阅读说明：本技术 一种大功率开关磁阻电机控制电路及其控制方法 (Control circuit and control method for high-power switched reluctance motor ) 是由 张亚楠 李龙春 姜宇 管毅 文佳慧 于 2021-09-01 设计创作，主要内容包括：本申请属于航空电机控制技术领域,特别涉及一种大功率开关磁阻电机控制电路及其控制方法,该控制电路包括两个相同的单三相不对称半桥拓扑,以及输入电容C1、发电滤波电容C2以及二极管D3；其中,上管功率开关管的集电极、输入电容C1的正端、二极管D3的阴极汇流至起动机电压输入正端；上管二极管的阴极,发电滤波电容C2的正端、二极管D3的阳极汇流至发电电压输出正端；下管功率开关管的发射极、下管二极管的阳极、输入电容C1的负端、发电滤波电容C2的负端汇流后分两个接线端子分别连接至发电电压输出负端、起动机电压输入负端。本申请在不增加功率器件的应力水平的情况下,减少了功率器件数量,提高了系统功重比和可靠性。(The control circuit comprises two identical single three-phase asymmetric half-bridge topologies, an input capacitor C1, a power generation filter capacitor C2 and a diode D3; the collector of the upper tube power switch tube, the positive end of the input capacitor C1 and the cathode of the diode D3 are converged to the positive end of the voltage input of the starter; the cathode of the upper tube diode, the positive end of the power generation filter capacitor C2 and the anode of the diode D3 are converged to the positive end of the power generation voltage output; an emitter of the lower tube power switch tube, an anode of the lower tube diode, a negative end of the input capacitor C1 and a negative end of the power generation filter capacitor C2 are converged and then divided into two wiring terminals which are respectively connected to a power generation voltage output negative end and a starter voltage input negative end. According to the power device and the power device control method, under the condition that the stress level of the power device is not increased, the number of the power devices is reduced, and the power-to-weight ratio and the reliability of a system are improved.)

1. A high-power switched reluctance motor control circuit comprises two identical single three-phase asymmetric half-bridge topologies, wherein each phase asymmetric half-bridge topology comprises a positive phase and a negative phase, the positive phase comprises an upper tube power switch tube and a lower tube diode, and the negative phase comprises a lower tube power switch tube and an upper tube diode, and is characterized by further comprising an input capacitor C1, a power generation filter capacitor C2 and a diode D3; wherein the content of the first and second substances,

the collector of the upper tube power switching tube of each phase of asymmetric half-bridge topology, the positive end of an input capacitor C1 and the cathode of a diode D3 are converged to the positive end of the voltage input of the starter;

the cathode of the upper tube diode, the positive end of the power generation filter capacitor C2 and the anode of the diode D3 of each phase of asymmetric half-bridge topology are converged to the positive end of the power generation voltage output;

an emitter of a lower tube power switch tube, an anode of a lower tube diode, a negative end of an input capacitor C1 and a negative end of a power generation filter capacitor C2 of each phase of asymmetric half-bridge topology are converged and then divided into two wiring terminals which are respectively connected to a power generation voltage output negative end and a starter voltage input negative end.

2. The control circuit of claim 1, wherein the control circuit has a first mode, the first mode is an excitation mode, and when the control circuit is in the first mode, the upper tube power switch and the lower tube power switch of the two single-three-phase asymmetric half-bridge topologies are controlled to output a high level.

3. The high power switched reluctance machine control circuit according to claim 1, wherein said control circuit has a second mode, said second mode being a freewheeling mode, when said control circuit is in said second mode, a first upper tube power switch tube of said single three-phase asymmetric half-bridge topology freewheels to be controlled to output a high level, and a second lower tube power switch tube of said single three-phase asymmetric half-bridge topology freewheels to be controlled to output a high level.

4. The high power switched reluctance machine control circuit according to claim 1, wherein said control circuit has a third mode, said third mode is a freewheeling mode, when said control circuit is in the third mode, a first of said lower tube power switch tubes of said single three-phase asymmetric half-bridge topology freewheels to be controlled to output a high level, and a second of said upper tube power switch tubes of said single three-phase asymmetric half-bridge topology freewheels to be controlled to output a high level.

5. The control circuit of claim 1, wherein the control circuit has a fourth mode, the third mode is a negative-voltage demagnetization mode, and when the control circuit is in the fourth mode, both the upper tube power switching tube and the lower tube power switching tube of the single three-phase asymmetric half-bridge topology are turned off.

6. A control method of a control circuit of a high power switched reluctance motor, which employs the control circuit of the high power switched reluctance motor according to claim 1, the method comprising:

step 1, the control circuit of the high-power switched reluctance motor forms three control modes by controlling the opening and closing of the upper tube power switching tube and the lower tube power switching tube of the two single-three-phase asymmetric half-bridge topologies, wherein the first mode is an excitation mode, the second mode is an upper tube follow current mode, the third mode is a lower tube follow current mode, the upper tube power switching tube and the lower tube power switching tube of the two asymmetric half-bridge topologies in the excitation mode both output high levels, the upper tube follow current mode refers to the high level output by the upper tube power switching tube of one asymmetric half-bridge topology, and the lower tube follow current mode refers to the high level output by the upper tube power switching tube of the other asymmetric half-bridge topology;

and step S2, controlling the on-off of each upper tube power switch tube and each lower tube power switch tube of the high-power switched reluctance motor control circuit by adopting a cyclic control mode of alternating control of a first mode, a second mode, the first mode and a third mode.

7. The control method of the high power switched reluctance motor control circuit according to claim 6, wherein the cyclic control manner of the alternating control includes:

step S21, when the position angle theta of the motor rotor is in the A-phase conduction interval, the theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onAt the beginning of time, pairThe falling edge of the PWM modulation waveform S2 counts from 0;

step S22, when the PWM modulation waveform S2 detects a rising edge, G11, G12, G13 and G13 output a high level, where a first upper tube power switch of the single three-phase asymmetric half-bridge topology has a first control signal G11, a first lower tube power switch of the single three-phase asymmetric half-bridge topology has a second control signal G12, a second upper tube power switch of the single three-phase asymmetric half-bridge topology has a third control signal G13, and a second lower tube power switch of the single three-phase asymmetric half-bridge topology has a fourth control signal G13;

step S23, when the PWM modulation waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal goes low and the G12 signal remains.

Technical Field

The application belongs to the technical field of aviation motor control, and particularly relates to a control circuit and a control method for a high-power switched reluctance motor.

Background

For the switched reluctance starting/generating power topology, many studies are made at home and abroad, but the small power level is mainly focused on, and the single three-phase asymmetric half-bridge power topology is more, and the topology is shown in fig. 1.

In fig. 1, the bridge arm of each phase may be composed of a controllable power transistor and a diode independently or an asymmetric half-bridge module, and independent control of the three-phase winding of the switched reluctance motor is further achieved by controlling the power transistor in each phase of the asymmetric half-bridge circuit. In the topology, the on-off control of the switch tube in each phase of asymmetric circuit can be divided into four working modes: the device comprises a positive-pressure excitation mode, a zero-pressure upper tube follow current mode, a zero-pressure lower tube follow current mode and a negative-pressure demagnetization mode.

In the conventional control strategy, taking phase a as an example for explanation, when the position angle θ of the motor rotor is in the phase a conduction interval, that is, θ is satisfied_on≤θ≤θ_offWhen the power switch tube VT11 and the power switch tube VT12 are controlled to be switched on or switched off, so that the phase A works in a positive-pressure excitation mode or a zero-pressure upper tube follow current mode or a zero-pressure lower tube follow current mode; and outside the phase angle A conduction interval, the power switching tubes VT11 and VT12 are kept in a turn-off state, so that the phase A works in a negative voltage demagnetization mode. The timing diagram of the control signals is shown in fig. 2, in which S1 is a waveform of the position angle θ of the a-phase winding and the relative position of the conduction interval, S2 is a PWM modulation waveform, G11 is a control signal of the switching transistor VT11, and G12 is a control signal of the switching transistor VT 12.

In fig. 2, the first stage is a positive-voltage excitation mode, and the switching tubes VT11 and VT12 are turned on; the second phase is a zero-voltage tube-descending follow current mode, the switching tube VT12 is switched on, the VT11 is switched off, the phase A current I flows through VT12 and D11, and the current is the phase current I; the third stage is a positive-pressure excitation mode, and the switching tubes VT11 and VT12 are conducted; and the fourth stage is zero-voltage tube-on freewheeling, the switching tube VT11 is switched on, the VT12 is switched off, the A-phase current I freewheels through VT11, D12 and D3, and the current is the phase current I.

The control signals G11 and G12 of the switch tubes VT11 and VT12 through the analysis simultaneously satisfy the following logical relationship:

when the position angle theta of the motor rotor is in the A-phase conduction interval, theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onFrom time to time, the falling edge of the PWM modulation waveform S2 is counted from 0.

When the PWM modulation waveform S2 detects a rising edge, G11, G12 output a high level;

when the PWM waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal outputs low level, and the G12 signal is kept;

control signals G21 and G22 of the switch tubes VT21 and VT22 also meet the logical relation when the position angle theta of the motor rotor is in the B-phase conduction interval; the control signals G31 and G32 of the switch tubes VT31 and VT32 also satisfy the logical relation of the third step when the position angle theta of the motor rotor is in the C-phase conduction interval.

With the development of multi-electric aircraft, high-power starting/generating systems have become necessary. However, due to the limitation of the power grade of the power device at the present stage, the single three-phase asymmetric half-bridge power topology cannot meet the requirement of a high-power starting/generating system.

Therefore, two single three-phase asymmetric half-bridge power topologies can be connected in parallel to form a dual three-phase asymmetric half-bridge power topology, as shown in fig. 3.

In the traditional double three-phase asymmetric half-bridge power topology, the two single three-phase asymmetric half-bridge power topologies have no coupling phenomenon, and the traditional control strategy aiming at the single three-phase asymmetric half-bridge topology can be adopted. And the phase difference between the corresponding phases of the two single three-phase asymmetric half bridges can be adjusted, and the phase difference between the corresponding phases of the two single three-phase asymmetric half bridges is 0 for analysis. Fig. 4 is a control timing chart. Taking phase a1 and phase a2 as an example, the control signals G11, G12, G13 and G14 of the switching tubes VT11, VT12, VT13 and VT14 in the double three-phase asymmetric half bridge need to satisfy the following logic relationship and formula 1 at the same time:

when the position angle theta of the motor rotor is in the A-phase conduction interval, theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onFrom time to time, the falling edge of the PWM modulation waveform S2 is counted from 0.

When the PWM modulation waveform S2 detects a rising edge, G11, G12 output a high level;

when the PWM waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal outputs low level, and the G12 signal is kept; g13 is the same as the G11 control strategy, and G14 is the same as the G12 control strategy.

Control signals G21, G22, G23 and G24 of switching tubes VT21, VT22, VT23 and VT24 also meet the third logical relation and the formula 1 when the position angle theta of the motor rotor is in a B-phase conduction interval; control signals G31, G32, G33 and G34 of the switching tubes VT31, VT32, VT33 and VT34 also meet the third logical relation and the formula 1 when the position angle theta of the motor rotor is in the C-phase conduction interval.

In fig. 4, the first phase is an excitation mode, and the switching tubes VT11, VT12, VT13 and VT14 are turned on; the second stage is a low tube follow current mode, switching tubes VT12 and VT14 are switched on, VT11 and VT13 are switched off, the phase current on the A1 winding continues current through VT12 and D11, and the phase current on the A2 winding continues current through VT14 and D13; the third phase is an excitation mode, and the switching tubes VT11, VT12, VT13 and VT14 are conducted; the fourth stage is upper tube freewheeling, switching tubes VT11 and VT13 are switched on, VT12 and VT14 are switched off, the phase current on the winding of A1 freewheels through VT11, D12 and D3, and the phase current on the winding of A2 freewheels through VT13, D14 and D4.

Although the traditional double three-phase asymmetric half-bridge power topology meets the high-power requirement under the level of the existing power device, the traditional double three-phase asymmetric half-bridge power topology still has some defects: the traditional double three-phase asymmetric half-bridge power topology increases the number of power devices, increases the volume and weight of the system and reduces the power-to-weight ratio of the system;

therefore, under the condition of meeting the requirements of high power and not reducing the power grade, the invention aims to reduce the number of power topological devices, reduce the volume weight of the power devices and improve the power-to-weight ratio of a system by optimizing a control strategy.

Disclosure of Invention

In order to solve the technical problems, the application provides a control strategy for a switched reluctance motor in an aviation high-voltage direct-current switched reluctance high-power starting/generating system, and under the condition of meeting the requirements of high power and not reducing the power grade, the number of power topological devices is reduced and the volume weight of the power devices is reduced by optimizing the control strategy, so that the power-to-weight ratio of the system is improved, a foundation is laid for the application of a subsequent switched reluctance high-power starting/generating system, and meanwhile, a reference is provided for other similar systems.

The first aspect of the application provides a high-power switched reluctance motor control circuit, which comprises two identical single-three-phase asymmetric half-bridge topologies, wherein each phase asymmetric half-bridge topology comprises a positive phase and a negative phase, the positive phase comprises an upper tube power switch tube and a lower tube diode, the negative phase comprises a lower tube power switch tube and an upper tube diode, and the high-power switched reluctance motor control circuit further comprises an input capacitor C1, a power generation filter capacitor C2 and a diode D3; wherein the content of the first and second substances,

the collector of the upper tube power switching tube of each phase of asymmetric half-bridge topology, the positive end of an input capacitor C1 and the cathode of a diode D3 are converged to the positive end of the voltage input of the starter;

the cathode of the upper tube diode, the positive end of the power generation filter capacitor C2 and the anode of the diode D3 of each phase of asymmetric half-bridge topology are converged to the positive end of the power generation voltage output;

an emitter of a lower tube power switch tube, an anode of a lower tube diode, a negative end of an input capacitor C1 and a negative end of a power generation filter capacitor C2 of each phase of asymmetric half-bridge topology are converged and then divided into two wiring terminals which are respectively connected to a power generation voltage output negative end and a starter voltage input negative end.

Preferably, the control circuit has a first mode, the first mode is an excitation mode, and when the control circuit is in the first mode, both the upper tube power switching tube and the lower tube power switching tube of the single three-phase asymmetric half-bridge topology are controlled to output a high level.

Preferably, the control circuit has a second mode, the second mode is a follow current mode, when the control circuit is in the second mode, a first upper tube power switching tube of the single three-phase asymmetric half-bridge topology follows current and is controlled to output a high level, and a second lower tube power switching tube of the single three-phase asymmetric half-bridge topology follows current and is controlled to output a high level.

Preferably, the control circuit has a third mode, where the third mode is a follow current mode, and when the control circuit is in the third mode, the first lower tube power switching tube of the single three-phase asymmetric half-bridge topology follows current and is controlled to output a high level, and the second upper tube power switching tube of the single three-phase asymmetric half-bridge topology follows current and is controlled to output a high level.

Preferably, the control circuit has a fourth mode, the third mode is a negative-voltage demagnetization mode, and when the control circuit is in the fourth mode, the two upper tube power switching tubes and the two lower tube power switching tubes of the single-three-phase asymmetric half-bridge topology are both turned off.

A second aspect of the present application provides a control method for a high power switched reluctance motor control circuit, which employs the high power switched reluctance motor control circuit of claim 1, the method comprising:

step 1, the control circuit of the high-power switched reluctance motor forms three control modes by controlling the opening and closing of the upper tube power switching tube and the lower tube power switching tube of the two single-three-phase asymmetric half-bridge topologies, wherein the first mode is an excitation mode, the second mode is an upper tube follow current mode, the third mode is a lower tube follow current mode, the upper tube power switching tube and the lower tube power switching tube of the two asymmetric half-bridge topologies in the excitation mode both output high levels, the upper tube follow current mode refers to the high level output by the upper tube power switching tube of one asymmetric half-bridge topology, and the lower tube follow current mode refers to the high level output by the upper tube power switching tube of the other asymmetric half-bridge topology;

and step S2, controlling the on-off of each upper tube power switch tube and each lower tube power switch tube of the high-power switched reluctance motor control circuit by adopting a cyclic control mode of alternating control of a first mode, a second mode, the first mode and a third mode.

Preferably, the cyclic control method of the alternating control includes:

step S21, when the position angle theta of the motor rotor is in the A-phase conduction interval, the theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onStarting at time, the falling edge of the PWM modulation waveform S2 is counted from 0;

step S22, when the PWM modulation waveform S2 detects a rising edge, G11, G12, G13 and G13 output a high level, where a first upper tube power switch of the single three-phase asymmetric half-bridge topology has a first control signal G11, a first lower tube power switch of the single three-phase asymmetric half-bridge topology has a second control signal G12, a second upper tube power switch of the single three-phase asymmetric half-bridge topology has a third control signal G13, and a second lower tube power switch of the single three-phase asymmetric half-bridge topology has a fourth control signal G13;

step S23, when the PWM modulation waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal goes low and the G12 signal remains.

The power device number is reduced and the power-to-weight ratio and reliability of the system are improved by optimizing a control strategy for a high-power switched reluctance motor and comparing the control strategy with a traditional double three-phase asymmetric half-bridge power topology under the condition that the stress level of the power device is not increased.

Drawings

Fig. 1 is a schematic diagram of a conventional switched reluctance single three phase asymmetric half bridge power topology.

Fig. 2 is a timing diagram of conventional single three-phase asymmetric half-bridge control signals.

Fig. 3 is a schematic diagram of a conventional dual three-phase asymmetric half-bridge power topology.

Fig. 4 is a timing diagram of conventional dual three-phase asymmetric half-bridge control signals.

Fig. 5 is a schematic diagram of a dual three-phase asymmetric half-bridge power topology of a preferred embodiment of a control circuit for a high power switched reluctance motor according to the present application.

Fig. 6 is a schematic diagram of a positive-voltage excitation mode when a control circuit of a high-power switched reluctance motor based on the present application adopts a conventional strategy for control.

Fig. 7 a-7 d are respectively operation mode diagrams of control strategies according to a preferred embodiment of the control method for the high-power switched reluctance motor control circuit of the present application.

Fig. 8 is a timing diagram of a control strategy of a preferred embodiment of the control method of the high-power switched reluctance motor control circuit of the present application.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application. Embodiments of the present application will be described in detail below with reference to the drawings.

The first aspect of the application provides a high-power switched reluctance motor control circuit, which comprises two identical single-three-phase asymmetric half-bridge topologies, wherein each phase asymmetric half-bridge topology comprises a positive phase and a negative phase, the positive phase comprises an upper tube power switch tube and a lower tube diode, the negative phase comprises a lower tube power switch tube and an upper tube diode, and the high-power switched reluctance motor control circuit further comprises an input capacitor C1, a power generation filter capacitor C2 and a diode D3; wherein the content of the first and second substances,

the collector of the upper tube power switching tube of each phase of asymmetric half-bridge topology, the positive end of an input capacitor C1 and the cathode of a diode D3 are converged to the positive end of the voltage input of the starter;

the cathode of the upper tube diode, the positive end of the power generation filter capacitor C2 and the anode of the diode D3 of each phase of asymmetric half-bridge topology are converged to the positive end of the power generation voltage output;

an emitter of a lower tube power switch tube, an anode of a lower tube diode, a negative end of an input capacitor C1 and a negative end of a power generation filter capacitor C2 of each phase of asymmetric half-bridge topology are converged and then divided into two wiring terminals which are respectively connected to a power generation voltage output negative end and a starter voltage input negative end.

As shown in fig. 5, the power topology of the present application mainly consists of a dual three-phase asymmetric half-bridge topology, a starting input filter capacitor, and a generating output filter capacitor. The starting input filter capacitor is C1, and the generating output filter capacitor is C2.

In the double three-phase asymmetric half-bridge power topology, the double three-phase asymmetric half-bridge topology is composed of single three-phase asymmetric half-bridge topologies, namely a channel 1 and a channel 2, which have the same structure. The asymmetric half-bridge topologies a1, B1 and C1 of channel 1 are consistent with the asymmetric half-bridge topologies a2, B2 and C2 of channel 2, and the asymmetric half-bridge topology a1 is taken as an example for illustration. The A1 phase asymmetric half-bridge topology is mainly composed of 2 groups of asymmetric half-bridge topologies, wherein the A1 phase + asymmetric half-bridge topology is named as a tube power switch tube VT11, a tube diode D11, an A1 phase-half-bridge module is named as a tube power switch tube VT12, and a tube diode D12.

The collector terminal of the A1 phase + power switch tube VT11, the collector terminal of the B1 phase + power switch tube VT21, the collector terminal of the C1 phase + power switch tube VT31, the positive terminal of the input capacitor C1, the collector terminal of the A2 phase + power switch tube VT13, the collector terminal of the B2 phase + power switch tube VT23, the collector terminal of the C2 phase + power switch tube VT33 and the diode cathode of the D3 are connected through a bus bar to form an electrical reference point which is named as starting input +;

the cathode of the diode D12 of phase A1, the cathode of the diode D22 of phase B1, the cathode of the diode D32 of phase C1, the positive terminal of the generating capacitor C2, the cathode of the diode D14 of phase A2, the cathode of the diode D24 of phase B2, the cathode of the diode D34 of phase C2 and the anode of the diode D3 are connected through bus bars to form an electrical reference point which is named as generating output +.

An anode of a1 phase + diode D11, an emitter terminal of a1 phase-power switching tube VT12, an anode of B1 phase + diode D21, an emitter terminal of B1 phase-power switching tube VT22, an anode of C1 phase + diode D31, an emitter terminal of C1 phase-power switching tube VT32, an anode of a2 phase + diode D13, an emitter terminal of a2 phase-power switching tube VT14, an anode of B2 phase + diode D23, an emitter terminal of B2 phase-power switching tube VT24, an anode of C2 phase + diode D33, an emitter terminal of C2 phase-power switching tube VT34, and a negative terminal of a generation filter capacitor C2 are connected by a bus bar to form an electrical reference point, and 2 connection terminals are named start input-and generation output-.

The A1 phase motor + winding of channel 1 is connected to the common point of the emitter of the power topology A1 phase + power switch tube VT11 and the cathode of the diode D11, the A1 phase motor-winding of channel 1 is connected to the common point of the collector of the power topology A1 phase-power switch tube VT12 and the anode of the diode D12, and other motor phase windings are similar to the power topology and are not described in detail.

Due to the unidirectional conductivity of the diodes D12, D22, D32, D14, D24 and D34, the two single-three-phase asymmetric half-bridge power topologies have no coupling phenomenon and can be independently controlled. Meanwhile, the phase difference between the corresponding phases of the two single three-phase asymmetric half bridges can be adjusted, and the phase difference between the corresponding phases of the two single three-phase asymmetric half bridges is 0 for analysis.

Because the coupling phenomenon does not exist between the two single three-phase asymmetric half-bridge power topologies, the traditional double three-phase asymmetric half-bridge control strategy can be adopted. The power switching tube of each phase is divided into four working modes according to the difference of the on-off state of the power switching tube of each phase, the working mode is illustrated by taking the phase a as an example, and is shown in fig. 6.

In this mode, the switching tubes VT11 and VT13 are turned on, and VT12 and VT14 are turned off. The phase current on the a1 winding freewheels through VT11, D12, D3, and the phase current on the a2 winding freewheels through VT13, D14, D3. As shown in the upper diagram, the current flowing through the diode D3 is 2I. Due to the symmetry of the motor, the same phenomenon exists when the B1 and B2 phase windings, and the C1 and C2 phase windings are operating.

In order to reduce the current flowing through the diode D3, the traditional control strategy is optimized, and a control method of the high-power switch reluctance motor control circuit based on the high-power switch reluctance motor control circuit is provided, so that the current flowing through the diode D3 is reduced to I, the current is reduced by one time, the requirement on the current capacity of D3 is reduced, and the volume and weight of a power device are further reduced. The method mainly comprises the following steps:

step 1, the control circuit of the high-power switched reluctance motor forms three control modes by controlling the opening and closing of the upper tube power switching tube and the lower tube power switching tube of the two single-three-phase asymmetric half-bridge topologies, wherein the first mode is an excitation mode, the second mode is an upper tube follow current mode, the third mode is a lower tube follow current mode, the upper tube power switching tube and the lower tube power switching tube of the two asymmetric half-bridge topologies in the excitation mode both output high levels, the upper tube follow current mode refers to the high level output by the upper tube power switching tube of one asymmetric half-bridge topology, and the lower tube follow current mode refers to the high level output by the upper tube power switching tube of the other asymmetric half-bridge topology;

and step S2, controlling the on-off of each upper tube power switch tube and each lower tube power switch tube of the high-power switched reluctance motor control circuit by adopting a cyclic control mode of alternating control of a first mode, a second mode, the first mode and a third mode.

In some optional embodiments, the cyclic control manner of the alternating control includes:

step S21, when the position angle theta of the motor rotor is in the A-phase conduction interval, the theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onStarting at time, the falling edge of the PWM modulation waveform S2 is counted from 0;

step S22, when the PWM modulation waveform S2 detects a rising edge, G11, G12, G13 and G13 output a high level, where a first upper tube power switch of the single three-phase asymmetric half-bridge topology has a first control signal G11, a first lower tube power switch of the single three-phase asymmetric half-bridge topology has a second control signal G12, a second upper tube power switch of the single three-phase asymmetric half-bridge topology has a third control signal G13, and a second lower tube power switch of the single three-phase asymmetric half-bridge topology has a fourth control signal G13;

step S23, when the PWM modulation waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal goes low and the G12 signal remains.

The novel dual three-phase asymmetric half-bridge topology control strategy of the invention is explained below, and phase a is taken as an example.

When the position angle theta of the motor rotor is in the A-phase conduction interval, the theta is satisfied_on＜θ＜θ_offWhen the power switching tubes VT11, VT12, VT13 and VT14 are controlled to be switched on or off, so that the A phase works in a first mode, a second mode or a third mode; and outside the conduction interval of the a1 and a2 phases, the power switching tubes VT11, VT12, VT13 and VT14 are kept in the off state, so that the a phase works in the fourth mode, and the working mode is as shown in fig. 7. Fig. 7a shows a first mode, which is a positive-pressure excitation mode, wherein VT11 and VT14 normally control the opening and closing together, and VT12 and VT13 normally control the opening and closing together, so for simplicity of description, VT11 and VT14 are controlled by G11, VT12 and VT13 are controlled by G12, and in fig. 7a, both G11 and G12 control the opening state. Fig. 7b is the second mode, which is a zero pressure tube freewheeling mode, G11 open and G12 closed. Fig. 7c is the third mode, zero-throttle tube-freewheel mode, G11 closed, G12 open. Fig. 7d is a fourth mode, which is a negative-pressure demagnetization mode.

At theta_on＜θ＜θ_offIn the meantime, the power topology is operated in an excitation mode or a freewheeling mode by judging the phase currents A1 and A2. In the follow current mode, when the A1 phase adopts upper tube follow current, the A2 phase adopts lower tube follow current; when the a1 phase uses lower tube freewheeling, the a2 phase uses upper tube freewheeling. Meanwhile, the a1 phase adopts a control strategy of alternating one-time upper tube follow current and one-time lower tube follow current, namely, a cycle of mode one → mode two → mode one → mode three is one.

The control signals G11, G12, G13 and G14 of the switch tubes VT11, VT12, VT13 and VT14 are analyzed to simultaneously satisfy the following logical relationship and the formula 2:

when the position angle theta of the motor rotor is in the A-phase conduction interval, theta is satisfied_on≤θ≤θ_offWhen theta is equal to theta_onFrom time to time, the falling edge of the PWM modulation waveform S2 is counted from 0.

When the PWM modulation waveform S2 detects a rising edge, G11, G12 output a high level;

when the PWM waveform S2 detects a falling edge, if i is an odd number, the G11 signal is kept, and the G12 signal outputs a low level; if i is even, the G11 signal goes low and the G12 signal remains.

Control signals G21, G22, G23 and G24 of switching tubes VT21, VT22, VT23 and VT24 also meet the third logical relation and the formula 2 when the position angle theta of the motor rotor is in a B-phase conduction interval; control signals G31, G32, G33 and G34 of the switching tubes VT31, VT32, VT33 and VT34 also satisfy the third logical relation and the formula 2 when the position angle theta of the motor rotor is in the C-phase conduction interval.

The timing diagram of the control signals is shown in fig. 8, in which S1 is a waveform of the position angle θ of the a-phase winding and the relative position of the conduction interval, S2 is a PWM modulation waveform, G11 is a control signal of the switching transistor VT11, G12 is a control signal of the switching transistor VT12, G13 is a control signal of the switching transistor VT13, and G14 is a control signal of the switching transistor VT 14.

On the basis of the traditional double three-phase asymmetric half-bridge power topology, the number of power topology devices is reduced and the volume weight of the power devices is reduced through the optimization of a control strategy, so that the power-weight ratio of the system is improved and the overall reliability of the system is improved.

The above description is only for the specific embodiments of the present application, but the scope of the present application 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 application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.