阅读说明：本技术 一种双绕组永磁电机起动发电系统及其容错控制方法 (Double-winding permanent magnet motor starting power generation system and fault-tolerant control method thereof ) 是由 张卓然 黄健 韩建斌 石珩 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种双绕组永磁电机起动发电系统及其容错控制方法,属于起动发电技术领域。该双绕组永磁电机起动发电系统主要包括：双绕组永磁电机、两套变换器、两套直流接触器、动力电池和电气负载；该双绕组永磁电机起动发电容错控制方法,发动机起动时,两套变换器接收相同的起动指令,在正常状态下,每套绕组输出一半的起动转矩指令值,从而带动发动机起动。在发电状态正常模式下,永磁电机两套绕组输出相同的发电转矩,从而满足直流侧输出功率的需求。本发明能够实现发动机的可靠起动以及稳定的功率输出,发电控制简单,并且在一套绕组或者变换器故障时发电系统仍能输出一定的功率,可靠性较高。(The invention discloses a double-winding permanent magnet motor starting power generation system and a fault-tolerant control method thereof, and belongs to the technical field of starting power generation. The double-winding permanent magnet motor starting power generation system mainly comprises: the system comprises a double-winding permanent magnet motor, two sets of converters, two sets of direct current contactors, a power battery and an electrical load; according to the fault-tolerant control method for starting and generating the double-winding permanent magnet motor, when an engine is started, two sets of converters receive the same starting instruction, and each set of windings outputs half of starting torque instruction values under a normal state, so that the engine is driven to start. Under the normal mode of the power generation state, two sets of windings of the permanent magnet motor output the same power generation torque, so that the requirement of the output power of the direct current side is met. The invention can realize the reliable starting and stable power output of the engine, has simple power generation control, can still output certain power when one set of winding or converter fails, and has higher reliability.)

1. A double-winding permanent magnet motor starting power generation system is characterized by mainly comprising: the system comprises a double-winding permanent magnet motor, two sets of converters, two sets of direct current contactors, a power battery and an electrical load;

the stator winding of the double-winding permanent magnet motor adopts a star connection mode and is provided with two independent neutral points; the power battery outputs energy in the starting process of the engine, and absorbs electric energy output by the motor and provides energy for an electrical load in the power generation process;

the AC sides of the two sets of converters are respectively connected with the output ends of the two sets of windings of the double-winding permanent magnet motor, the neutral points of the two sets of windings of the double-winding permanent magnet motor are mutually decoupled, the anodes of the DC sides of the two sets of converters are respectively connected to the anode of the power battery through a DC contactor, the cathodes of the DC sides of the two sets of converters are connected to the cathode of the power battery, and the two sets of converters are communicated by adopting a CAN bus to monitor the mutual state;

the upper computer sends control instructions of the motor, such as torque or rotating speed, to the two sets of converter digital signal processing units through the CAN bus, and meanwhile, the two sets of converter digital signal processing units send motor state information to the upper computer through the CAN bus.

2. The dual winding permanent magnet motor start-up power generation system of claim 1, further comprising,

the rotary transformer is used for feeding back a motor rotor position signal;

the current sensor is used for detecting the current in the two sets of windings in real time;

the voltage sensor is used for detecting the voltage of two ends of the power battery in real time;

the thermistor is used for detecting the temperature of the motor armature winding in real time;

each set of converter consists of a three-phase bridge arm, a direct-current filter capacitor, a sampling conditioning circuit, a decoding circuit, a driving amplification isolation circuit and a digital signal processing unit, wherein the three-phase bridge arm is formed by connecting six switching tubes with anti-parallel diodes in parallel in pairs;

the rotary transformer outputs the position information of the motor rotor, the position angle of the permanent magnet motor rotor is obtained through calculation of a decoding circuit, and the position angle of the rotor is sent to the digital signal processing unit; the detected current signal, voltage signal and temperature signal are sent to the digital signal processing unit through the sampling conditioning circuit, the digital signal processing unit carries out vector control operation according to the detected current signal, voltage signal, motor rotor position angle and control instruction sent by the upper computer, the calculated PWM signal is output to the three-phase bridge arm through the driving amplification isolation circuit, and the action of the switching tube is controlled, so that the permanent magnet motor runs according to the control instruction.

3. The dual-winding permanent magnet motor starting power generation system of claim 2, wherein the current sensor uses a hall current sensor to detect the current in the two sets of windings; the thermistor adopts a PT100 thermistor to detect the temperature of the motor winding.

4. A fault-tolerant control method for starting and generating of a double-winding permanent magnet motor is based on the system and comprises the following steps:

1) in the starting process, the two sets of converters receive a starting instruction from an upper computer through a CAN bus, set a starting torque instruction value, and calculate compensation torque according to speed limit control to obtain an actual starting torque instruction; then, a torque current instruction is obtained according to the actual starting torque instruction and a torque ammeter, and the two sets of windings of the motor are enabled to output 1/2 actual starting torque instructions through current closed-loop control;

in the starting process, winding current is detected, if one set of windings has overcurrent faults, PWM signal output of a converter connected with a fault phase winding is blocked, and the other set of windings outputs all actual starting torque instructions, so that the engine is ensured to be started reliably;

2) in the power generation process, the two sets of converters receive a power generation torque instruction from an upper computer through a CAN bus, calculate compensation torque according to voltage limiting control to obtain an actual power generation torque instruction, then look up a table according to actual power generation torque and a torque ammeter to obtain a power generation torque current instruction, and enable each set of windings of the motor to output 1/2 actual power generation torque instructions through current closed-loop control;

when a set of windings or converters are detected to have faults, such as overcurrent faults, overspeed faults or IGBT (insulated gate bipolar translator) overtemperature faults, the torque current instruction value of the corresponding winding is zero, PWM (pulse-width modulation) output of the corresponding converter is blocked, and then the corresponding direct current contactor is controlled to disconnect the corresponding converter and a power battery, so that the faults are prevented from spreading to normal windings and the converter; for the other normal set of windings, when the actual generating torque instruction value is smaller than the maximum output torque of the single set of windings, the windings output the actual generating torque instruction; when the actual generating torque instruction value is larger than the maximum output torque of the single set of winding, the winding outputs the maximum torque;

when detecting that the temperature of one set of windings is overhigh, reducing the invention torque command of the set of windings to 1/4 of the actual power generation torque command, and outputting 3/4 of the actual power generation torque command by the other set of normal windings;

when both sets of windings detect an excessive temperature, the command torque of both sets of windings is reduced to 1/4 of the actual generation torque command, and in this state, the output power of the system is half of that in the normal state.

Technical Field

The invention relates to a starting power generation system, in particular to a double-winding permanent magnet motor starting power generation system and a fault-tolerant control method thereof, and belongs to the technical field of starting power generation.

Background

The electric energy of the multi-electric airplane mainly comes from a generator set driven by an engine, and the conversion and the output of the electric energy are realized by a generator and a control system thereof. Meanwhile, in order to realize the integration of the system, improve the power density and ensure the effective output of electric energy in a limited space, the generator is required to have two functions of electric operation and power generation to form the integration of starting and power generation, thereby replacing the conventional starter and generator and providing higher requirements for the starting generator and a control system thereof. On one hand, the starter generator is required to be capable of working in an electric state to drive the engine to an idle state by constant torque or constant power, on the other hand, the starter generator system is required to be capable of working in a power generation state to output constant direct-current voltage to provide required electric energy for the whole electrical load, and meanwhile, the whole power generation system is required to have high reliability and fault tolerance. Therefore, research on a starting power generation system and a fault-tolerant control method thereof is an important issue in the field of aviation.

The permanent magnet motor has the advantages of high power density and high efficiency and is widely applied to the field of electric automobiles, and meanwhile, the permanent magnet motor also has great application potential in the field of aviation starting and power generation. Compared with the common permanent magnet motor, the double-winding permanent magnet motor has one more set of armature windings, the two sets of armature windings can be independently controlled by two sets of converters, the power required to be output by each set of windings is relatively reduced, and the current stress of the converters is reduced; when one set of winding or the converter fails completely, the other set of normal winding and converter can still output certain power, so that the double-winding permanent magnet starting generator has the advantages of flexible control, high reliability and strong fault-tolerant capability, and has good application prospect in the fields of aviation main power supplies, vehicle-mounted power generation and ship power generation.

At present, the research on the dual-winding permanent magnet motor mainly focuses on electric and fault-tolerant control, including fault-tolerant control of open circuit and short circuit of the motor winding. Patent 201711364314.X proposes a demagnetization protection method for a permanent magnet motor based on a double-winding permanent magnet motor, which actively injects a current to generate a magnetic field in a direction opposite to that of a short-circuit current through a non-fault armature winding to counteract a demagnetization magnetic field generated by the fault winding due to the short-circuit current. However, for the dual-winding permanent magnet motor starting power generation system, the corresponding starting power generation control strategy and fault-tolerant control strategy are less researched, and particularly the control strategy and the fault-tolerant control method under the power generation running state are less researched.

Disclosure of Invention

The invention provides a double-winding permanent magnet motor starting and generating system with high reliability and redundancy and a fault-tolerant control method thereof, aiming at overcoming the problem of low reliability of a permanent magnet motor starting and generating system in the prior art.

The specific technical scheme of the invention is as follows:

a double-winding permanent magnet motor starting power generation system mainly comprises: the system comprises a double-winding permanent magnet motor, two sets of converters, two sets of direct current contactors, a power battery and an electrical load;

the stator winding of the double-winding permanent magnet motor adopts a star connection mode and is provided with two independent neutral points; the power battery outputs energy in the starting process of the engine, and absorbs electric energy output by the motor and provides energy for an electrical load in the power generation process;

the AC sides of the two sets of converters are respectively connected with the output ends of the two sets of windings of the double-winding permanent magnet motor, the neutral points of the two sets of windings of the double-winding permanent magnet motor are mutually decoupled, the anodes of the DC sides of the two sets of converters are respectively connected to the anode of the power battery through a DC contactor, the cathodes of the DC sides of the two sets of converters are connected to the cathode of the power battery, and the two sets of converters are communicated by adopting a CAN bus to monitor the mutual state. The upper computer sends control instructions of the motor, such as torque or rotating speed, to the two sets of converter digital signal processing units through the CAN bus, and meanwhile, the two sets of converter digital signal processing units send motor state information to the upper computer through the CAN bus.

Furthermore, the double-winding permanent magnet motor starting and generating system also comprises,

the rotary transformer is used for feeding back a motor rotor position signal;

the current sensor is used for detecting the current in the two sets of windings in real time;

the voltage sensor is used for detecting the voltage of two ends of the power battery in real time;

the thermistor is used for detecting the temperature of the motor armature winding in real time;

each set of converter consists of a three-phase bridge arm, a direct-current filter capacitor, a sampling conditioning circuit, a decoding circuit, a driving amplification isolation circuit and a digital signal processing unit, wherein the three-phase bridge arm is formed by connecting six switching tubes with anti-parallel diodes in parallel in pairs;

the rotary transformer outputs the position information of the motor rotor, the position angle of the permanent magnet motor rotor is obtained through calculation of a decoding circuit, and the position angle of the rotor is sent to the digital signal processing unit; the detected current signal, voltage signal and temperature signal are sent to the digital signal processing unit through the sampling conditioning circuit, the digital signal processing unit carries out vector control operation according to the detected current signal, voltage signal, motor rotor position angle and control instruction sent by the upper computer, the calculated PWM signal is output to the three-phase bridge arm through the driving amplification isolation circuit, and the action of the switching tube is controlled, so that the permanent magnet motor runs according to the control instruction.

Furthermore, the current sensor adopts a Hall current sensor to detect the current in the two sets of windings; the thermistor adopts a PT100 thermistor to detect the temperature of the motor winding.

When one set of winding or converter fails and cannot work normally, the digital signal processing unit outputs a corresponding control signal to control the direct current contactor of the path to be disconnected, so that the connection between the failed phase winding or converter and the direct current bus is disconnected, the influence of the fault on the direct current side voltage is avoided, the output power of the power generation system is provided by one set of winding and converter, and the output capacity of the system is reduced.

The invention discloses a fault-tolerant control method for starting and generating a double-winding permanent magnet motor, which comprises the following steps of:

1) in the starting process, the two sets of converters receive a starting instruction from an upper computer through a CAN bus, set a starting torque instruction value, and calculate compensation torque according to speed limit control to obtain an actual starting torque instruction; then, a torque current instruction is obtained according to the actual starting torque instruction and a torque ammeter, and the two sets of windings of the motor are enabled to output 1/2 actual starting torque instructions through current closed-loop control;

in the starting process, winding current is detected, if one set of windings has overcurrent faults, PWM signal output of a converter connected with the fault phase winding is blocked, and the other set of windings outputs all actual starting torque instructions, so that the engine is ensured to be started reliably.

(the effect of speed limit control is that when the rotating speed of the motor exceeds the self-sustaining rotating speed, a compensation torque is output through the speed limit control, the compensation torque reduces the instruction torque of the motor, so that the output torque of each set of windings is reduced, the rotating speed of the motor is reduced, if the rotating speed of the motor is lower than the self-sustaining rotating speed, the compensation torque is zero, and the reliable starting of the engine can be realized through the speed limit strategy.)

2) In the power generation process, the two sets of converters receive a power generation torque instruction from an upper computer through a CAN bus, calculate compensation torque according to voltage limiting control to obtain an actual power generation torque instruction, then look up a table according to actual power generation torque and a torque ammeter to obtain a power generation torque current instruction, and enable each set of windings of the motor to output 1/2 actual power generation torque instructions through current closed-loop control.

(the effect of the voltage limiting control is to output a compensation torque through the voltage limiting control when the voltage on the direct current side is higher than the maximum voltage which can be borne by the power battery, and the compensation torque can reduce the command torque, thereby reducing the output torque of each set of windings and preventing the voltage on the direct current side from being overhigh.)

When a set of windings or converters are detected to have faults, such as overcurrent faults, overspeed faults or IGBT (insulated gate bipolar translator) overtemperature faults, the torque current instruction value of the corresponding winding is zero, PWM (pulse-width modulation) output of the corresponding converter is blocked, and then the corresponding direct current contactor is controlled to disconnect the corresponding converter and a power battery, so that the faults are prevented from spreading to normal windings and the converter; for the other normal set of windings, when the actual generating torque instruction value is smaller than the maximum output torque of the single set of windings, the windings output the actual generating torque instruction; when the actual generating torque instruction value is larger than the maximum output torque of the single set of winding, the winding outputs the maximum torque;

when the detected temperature of one set of windings is overhigh, the invention torque command of the set of windings is reduced to 1/4 of the actual power generation torque command, the other set of normal windings outputs 3/4 of the actual power generation torque command, and in the state, the maximum output power of the power generation system is reduced.

When both sets of windings detect an excessive temperature, the command torque of both sets of windings is reduced to 1/4 of the actual generation torque command, and in this state, the output power of the system is half of that in the normal state.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the double-winding permanent magnet motor starting power generation system, when one set of winding or the converter fails completely, energy required by an electrical load is provided by the other set of normal winding and converter, the redundancy of the power generation system is high, and the fault cannot influence the normal winding and converter.

2. The double-winding permanent magnet motor starting power generation system has the advantages that the direct current side is connected in parallel without adopting a current sharing algorithm, the reason is that a double-winding structure is adopted in the same stator, the difference between the two windings is small, in the power generation state, the permanent magnet motor works in a torque mode, a voltage outer ring is not arranged, the received power generation torque is shared equally at the moment, half of torque is generated by the two windings respectively, the phase current in the two windings is basically the same, and the bus current balance can be realized.

3. According to the double-winding permanent magnet motor starting power generation system, under the condition that one set of winding is overheated, the output power of the set of winding is limited, the reduced power part is output by the other set of normal winding, and the output power of the power generation system can be kept unchanged.

Drawings

FIG. 1 is a block diagram of a dual-winding permanent magnet motor starting power generation system (also referred to as abstract figure);

FIG. 2 is a schematic diagram of a permanent magnet motor starting and power generation control;

FIG. 3 is a flowchart of start control;

FIG. 4 is a functional block diagram of a start control;

FIG. 5 is a schematic block diagram of speed limit control;

FIG. 6 is a power generation control flow diagram;

FIG. 7 is a schematic block diagram of power generation control;

FIG. 8 is a schematic block diagram of the parallel control of the dual windings in the normal state;

FIG. 9 is a block diagram of the fault tolerant control scheme for complete failure of a set of windings or converters;

FIG. 10 is a schematic block diagram of fault tolerant control when a set of windings are overheated;

FIG. 11 is a fault-tolerant control schematic diagram of two sets of windings over-heating;

the reference numbers in the figures illustrate: t is₁、T₂、T₃、T₄、T₅、T₆Is a switching tube with an antiparallel diode, C₁Is a filter capacitor on the DC side of the converter 1, C₂Is the DC side filter capacitor, T, of the converter 2₁～T₆Switching tube drive signal, T, for the output of the converter 1₇～T₁₂Switching tube drive signal, H, for the output of the converter 2_1～3Three current Hall sensors for the first set of windings, H_4～6Three current Hall sensors for the second set of windings, θ₁And theta₂The position angle i of the motor rotor is obtained by decoding and calculating two sets of converters respectively₁Is a three-phase current of the first set of windings i₂Is a three-phase current of the second set of windings u_dc1、i_dc1A DC side voltage and a DC side current, u, of the converter 1_dc2、i_dc2The dc side voltage and the dc side current of the converter 2, respectively. n is_fdbFor feedback of rotational speed, i_sqrefFor starting the torque current command, i_gqrefFor the generation torque current command, i_qrefAs a torque current command value, i_drefIs an exciting current command value, i_qfdbAs a torque current feedback value, i_dfdbFor the value of the excitation current feedback, U_d、U_qThe d-axis voltage command value and the q-axis voltage command value are respectively set. T is_emp1And T_emp2Are respectively two setsThe temperature of the winding. T is_startFor starting torque command value, T_srefFor actual starting torque, T_scmpCompensating torque output for speed-limiting control, n_limitFor engine idle speed, i_sqref1And i_sqref2The starting torque current instruction values of the two sets of windings are respectively. T is_geneAs a power generation torque command value, T_grefFor actual generating torque, T_gcmpCompensating torque, T, for limiting the output_gref1And T_gref2Actual generation torques, i, of two sets of windings, respectively_gqref1And i_gqref2And the generated torque current instruction values of the two sets of windings are respectively.

Detailed Description

The technical scheme of the invention is explained in detail in the following with the accompanying drawings: