematic diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 18, the terminal device 180 of this embodiment includes: a processor 181, a memory 182, and a computer program 183, such as an energy storage railway power conditioner control program, stored in the memory 182 and operable on the processor 181. The processor 181 executes the computer program 403 to implement the steps in the above-mentioned embodiment of the energy storage railway power conditioner control method, such as the steps 101 to 104 shown in fig. 4, and the processor 181 executes the computer program 183 to implement the functions of the modules in the above-mentioned embodiments of the apparatus, such as the modules 171 to 174 shown in fig. 17.

Illustratively, the computer program 183 may be divided into one or more program modules, which are stored in the memory 182 and executed by the processor 181 to carry out the invention. The one or more program modules may be a series of computer program instruction segments capable of performing specific functions for describing the execution of the computer program 183 in the energy storage railway power conditioner control device or terminal equipment 180. For example, the computer program 183 may be divided into a first processing module 171, a second processing module 172, a third processing module 173, and a control unit 174, and specific functions of the modules are shown in fig. 17, which are not described in detail herein.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

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