Buck-boost type high-power-density driving topology for alternating current motor and control method of buck-boost type high-power-density driving topology

Abstract

The invention discloses a buck-boost high-power-density driving topology for an alternating current motor and a control method thereof, and belongs to the field of alternating current motor driving control, the adopted power topology structure is composed of a high-frequency power switch, a high-frequency direct current filter inductor, a single-chip bidirectional switch and an alternating current filter capacitor, and the power topology is formed in a two-stage mode. The preceding stage comprises a group of high-frequency power switches, and the real-time control of the current amplitude of the stator can be realized through the real-time adjustment of the high-frequency power switches; and at the rear stage, an inductor and a double-gate single-chip bidirectional switch form a current source type inversion structure, and the current source type inversion structure directly works in a fixed modulation ratio operation state, so that the phase of the stator current is adjusted. And the driving topology is more helpful to realize wide-speed-range speed regulation of the alternating current motor through voltage boosting and voltage reducing, and the method has very high practicability and application value.

Description

Technical Field

[0001] The present invention relates to the field of AC motor drive control, and in particular to a buck-boost high power density drive topology for an AC motor and a control method thereof. Background Art

[0002] In modern industry and transportation, AC motors are widely used in various drive systems due to their high efficiency, high reliability and good control performance. With the development of technology, the performance requirements for motor drive systems are getting higher and higher, especially in the fields of electric vehicles, industrial automation and aerospace, which put forward higher requirements for the speed regulation range and power density of motor drive systems. In this context, high power density drive topology and its control technology have become a hot topic of research. Existing AC motors are usually driven by traditional two-level voltage source inverters, but there are the following problems: (1) large harmonic currents will be generated during the operation of the motor in a wide speed range, and it is difficult to achieve stable operation of the AC motor in a wide speed range; (2) when applied to electric vehicles or aircraft, it is difficult to maintain a constant ideal state of the bus voltage of the electric drive system during the battery power decline; (3) the energy feedback and management of the motor require the electric drive system to have four-quadrant operation capabilities. Therefore, it is necessary to carry out key technology research on two-stage buck-boost high power density drive system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a buck-boost high-power density drive topology for an AC motor and a control method thereof, aiming to solve the problems of high order of traditional current source inverter control systems, difficult current regulator design and large driver size, so that the motor can maintain stable operation in a wide speed range and maintain a constant ideal state, and have four-quadrant operation capabilities.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a buck-boost high power density drive topology for an AC motor, a hybrid two-stage current source inverter is set to drive the AC motor, the hybrid two-stage current source inverter includes high-frequency power switches S1 to S2, high-frequency DC filter inductors, monolithic bidirectional switches T1 to T6, inverters and AC filter capacitors C1 to C3; wherein one end of the high-frequency power switch S1 is connected to the positive electrode of the external DC voltage source, and the other end is respectively connected to one end of the high-frequency power switch S2, the high-frequency DC filter inductor, the high-frequency power switch S1 to S2, the high-frequency power switch S2 ... one end of the inductor is connected; the other end of the high-frequency DC filter inductor is respectively connected to one end of the monolithic bidirectional switch T1, one end of the monolithic bidirectional switch T3, and one end of the monolithic bidirectional switch T5; the other end of the monolithic bidirectional switch T1, the other end of the monolithic bidirectional switch T3, and the other end of the monolithic bidirectional switch T5 are respectively connected to one end of the monolithic bidirectional switch T2, one end of the monolithic bidirectional switch T4, and one end of the monolithic bidirectional switch T6; the other end of the monolithic bidirectional switch T2, the other end of the monolithic bidirectional switch T4, and the other end of the monolithic bidirectional switch T6 are all connected to the negative electrode of the power supply;

[0005] One end of the monolithic bidirectional switch T2 is respectively connected to the other end of the monolithic bidirectional switch T1 and one end of the AC filter capacitor C1; one end of the monolithic bidirectional switch T4 is respectively connected to the other end of the monolithic bidirectional switch T3 and one end of the AC filter capacitor C2; one end of the monolithic bidirectional switch T6 is respectively connected to the other end of the monolithic bidirectional switch T5 and one end of the AC filter capacitor C3; the other end of the AC filter capacitor C2 is respectively connected to the other end of the AC filter capacitor C1 and the other end of the AC filter capacitor C3.

[0006] A further improvement of the technical solution of the present invention is that the type of high-frequency power switches S1 to S2 is GaN-type wide bandgap devices, and the type of monolithic bidirectional switches T1 to T6 is dual-gate monolithic bidirectional GaN-type transistors.

[0007] A further improvement of the technical solution of the present invention is that: a position sensor is provided in the AC motor, and the output current i of the inverter wa A current sensor is provided on the side.

[0008] A control method for a buck-boost high power density drive topology for an AC motor adopts a front-end and back-end coordinated control strategy. First, a wide bandgap device is introduced in the front-end, i.e., the DC side, to control the inductor current at high frequency, and at the same time, the stator current amplitude is quickly adjusted. Secondly, the back-end, i.e., the AC side, only needs to provide a current phase correction control loop, and the back-end closed-loop system is reduced in order. The specific steps are as follows:

[0009] Step 1: Get the position signal of the AC motor, perform differential processing on the position signal to get the real-time speed of the motor, and then convert the real-time speed of the motor ω r With the predetermined speed reference value ωr * After the difference is made, the output of the PI regulator is used to obtain the given value of the previous inductor current i dc * ;

[0010] Step 2: In the previous stage, the high-frequency DC inductor current i dc and the predetermined torque current reference value i dc * After the difference is made, the driving signals g and g of the high-frequency power switch S1 and the high-frequency power switch S2 are obtained through the bang-bang regulator, and the operation of the high-frequency power switch S1 and the high-frequency power switch S2 are controlled according to the driving signals;

[0011] Step 3: Obtain the feedback value of the difference regulator;

[0012] Step 4: Obtain the switch tube driving signal through the SVM strategy;

[0013] Step 5: In the latter stage, according to the preset modulation ratio m=1, phase correction angle and AC motor position signal θ r , combined with the fixed modulation ratio current space vector modulation SVM strategy, the switching signals of the monolithic bidirectional switches T1 to T6 are obtained to control the operation of the monolithic bidirectional switches T1 to T6.

[0014] The further improvement of the technical solution of the present invention is that the specific steps of step 3 are as follows:

[0015] Step 3.1: Use the zero-crossing detection method to convert the two sinusoidal wave signals output by the position sensor and the current sensor into square wave signals with the same width as their positive half-cycles. After performing an XOR operation on the square wave signal, the absolute value of the phase difference between the two sinusoidal wave signals can be expressed;

[0016] Step 3.2: The actual phase relationship between the two signals is determined by designing a lead-lag judgment unit. The lead-lag judgment unit calculates the lead-lag relationship and the absolute value of the phase difference to obtain the phase difference between the two input sinusoidal wave signals. A positive value represents that the current signal lags behind the Hall voltage signal, and a negative value represents that the current signal leads the Hall voltage signal.

[0017] Step 3.3: After passing through a low-pass filter, a continuously changing phase difference Δθ is obtained as the feedback value of the phase difference regulator.

[0018] A further improvement of the technical solution of the present invention is that the zero-crossing detection method is specifically to rectify and filter the input signal, and then compare it with a reference level. When the input signal passes through the zero point, the output signal will jump, and this jump is the zero-crossing point. When the sine wave transitions from the positive half-cycle to the negative half-cycle, the output signal changes from a high level to a low level, and when the sine wave transitions from the negative half-cycle to the positive half-cycle, the output signal changes from a low level to a high level, thereby generating a square wave signal. The square wave signal is characterized in that the duration of its high level and low level are equal, which corresponds to the positive half-cycle and negative half-cycle of the sine wave.

[0019] The further improvement of the technical solution of the present invention is that the specific steps of step 4 are as follows:

[0020] Step 4.1: Use the phase difference acquisition unit to obtain the linear Hall 1 output signal V1 and the A phase current signal i sa The phase difference Δθ between them;

[0021] Step 4.2: Use the PI regulator to adjust the phase difference between the two to the reference value Δθ * ; PI regulator is a phase difference regulator; Phase difference reference value Δθ * Determined by the linear Hall installation position;

[0022] Step 4.3: The PI regulator then outputs the current phase correction angle, and the switch tube drive signal can be obtained through the fixed modulation ratio current space vector modulation SVM strategy, ultimately achieving the control target of the maximum torque current ratio.

[0023] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is: by adopting the front-end and rear-end coordinated control strategy, compared with the traditional CSI motor drive system control strategy, the wide bandgap device is first introduced through the front-end (DC side) to control the inductor current at high frequency, and the stator current amplitude is quickly adjusted at the same time, which is helpful for the application of the rear-end fixed modulation ratio control strategy; secondly, the rear-end (AC side) only needs to provide a current phase correction control loop, and the control object is no longer a second-order link containing a resonant spike, which realizes the reduced-order control of the rear-end closed-loop system, greatly improving the system stability and control performance. The front-end adopts a DC filter inductor, so that there is no need to achieve a voltage stabilization effect through a large capacitor. The control strategy of the front-end speed regulation and the rear-end phase change can, on the one hand, follow the load to regulate the DC side current, reduce losses and facilitate motor starting; on the other hand, the rear-end fixed modulation ratio control facilitates the application of various modulation strategies. By making the type of the monolithic bidirectional switch T1 to T6 a dual-gate monolithic bidirectional GaN transistor, the reverse current prevention capability and reverse voltage withstand capability of the inverter branch can be improved, and the system cost and switching loss can be reduced. The topology and control of this application can realize the four-quadrant operation of the AC motor and realize the free switching between the motor state and the power generation state. The DC / DC converter in the front stage of the driving topology can realize the step-up and step-down of the motor input side, which is conducive to the smooth speed regulation of the AC motor in a wide speed range and improves the reliability of the motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a general implementation block diagram of the topology and control of the present invention;

[0026] Figure 2 It is a design and implementation block diagram of the front-stage main current source controller of the present invention;

[0027] Figure 3 It is a schematic diagram of the design of the phase difference acquisition scheme of the present invention;

[0028] Figure 4 It is a block diagram of the design and implementation of the back-end single current sensor phase-locked loop of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments:

[0030] like Figure 1As shown, a general implementation block diagram of a buck-boost high power density drive topology for an AC motor and its control method, the upper part is a hybrid two-stage current source inverter topology and the AC motor driven by it, and the lower part is the operation module and data transmission process required to control the hybrid two-stage current source inverter topology. The specific topological structure is to set a hybrid two-stage current source inverter to drive an AC motor, and the hybrid two-stage current source inverter includes high-frequency power switches S1 to S2, high-frequency DC filter inductors, monolithic bidirectional switches T1 to T6, inverters, and AC filter capacitors C1 to C3; wherein one end of the high-frequency power switch S1 is connected to the positive electrode of an external DC voltage source, and the other end is respectively connected to one end of the high-frequency power switch S2 and one end of the high-frequency DC filter inductor; the other end of the high-frequency DC filter inductor is respectively connected to one end of the monolithic bidirectional switch T1, one end of the monolithic bidirectional switch T3, and one end of the monolithic bidirectional switch T5; the other end of the monolithic bidirectional switch T1, the other end of the monolithic bidirectional switch T3, and the other end of the monolithic bidirectional switch T5 are respectively connected to one end of the monolithic bidirectional switch T2, one end of the monolithic bidirectional switch T4, and one end of the monolithic bidirectional switch T6; the other end of the monolithic bidirectional switch T2, the other end of the monolithic bidirectional switch T4, and the other end of the monolithic bidirectional switch T6 are all connected to the negative electrode of the power supply;

[0031] One end of the monolithic bidirectional switch T2 is respectively connected to the other end of the monolithic bidirectional switch T1 and one end of the AC filter capacitor C1; one end of the monolithic bidirectional switch T4 is respectively connected to the other end of the monolithic bidirectional switch T3 and one end of the AC filter capacitor C2; one end of the monolithic bidirectional switch T6 is respectively connected to the other end of the monolithic bidirectional switch T5 and one end of the AC filter capacitor C3; the other end of the AC filter capacitor C2 is respectively connected to the other end of the AC filter capacitor C1 and the other end of the AC filter capacitor C3. Among them, the type of high-frequency power switches S1 to S2 is GaN type wide bandgap devices, and the type of monolithic bidirectional switches T1 to T6 is dual-gate monolithic bidirectional GaN type transistors. A position sensor is provided in the AC motor, and the output current i of the inverter wa A current sensor is provided on the side to provide data for the subsequent control method. The high-frequency power switches S1 to S2 are GaN wide bandgap devices, and the monolithic bidirectional switches T1 to T6 are dual-gate monolithic bidirectional GaN transistors, which can improve the inverter branch's ability to prevent current reverse and reverse withstand voltage, and can reduce system cost and switching loss.

[0032] The above topology adopts the corresponding control method of the buck-boost high power density drive topology for AC motors for driving, and adopts a new front-end and back-end coordinated control strategy. First, the wide bandgap device is introduced in the front-end, i.e., the DC side, to control the inductor current at high frequency, and at the same time, the stator current amplitude is quickly adjusted. The real-time control of the stator current amplitude can be achieved through real-time adjustment of the high-frequency power switch. Secondly, the back-end is composed of an inductor and a dual-gate monolithic bidirectional switch to form a current source inverter structure, which directly works in a fixed modulation ratio operating state to adjust the phase of the stator current. The back-end, i.e., the AC side, only needs to provide a current phase correction control loop, realizing the reduced-order control of the back-end closed-loop system. The specific steps are as follows:

[0033] Step 1: Get the position signal of the AC motor, perform differential processing on the position signal to get the real-time speed of the motor, and then convert the real-time speed of the motor ω r With the predetermined speed reference value ω r * After the difference is made, the output of the PI regulator is used to obtain the given value of the previous inductor current i dc * ;

[0034] Step 2: If Figure 2 As shown, in the previous stage, the high-frequency DC inductor current i dc and the predetermined torque current reference value i dc * After the difference is made, the drive signals g and g of the high-frequency power switch S1 and the high-frequency power switch S2 are obtained through the bang-bang regulator, and the operation of the high-frequency power switch S1 and the high-frequency power switch S2 is controlled according to the drive signals; while introducing the bang-bang regulator, thanks to the high-frequency power switch S1 to S2 introduced in the previous stage for high-frequency chopping, the disadvantage of the large steady-state jitter of the bang-bang regulator is overcome, while retaining its advantage of fast dynamic response, and achieving smooth and fast regulation of the main current source under low inductance. Since the "bang-bang" regulator is implemented with a digital controller and has a fixed actual inductor current sampling frequency, setting the loop width to zero will not cause the switch tube to switch repeatedly.

[0035] Step 3: Obtain the feedback value of the difference regulator;

[0036] Step 3.1: Use the zero-crossing detection method to convert the two sinusoidal wave signals output by the position sensor and the current sensor into square wave signals with the same width as their positive half-cycles. After performing an XOR operation on the square wave signal, the absolute value of the phase difference between the two sinusoidal wave signals can be represented; the zero-crossing detection method is specifically to rectify and filter the input signal, and then compare it with a reference level. When the input signal passes through the zero point, the output signal will jump. This jump is the zero crossing point. When the sine wave transitions from the positive half-cycle to the negative half-cycle, the output signal changes from a high level to a low level. When the sine wave transitions from the negative half-cycle to the positive half-cycle, the output signal changes from a low level to a high level, thereby generating a square wave signal. The characteristic of the square wave signal is that the duration of its high level and low level is equal, which corresponds to the positive half-cycle and negative half-cycle of the sine wave.

[0037] Step 3.2: Determine the actual phase relationship between the two signals by designing a lead-lag judgment unit, such as Figure 3 As shown, the lead-lag judgment unit consists of several parts: Signal sampling and processing: sampling and digital processing of the input sinusoidal wave signal. Phase detection circuit: determine the phase angle of the two signals to compare their phase relationship. Logic judgment circuit: based on the phase detection result, use comparators and logic gates to determine whether the signal is leading or lagging. Lead-lag network: may include filters that adjust the phase of the signal to achieve a lead or lag effect. Gain and time constant: parameters for adjusting the lead or lag effect. Output logic: outputs a digital signal indicating whether the signal is leading or lagging for use by the control system. The lead-lag judgment unit calculates the lead-lag relationship and the absolute value of the phase difference to obtain the phase difference between the two input sinusoidal wave signals, that is, a positive value represents that the current signal lags behind the Hall voltage signal, and a negative value represents that the current signal leads the Hall voltage signal;

[0038] Step 3.3: After passing through a low-pass filter, a continuously changing phase difference Δθ is obtained as the feedback value of the phase difference regulator.

[0039] Step 4: Figure 4 As shown, the switch tube driving signal is obtained by the SVM strategy;

[0040] Step 4.1: Use the phase difference acquisition unit to obtain the linear Hall 1 output signal V1 and the A phase current signal i sa The phase difference Δθ between them;

[0041] Step 4.2: Use the PI regulator to adjust the phase difference between the two to the reference value Δθ * ; PI regulator is a phase difference regulator; Phase difference reference value Δθ * Determined by the linear Hall installation position;

[0042] Step 4.3: The PI regulator then outputs the current phase correction angle, and the switch tube drive signal can be obtained through the fixed modulation ratio current space vector modulation SVM strategy, ultimately achieving the control target of the maximum torque current ratio.

[0043] Step 5: In the latter stage, according to the preset modulation ratio m=1, phase correction angle and AC motor position signal θ r , combined with the fixed modulation ratio current space vector modulation SVM strategy, the switching signals of the monolithic bidirectional switches T1 to T6 are obtained to control the operation of the monolithic bidirectional switches T1 to T6. From the perspective of improved design of the main power topology and control strategy, this application takes reduced-order control as the main goal, and proposes a front- and rear-stage coordinated control strategy based on a hybrid two-stage current source inverter. The front stage uses wide bandgap devices to control the stator current amplitude; the back stage is designed with a single current sensor phase-locked loop, which realizes automatic current phase correction by locking the rotor position signal with the phase current, thereby ensuring the realization of reduced-order control while further improving system stability and reducing the size of the driver.

[0044] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A buck-boost high power density drive topology for an AC motor, characterized in that: A hybrid two-stage current source inverter is provided to drive an AC motor, the hybrid two-stage current source inverter comprising high-frequency power switches S1 to S2, high-frequency DC filter inductors, monolithic bidirectional switches T1 to T6, an inverter and AC filter capacitors C1 to C3; wherein one end of the high-frequency power switch S1 is connected to the positive electrode of an external DC voltage source, and the other end is respectively connected to one end of the high-frequency power switch S2 and one end of the high-frequency DC filter inductor; the other end of the high-frequency DC filter inductor is respectively connected to one end of the monolithic bidirectional switch T1, one end of the monolithic bidirectional switch T3 and one end of the monolithic bidirectional switch T5; the other end of the monolithic bidirectional switch T1, the other end of the monolithic bidirectional switch T3 and the other end of the monolithic bidirectional switch T5 are respectively connected to one end of the monolithic bidirectional switch T2, one end of the monolithic bidirectional switch T4 and one end of the monolithic bidirectional switch T6; the other end of the monolithic bidirectional switch T2, the other end of the monolithic bidirectional switch T4 and the other end of the monolithic bidirectional switch T6 are all connected to the negative electrode of the power supply; One end of the monolithic bidirectional switch T2 is respectively connected to the other end of the monolithic bidirectional switch T1 and one end of the AC filter capacitor C1; one end of the monolithic bidirectional switch T4 is respectively connected to the other end of the monolithic bidirectional switch T3 and one end of the AC filter capacitor C2; one end of the monolithic bidirectional switch T6 is respectively connected to the other end of the monolithic bidirectional switch T5 and one end of the AC filter capacitor C3; the other end of the AC filter capacitor C2 is respectively connected to the other end of the AC filter capacitor C1 and the other end of the AC filter capacitor C3.

2. According to claim 1, a buck-boost high power density drive topology for an AC motor is characterized in that: The type of high frequency power switches S1 to S2 is GaN type wide bandgap devices, and the type of monolithic bidirectional switches T1 to T6 is double-gate monolithic bidirectional GaN type transistors.

3. The buck-boost high power density drive topology for an AC motor according to claim 1, characterized in that: The AC motor is equipped with a position sensor, and the output current i of the inverter wa A current sensor is provided on the side.

4. A control method for a buck-boost high power density drive topology for an AC motor, used for driving and controlling the topology as claimed in any one of claims 1 to 3, characterized in that: The front-end and rear-end coordinated control strategy is adopted. First, a wide bandgap device is introduced in the front-end, i.e., the DC side, to control the inductor current at high frequency, and at the same time, the stator current amplitude is quickly adjusted. Secondly, the rear-end, i.e., the AC side, only needs to provide a current phase correction control loop, realizing the reduced-order control of the rear-end closed-loop system. The specific steps are as follows: Step 1: Get the position signal of the AC motor, perform differential processing on the position signal to get the real-time speed of the motor, and then convert the real-time speed of the motor ω r With the predetermined speed reference value ω r * After the difference is made, the output of the PI regulator is used to obtain the given value of the previous inductor current i dc * ; Step 2: In the previous stage, the high-frequency DC inductor current i dc and the predetermined torque current reference value i dc * After the difference is made, the driving signals g and g of the high-frequency power switch S1 and the high-frequency power switch S2 are obtained through the bang-bang regulator. Controlling the operation of the high-frequency power switch S1 and the high-frequency power switch S2 according to the driving signal; Step 3: Obtain the feedback value of the difference regulator; Step 4: Obtain the switch tube driving signal through the SVM strategy; Step 5: In the latter stage, according to the preset modulation ratio m=1, phase correction angle and AC motor position signal θ r , combined with the fixed modulation ratio current space vector modulation SVM strategy, the switching signals of the monolithic bidirectional switches T1 to T6 are obtained to control the operation of the monolithic bidirectional switches T1 to T6.

5. The control method of the buck-boost high power density drive topology for an AC motor according to claim 4, characterized in that: Step 3 The specific steps are as follows: Step 3.1: Use the zero-crossing detection method to convert the two sinusoidal wave signals output by the position sensor and the current sensor into square wave signals with the same width as their positive half-cycles. After performing an XOR operation on the square wave signal, the absolute value of the phase difference between the two sinusoidal wave signals can be expressed; Step 3.2: The actual phase relationship between the two signals is determined by designing a lead-lag judgment unit. The lead-lag judgment unit calculates the lead-lag relationship and the absolute value of the phase difference to obtain the phase difference between the two input sinusoidal wave signals. A positive value represents that the current signal lags behind the Hall voltage signal, and a negative value represents that the current signal leads the Hall voltage signal. Step 3.3: After passing through a low-pass filter, a continuously changing phase difference Δθ is obtained as the feedback value of the phase difference regulator.

6. The control method of the buck-boost high power density drive topology for an AC motor according to claim 5, characterized in that: The zero-crossing detection method is specifically to rectify and filter the input signal, and then compare it with a reference level. When the input signal passes through the zero point, the output signal will jump. This jump is the zero crossing point. When the sine wave transitions from the positive half-cycle to the negative half-cycle, the output signal changes from a high level to a low level. When the sine wave transitions from the negative half-cycle to the positive half-cycle, the output signal changes from a low level to a high level, thereby generating a square wave signal. The characteristic of the square wave signal is that the duration of its high level and low level is equal, which corresponds to the positive half-cycle and negative half-cycle of the sine wave.

7. The control method of the buck-boost high power density drive topology for an AC motor according to claim 5, characterized in that: Step 4 The specific steps are as follows: Step 4.1: Use the phase difference acquisition unit to obtain the linear Hall 1 output signal V1 and the A phase current signal i sa The phase difference Δθ between them; Step 4.2: Use the PI regulator to adjust the phase difference between the two to the reference value Δθ * ; PI regulator is a phase difference regulator; Phase difference reference value Δθ * Determined by the linear Hall installation position; Step 4.3: The PI regulator then outputs the current phase correction angle, and the switch tube drive signal can be obtained through the fixed modulation ratio current space vector modulation SVM strategy, ultimately achieving the control target of the maximum torque current ratio.

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