阅读说明：本技术 一种含多类型储能和新能源接入的能量优化管理方法 (Energy optimization management method containing multi-type energy storage and new energy access ) 是由 柳丹 冀肖彤 梅欣 熊平 肖繁 叶畅 康逸群 邱炜 陈孝明 王伟 胡畔 江克证 于 2021-09-02 设计创作，主要内容包括：本发明提供一种含多类型储能和新能源接入的能量优化管理方法,包括：读取电网运行状态,进行电网正常运行与否的判断；电网正常且母线开关闭合情况下设定风电、光伏、电化学储能、超级电容以及燃料电池储能系统运行状态；电网正常且母线开关断开情况下进入电网恢复运行控制子程序；电网异常情况下,若SOC-(bat)≥SOC-(bat-min)则进入电化学储能系统作为主电源运行控制子程序；电网异常情况下,若SOC-(bat)＜SOC-(bat-min)则进入燃料电池做主电源运行子程序。本发明在电网故障时对所接入的分布式光伏、风电、超级电容、电化学储能系统、以及燃料电池出力进行优化控制,可以最大程度上满足负荷的用电需求,提升供电可靠性。(The invention provides an energy optimization management method containing multi-type energy storage and new energy access, which comprises the following steps: reading the running state of the power grid, and judging whether the power grid runs normally or not; setting the running states of wind power, photovoltaic, electrochemical energy storage, a super capacitor and a fuel cell energy storage system under the condition that the power grid is normal and the bus switch is closed; entering a power grid recovery operation control subprogram under the condition that the power grid is normal and the bus switch is disconnected; if the power grid is abnormal, if the SOC is bat ≥SOC bat_min Entering an electrochemical energy storage system as a main power supply operation control subroutine; if the power grid is abnormal, if the SOC is bat ＜SOC bat_min The fuel cell is entered to perform the main power running subroutine. According to the invention, the output of the connected distributed photovoltaic, wind power, super capacitor, electrochemical energy storage system and fuel cell is optimally controlled when the power grid fails, so that the power demand of the load can be met to the greatest extent, and the power supply reliability is improved.)

1. An energy optimization management method containing multi-type energy storage and new energy access is characterized in that: the method comprises the following steps:

step S1: reading the running state of the power grid, and judging whether the power grid runs normally or not;

step S2: setting the running states of wind power, photovoltaic, electrochemical energy storage, a super capacitor and a fuel cell energy storage system under the condition that the power grid is normal and a bus switch QS1 is closed;

step S3: entering a power grid recovery operation control subprogram under the condition that the power grid is normal and the bus switch QS1 is disconnected;

step S4: if the power grid is abnormal, if the SOC is_bat≥SOC_{bat_min}Entering the electrochemical energy storage system as a main power supply operation control subroutine, wherein the SOC_batIs the current SOC value, SOC, of the electrochemical energy storage system_{bat_min}The lower limit value of the SOC of the electrochemical energy storage system is obtained;

step S5: if the power grid is abnormal, if the SOC is_bat＜SOC_{bat_min}The fuel cell is entered to perform the main power running subroutine.

2. The method as claimed in claim 1, wherein the method comprises the following steps: the step S1 specifically includes: the monitoring platform reads the voltage and the frequency of the AC bus, if the voltage and the frequency satisfy the formula (1), the power grid is in a normal operation state, otherwise, the power grid is abnormal;

U₁∈[U_min，U_max]and f is₁∈[f_min，f_max] (1)

Wherein U is₁And f₁Respectively, the voltage and frequency at sample point 1. U shape_min，U_max，f_min，f_maxThe lower limit, the upper limit, the lower limit and the upper limit of the frequency of the voltage are set according to the load bearing capacity.

3. The method as claimed in claim 1, wherein the method comprises the following steps: in step S3, the power grid operation recovery control subroutine specifically includes:

step 3-1: firstly, reading the on-off state of a grid-connected switch QS6 of the fuel cell energy storage system, directly adjusting the operation mode of the electrochemical energy storage system if the grid-connected switch QS6 is in the off state, so that the electrochemical energy storage system starts to operate synchronously with a power grid, otherwise, adjusting the electrochemical energy storage system to be in the grid-connected operation mode, then disconnecting the grid-connected switch QS6 of the fuel cell energy storage system, and issuing a synchronous operation instruction after the electrochemical energy storage system automatically turns to off-grid load operation so that the electrochemical energy storage system starts to operate synchronously with the power grid;

step 3-2: and judging whether the amplitude and the phase of the output voltage of the electrochemical energy storage system meet the requirement of synchronization with the power grid, if so, closing a bus switch QS1, and ending the power grid recovery operation subprogram.

4. The method as claimed in claim 1, wherein the method comprises the following steps: the operation control subroutine of the electrochemical energy storage system as the main power supply in the step S4 specifically includes:

step 4-1: respectively calculating the output power P of the photovoltaic, the wind power and the load at the current moment according to the voltage and current information read by the branch where the distributed photovoltaic is located, the branch where the distributed wind power is located and the branch where the electrical load is located_pv(t)、P_wind(t)、P_load(t)；

Step 4-2: calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power used by the load, wherein the expression is shown as formula (2), the wind power and the photovoltaic are positive when the power flow direction is towards an alternating current bus, and the electric power used by the load is positive when the current direction is towards the load direction:

△P(t)＝P_pv(t)+P_wind(t)-P_load(t) (2)

step 4-3: if delta P (t) is more than 0, calculating whether wind power and photovoltaic need power-limited operation according to the formula (3), and F_limit(t) is a current time power limit operation zone bit:

in the formula P_{bat_charge_max}(t+1)、P_{sc_charge_max}And (t +1) is the maximum power chargeable in the electrochemical and super-capacitor energy storage systems at the next moment respectively, and the expressions are shown as (4) and (5).

In the formula P_{bat_set}、P_{sc_set}Respectively setting upper limit values and SOC for output power of the electrochemical and super-capacitor energy storage system_bat(t)、SOC_sc(t)、SOC_{bat_max}、SOC_{sc_max}Setting upper limit values for the SOC value and the SOC value of the electrochemical and super-capacitor energy storage system at the current moment respectively;

step 4-4: if F_limitIf (t) is 0, the super capacitor does not need to operate with limited power, and the charging power at the next moment of the super capacitor is as shown in formula (6):

P_{sc_charge}(t+1)＝min[P_{sc_charge_max}(t+1),△P(t)] (6)

and 4-5: if F_limitAnd (t) if 1, the distributed photovoltaic and wind power need to be operated in a limited power mode, the maximum power output value is calculated as shown in a formula (7), the output power upper limits of the wind power and the photovoltaic at the next moment are respectively shown in formulas (8) and (9), and the charging power at the next moment under the super capacitor is shown in a formula (10).

P_{DG_max}(t+1)＝P_{bat_charge_max}(t+1)+P_{sc_charge_max}(t+1)+P_load(t) (7)

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (10)

And 4-5: if delta P (t) is less than or equal to 0, calculating the discharge power value of the super capacitor according to the formula (11):

5. the method as claimed in claim 4, wherein the method comprises the following steps: in step S5, the fuel cell main power supply operation subroutine specifically includes:

step 5-1: closing a grid-connected switch QS6 of a fuel cell energy storage system, and simultaneously calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power used by the load, wherein the expression is shown as a formula (2), the wind power and the photovoltaic are positive when the power flow direction is an alternating current bus, and the electric power used by the load is positive when the current direction is a load direction;

step 5-2: if Δ P (t)>0 then calculates the power limit operation flag F according to step 6-3_limit(t) if F_limitAnd (t) if 0, calculating the charging power of the super capacitor energy storage system at the next moment according to the formula (12):

step 5-3: and further calculating the charging power of the electrochemical energy storage system at the next moment according to the calculated output power of the super capacitor at the next moment, wherein the formula (13) is as follows:

step 5-4: if F_limitIf the t is 1, respectively calculating upper limit values of the distributed photovoltaic output power and the wind power output power according to the steps 6-5, and respectively showing the next-moment charging values of the super capacitor and the electrochemical energy storage system as formulas (14) and (15):

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (14)

P_{bat_charge}(t+1)＝P_{bat_charge_max}(t+1) (15)。

Technical Field

The invention relates to the field of operation control of new energy and multi-type energy storage systems, in particular to an energy optimization management method containing multi-type energy storage and new energy access.

Background

At present, 2851 county-level power grids are total in China and are basic power grid structural units of power distribution networks in communicated villages and towns and superior power transmission networks. A large amount of middle and western counties only rely on single 500kV or 220kV transformer substation power supply, and spatial grid structure is comparatively weak, and the power supply reliability is relatively poor to in case circuit fault repairs the difficulty, and the power off time is longer, and is especially huge to the influence of frontier sentry post.

For solving resident's power consumption problem, install photovoltaic, polymorphic type energy storage in regional electric wire netting usually, but at present mostly be independent operation separately, energy utilization is lower, and is less to the promotion of power supply reliability, especially along with fuel cell's technical maturity constantly promotes its range of application also more and more extensively.

Therefore, a photovoltaic and multi-type energy storage combined operation control algorithm is urgently needed, on one hand, the energy utilization rate is integrally improved, and on the other hand, the power supply quality and the power supply reliability of users are improved.

Disclosure of Invention

The invention provides an energy optimization management method containing multi-type energy storage and new energy access, which improves the energy utilization rate by controlling distributed photovoltaic and wind power to be in a maximum power point tracking operation mode under the normal condition of a power grid, optimally controls the output of the accessed distributed photovoltaic, wind power, super capacitor, electrochemical energy storage system and fuel cell when the power grid fails, meets the power consumption requirement of load to the maximum extent, and improves the power supply reliability.

An energy optimization management method containing multi-type energy storage and new energy access,

step S1: reading the running state of the power grid, and judging whether the power grid runs normally or not;

step S2: setting the running states of wind power, photovoltaic, electrochemical energy storage, a super capacitor and a fuel cell energy storage system under the condition that the power grid is normal and QS1 is closed;

step S3: entering a power grid recovery operation control subroutine under the condition that the power grid is normal and QS1 is disconnected;

step S4: if the power grid is abnormal, if the SOC is_bat≥SOC_{bat_min}Entering the electrochemical energy storage system as a main power supply operation control subroutine, wherein the SOC_batIs the current SOC value, SOC, of the electrochemical energy storage system_{bat_min}The lower limit value of the SOC of the electrochemical energy storage system is obtained;

step S5: under the condition of the abnormal condition of the power grid,if SOC_bat＜SOC_{bat_min}The fuel cell is entered to perform the main power running subroutine.

Further, the step S1 is specifically: the monitoring platform reads the voltage and the frequency of the AC bus, if the voltage and the frequency satisfy the formula (1), the power grid is in a normal operation state, otherwise, the power grid is abnormal;

U₁∈[U_min，U_max]and f is₁∈[f_min，f_max] (1)

Wherein U is₁And f₁Respectively, the voltage and frequency at sample point 1. U shape_min，U_max，f_min，f_maxThe lower limit, the upper limit, the lower limit and the upper limit of the frequency of the voltage are set according to the load bearing capacity.

Further, the power grid operation recovery control subroutine in step S3 specifically includes:

step 3-1: firstly, reading the on-off state of a grid-connected switch QS6 of the fuel cell energy storage system, directly adjusting the operation mode of the electrochemical energy storage system if the grid-connected switch QS6 is in the off state, so that the electrochemical energy storage system starts to operate synchronously with a power grid, otherwise, adjusting the electrochemical energy storage system to be in the grid-connected operation mode, then disconnecting the grid-connected switch QS6 of the fuel cell energy storage system, and issuing a synchronous operation instruction after the electrochemical energy storage system automatically turns to off-grid load operation so that the electrochemical energy storage system starts to operate synchronously with the power grid;

step 3-2: and judging whether the amplitude and the phase of the output voltage of the electrochemical energy storage system meet the requirement of synchronization with the power grid, if so, closing a bus switch QS1, and ending the power grid recovery operation subprogram.

Further, the operation control subroutine of the electrochemical energy storage system as the main power supply in step S4 specifically includes:

step 4-1: respectively calculating the output power P of the photovoltaic, the wind power and the load at the current moment according to the voltage and current information read by the branch where the distributed photovoltaic is located, the branch where the distributed wind power is located and the branch where the electrical load is located_pv(t)、P_wind(t)、P_load(t)；

Step 4-2: calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power for the load, wherein the expression is shown as a formula (2), the wind power and the photovoltaic power flow to an alternating current bus as positive, and the electric power for the load flows to a load direction as positive:

ΔP(t)＝P_pv(t)+P_wind(t)-P_load(t) (2)

step 4-3: if delta P (t) is more than 0, calculating whether wind power and photovoltaic need power-limited operation according to the formula (3), and F_limit(t) is a current time power limit operation zone bit:

in the formula P_{bat_charge_max}(t+1)、P_{sc_charge_max}And (t +1) is the maximum power chargeable in the electrochemical and super-capacitor energy storage systems at the next moment respectively, and the expressions are shown as (4) and (5).

In the formula P_{bat_set}、P_{sc_set}Respectively setting upper limit values and SOC for output power of the electrochemical and super-capacitor energy storage system_bat(t)、SOC_sc(t)、SOC_{bat_max}、SOC_{sc_max}Setting upper limit values for the SOC value and the SOC value of the electrochemical and super-capacitor energy storage system at the current moment respectively;

step 4-4: if F_limitIf (t) is 0, the super capacitor does not need to operate with limited power, and the charging power at the next moment of the super capacitor is as shown in formula (6):

P_{sc_charge}(t+1)＝min[P_{sc_charge_max}(t+1)，ΔP(t)] (6)

and 4-5: if F_limitAnd (t) 1, the distributed photovoltaic and wind power need to be operated in a power limiting mode, the maximum power output value is calculated as shown in a formula (7), and the wind power and the photovoltaic need to be operated in a power limiting modeThe upper limit of the output power at the next moment is respectively shown as formulas (8) and (9), and the charging power at the next moment under the condition of the super capacitor is shown as a formula (10).

P_{DG_max}(t+1)＝P_{bat_charge_max}(t+1)+P_{sc_charge_max}(t+1)+P_load(t) (7)

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (10)

And 4-5: if Δ P (t) ≦ 0, calculating the supercapacitor discharge power value according to equation (11):

further, the fuel cell main power operation subroutine in step S5 specifically includes:

step 5-1: closing a grid-connected switch QS6 of a fuel cell energy storage system, and simultaneously calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power used by the load, wherein the expression is shown as a formula (2), the wind power and the photovoltaic power flow to an alternating current bus as positive, and the electric power used by the load flows to the load direction as positive;

step 5-2: if delta P (t) is more than 0, calculating a power limit operation mark F according to the step 6-3_limit(t) if F_limitAnd (t) if 0, calculating the charging power of the super capacitor energy storage system at the next moment according to the formula (12):

step 5-3: and further calculating the charging power of the electrochemical energy storage system at the next moment according to the calculated output power of the super capacitor at the next moment, wherein the formula (13) is as follows:

step 5-4: if F_limitIf the t is 1, respectively calculating upper limit values of the distributed photovoltaic output power and the wind power output power according to the steps 6-5, and respectively showing the next-moment charging values of the super capacitor and the electrochemical energy storage system as formulas (14) and (15):

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (14)

P_{bat_charge}(t+1)＝P_{bat_charge_max}(t+1) (15)。

the invention provides a self-adaptive energy optimization management method of a combined power supply system accessed by a distributed photovoltaic system, a wind power system, a super-capacitor energy storage system, an electrochemical energy storage system and a fuel cell energy storage system, and the method has the following advantages:

1. the grid-connected or off-grid operation mode of the power supply system can be automatically adjusted according to the voltage information of the grid-connected point of the power supply system obtained by sampling, and the grid-connected operation mode can be automatically recovered after the power supply of the power grid is recovered, so that the uninterrupted power supply of the load can be ensured in the whole switching process;

2. the main power supply setting can be automatically adjusted according to the electrochemical energy storage running state information in the off-grid running state, the electrochemical energy storage system is preferentially used as a main power supply, and the fuel cell energy storage system is used as an auxiliary power supply, so that the reliability of load power supply is further improved by combining the electrochemical energy storage system with the fuel cell energy storage system;

3. through the regulation to electrochemistry energy storage and super capacitor energy storage system, can receive distributed photovoltaic, wind-powered electricity generation's power output by the at utmost, promote energy utilization under the prerequisite of guaranteeing power supply system steady operation.

Drawings

FIG. 1 is a topological diagram of a distributed new energy and multi-type energy storage combined power supply system in the invention;

fig. 2 is a flowchart of an energy optimization management method including multi-type energy storage and new energy access according to an embodiment of the present invention;

FIG. 3 is a detailed flow chart of the present invention;

FIG. 4 is a flow chart of the grid restoration operation of the present invention;

FIG. 5 is a flow chart of the operation of the electrochemical energy storage system of the present invention as a primary power source;

FIG. 6 is a flow chart of the operation of the fuel cell of the present invention as a primary power source;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the invention provides an energy optimization management method including multi-type energy storage and new energy access, which is applied to a distributed new energy and multi-type energy storage combined power supply system (hereinafter referred to as a combined power supply system) shown in fig. 1.

Distributed photovoltaic, distributed wind power, a super-capacitor energy storage system, an electrochemical energy storage system and a fuel cell energy storage system in the distributed new energy and multi-type energy storage combined power supply system are converged into a 380V alternating current bus through respective grid-connected switches (QS2-QS7), the alternating current bus is connected to the low-voltage side of a transformer area through a bus switch QS1, rapid communication channels are arranged between a combined power supply system monitoring platform and each device and switch in the power supply system, the operation information of each device can be acquired in real time, remote control instructions are issued to each grid-connected point switch, meanwhile, the combined power supply system monitoring platform can autonomously acquire voltage and current information of each sampling point in real time, and the integral operation mode of the combined power supply system is divided into a power grid normal operation mode, a power grid abnormal operation mode and a power grid recovery operation mode; the method comprises the following steps:

when the power grid normally operates, the combined power supply system monitoring platform controls and controls the distributed photovoltaic and distributed wind power to be in a maximum power point operation mode, the utilization rate of new energy is improved, the super-capacitor system and the electrochemical energy storage system are in a constant-voltage floating charge operation mode, the electric quantity is kept sufficient, and the fuel cell energy storage system stops operating;

under the condition of power grid abnormity, the joint power supply system monitoring platform firstly cuts off a bus switch QS1 and the power grid, the joint power supply system operates independently, when the electric quantity of the electrochemical energy storage system is sufficient, the electrochemical energy storage system is used as a main power supply to operate, meanwhile, the photovoltaic and wind power output is adjusted according to the electric quantity used by the load, and when the electric quantity of the electrochemical energy storage system is insufficient, the fuel cell energy storage system is started to ensure the electric quantity used by the load.

And after the recovery of the power grid is detected, the combined power supply system monitoring platform adjusts the current main power supply output voltage and frequency, and when the current main power supply output voltage and frequency are consistent with the power grid end, a bus switch QS1 is closed, so that the system is converted into a grid-connected operation mode.

Referring to fig. 2 and fig. 2, the specific implementation steps of an embodiment of the energy optimization management method including multi-type energy storage and new energy access according to the present invention include:

step S1: reading grid information of a grid-connected point, identifying the running state of a power grid according to set conditions, specifically, reading voltage and frequency at a sampling point 1 (namely an alternating current bus) by a monitoring platform, and if the voltage and frequency meet the formula (1), enabling the power grid to be in a normal running state, otherwise, enabling the power grid to be abnormal;

U₁∈[U_min，U_max]and f is₁∈[f_min，f_max] (1)

Wherein U is₁And f₁Respectively, the voltage and frequency at sample point 1. U shape_min，U_max，f_min，f_maxThe lower limit, the upper limit, the lower limit and the upper limit of the frequency of the voltage are set according to the load bearing capacity.

Step S2: and if the power grid is normal and the bus switch QS1 is closed, setting the running states of the wind power system, the photovoltaic system, the electrochemical energy storage system, the super capacitor system and the fuel cell energy storage system.

Specifically, if the grid is judged to be normal, the on-off state information of the bus switch QS1 is further read.

If the bus switch QS1 is in a closed state, a control instruction is issued through the monitoring platform to enable the distributed photovoltaic and wind power to be in a Maximum Power Point Tracking (MPPT) running state, the electrochemical energy storage and super-capacitor energy storage system is in a constant-voltage floating charge running state, and meanwhile, the grid-connected switch QS6 of the fuel cell energy storage system is disconnected, so that the fuel cell energy storage system is separated from the AC bus and is controlled to be in a shutdown state;

step S3: if the power grid is normal and the bus switch QS1 is disconnected, entering a power grid operation recovery control subprogram; if shown in fig. 4, the power grid operation recovery control subroutine specifically includes:

step 3-1: firstly, reading the on-off state of a grid-connected switch QS6 of the fuel cell energy storage system, directly adjusting the operation mode of the electrochemical energy storage system if the grid-connected switch QS6 is in the off state, so that the electrochemical energy storage system starts to operate synchronously with a power grid, otherwise, adjusting the electrochemical energy storage system to be in the grid-connected operation mode, then disconnecting the grid-connected switch QS6 of the fuel cell energy storage system, and issuing a synchronous operation instruction after the electrochemical energy storage system automatically turns to off-grid load operation so that the electrochemical energy storage system starts to operate synchronously with the power grid;

step 3-2: judging whether the amplitude and the phase of the output voltage of the electrochemical energy storage system meet the requirement of synchronization with the power grid or not, if so, closing a bus switch QS1, and ending the power grid recovery operation subprogram;

step S4: if the power grid is abnormal, if the SOC is_bat≥SOC_{bat_min}Entering the electrochemical energy storage system as a main power supply operation control subroutine, wherein the SOC_batIs the current SOC value, SOC, of the electrochemical energy storage system_{bat_min}Is the lower limit value of the SOC of the electrochemical energy storage system.

Specifically, if the power grid is judged to be in an abnormal state, a switch bus switch QS1 and a fuel cell energy storage system grid-connected switch QS6 are disconnected, and the electrochemical energy storage system automatically changes from constant-voltage floating charge operation to off-grid operation; then reading electrochemical energy storage SOC information, if SOC_bat≥SOC_{bat_min}Then the electrochemical energy storage system is entered to be used as a main power supply operation controllerAnd (5) programming.

As shown in fig. 5, the operation control subroutine of the electrochemical energy storage system as a main power supply specifically includes:

step 4-1: respectively calculating the output power P of the photovoltaic, the wind power and the load at the current moment according to the voltage and current information read by the sampling point 2 (the branch where the distributed photovoltaic is located), the sampling point 3 (the branch where the distributed wind power is located) and the sampling point 7 (the branch where the electrical load is located)_pv(t)、P_wind(t)、P_load(t)；

Step 4-2: calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power for the load, wherein the expression is shown as a formula (2), the wind power and the photovoltaic power flow to an alternating current bus as positive, and the electric power for the load flows to a load direction as positive:

ΔP(t)＝P_pv(t)+P_wind(t)-P_load(t) (2)

step 4-3: if delta P (t) is more than 0, calculating whether wind power and photovoltaic need power-limited operation according to the formula (3), and F_limit(t) is a current time power limit operation zone bit:

in the formula P_{bat_charge_max}(t+1)、P_{sc_charge_max}And (t +1) is the maximum power chargeable in the electrochemical and super-capacitor energy storage systems at the next moment respectively, and the expressions are shown as (4) and (5).

In the formula P_{bat_set}、P_{sc_set}Respectively setting upper limit values and SOC for output power of the electrochemical and super-capacitor energy storage system_bat(t)、SOC_sc(t)、SOC_{bat_max}、SOC_{sc_max}Setting upper limit values for the SOC value and the SOC value of the electrochemical and super-capacitor energy storage system at the current moment respectively;

step 4-4: if F_limitIf (t) is 0, the super capacitor does not need to operate with limited power, and the charging power at the next moment of the super capacitor is as shown in formula (6):

P_{sc_charge}(t+1)＝min[P_{sc_charge_max}(t+1)，ΔP(t)] (6)

and 4-5: if F_limitAnd (t) if 1, the distributed photovoltaic and wind power need to be operated in a limited power mode, the maximum power output value is calculated as shown in a formula (7), the output power upper limits of the wind power and the photovoltaic at the next moment are respectively shown in formulas (8) and (9), and the charging power at the next moment under the super capacitor is shown in a formula (10).

P_{DG_max}(t+1)＝P_{bat_charge_max}(t+1)+P_{sc_charge_max}(t+1)+P_load(t) (7)

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (10)

And 4-5: if Δ P (t) ≦ 0, calculating the supercapacitor discharge power value according to equation (11):

step S5: if the power grid is abnormal, if the SOC is_bat＜SOC_{bat_min}The fuel cell is entered to perform the main power running subroutine.

Specifically, if SOC_bat＜SOC_{bat_min}Starting the fuel cell energy storage system to operate, and when the fuel cell energy storage system operates stably, the monitoring platform sends a synchronous operation control instruction to the electrochemical energy storage system; detection ofAnd if the output voltage of the electrochemical energy storage system meets the requirement of the fuel cell energy storage system in the same period, entering the fuel cell to be used as a main power supply operation subprogram.

As shown in fig. 6, the fuel cell main power operation sub-routine specifically includes:

step 5-1: closing a grid-connected switch QS6 of a fuel cell energy storage system, and simultaneously calculating a difference value delta P (t) between the output power of the distributed new energy and the electric power used by the load, wherein the expression is shown as a formula (2), the wind power and the photovoltaic power flow to an alternating current bus as positive, and the electric power used by the load flows to the load direction as positive;

step 5-2: if delta P (t) is more than 0, calculating a power limit operation mark F according to the step 6-3_limit(t) if F_limitAnd (t) if 0, calculating the charging power of the super capacitor energy storage system at the next moment according to the formula (12):

step 5-3: and further calculating the charging power of the electrochemical energy storage system at the next moment according to the calculated output power of the super capacitor at the next moment, wherein the formula (13) is as follows:

step 5-4: if F_limitIf the t is 1, respectively calculating upper limit values of the distributed photovoltaic output power and the wind power output power according to the steps 6-5, and respectively showing the next-moment charging values of the super capacitor and the electrochemical energy storage system as formulas (14) and (15):

P_{sc_charge}(t+1)＝P_{sc_charge_max}(t+1) (14)

P_{bat_charge}(t+1)＝P_{bat_charge_max}(t+1) (15)。

the invention provides a self-adaptive energy optimization management method of a combined power supply system accessed by a distributed photovoltaic system, a wind power system, a super-capacitor energy storage system, an electrochemical energy storage system and a fuel cell energy storage system, and the method has the following advantages:

1. the grid-connected or off-grid operation mode of the power supply system can be automatically adjusted according to the voltage information of the grid-connected point of the power supply system obtained by sampling, and the grid-connected operation mode can be automatically recovered after the power supply of the power grid is recovered, so that the uninterrupted power supply of the load can be ensured in the whole switching process;

2. the main power supply setting can be automatically adjusted according to the electrochemical energy storage running state information in the off-grid running state, the electrochemical energy storage system is preferentially used as a main power supply, and the fuel cell energy storage system is used as an auxiliary power supply, so that the reliability of load power supply is further improved by combining the electrochemical energy storage system with the fuel cell energy storage system;

3. through the regulation to electrochemistry energy storage and super capacitor energy storage system, can receive distributed photovoltaic, wind-powered electricity generation's power output by the at utmost, promote energy utilization under the prerequisite of guaranteeing power supply system steady operation.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.