CN110460276A - A rare-earth permanent magnet motor drive system that suppresses zero-sequence current - Google Patents

Abstract

The present invention relates to magneto control fields, disclose a kind of few rare-earth permanent-magnet electric machine control system for inhibiting zero-sequence current, including the open few rare earth permanent magnet brushless motor of two-level inverter I, two-level inverter II, winding, power supply, electric machine controller, position sensor, current sensor and voltage sensor；Wherein, the electric machine controller includes position and speed calculation module, abc/dq0 module, 0 module of dq0/ α β, non-common mode voltage SVPWM module, rotational speed regulation module, d shaft current adjustment module, q shaft current adjustment module, mixture control module.Compared with prior art, the present invention can alleviate the disadvantage that few rare-earth permanent-magnet electric machine resists irreversible degaussing ability weak, reduce dependence of the motor to rare earth material, and effectively inhibit zero-sequence current, to obtain sinusoidal three-phase symmetrical phase current, motor is enabled to obtain ideal current waveform.

Description

A rare-earth permanent magnet motor drive system that suppresses zero-sequence current

technical field

The invention relates to the field of permanent magnet motor control, in particular to a rare-earth permanent magnet motor control system for suppressing zero-sequence current.

Background technique

Permanent magnet motors have the advantages of small size, high efficiency, easy maintenance and strong adaptability to the environment, and are widely used in many high-performance drive fields. Vehicle drive motor is one of the key executive components of hybrid electric vehicles and electric vehicles, and its driving performance directly affects the vehicle performance of hybrid electric vehicles and electric vehicles. Traditional vehicle drive motors mainly use built-in rare earth permanent magnet brushless motors, which have the advantages of high efficiency and high power density.

In recent years, with the increase in the price of rare earth materials and the increasing scarcity of rare earth resources, permanent magnet brushless motors with rare earth and non-rare earth materials such as AlNiCo and ferrite have been developed to alleviate the dependence on rare earth materials. Fields such as power vehicles that require a large number of permanent magnet brushless motors are of strategic importance. However, due to the low coercive force of the ferrite material added to rare earth motors, the ability to resist irreversible demagnetization is weak, and the risk of using field weakening control to increase the speed range is greater. Therefore, seeking a control strategy that can eliminate or alleviate the risk of irreversible demagnetization of rare-earth permanent magnet brushless motors and at the same time broaden the motor speed range has become an urgent problem to be solved in the development of rare-earth and non-rare-earth motors for electric vehicles.

As Takahashi I first proposed the open-winding asynchronous motor structure, the open-winding topology has received attention and application in the fields of induction motors and permanent magnet brushless motors. The winding open structure is to open the neutral point of the motor, and connect an inverter at each end. Compared with the traditional neutral point connection topology, under the same DC supply voltage condition, the winding open topology can obtain a larger voltage vector, so it can effectively widen the operating range of the motor speed, and has high voltage utilization rate, device It has the advantages of low withstand voltage, good output voltage waveform, and small output harmonics. Therefore, for rare-earth permanent magnet brushless motors that use ferrite and NdFeB combined excitation, the use of open winding topology can delay the rare-earth permanent magnet motor from entering the weak magnetic field, effectively alleviating the shortcomings of the rare-earth motor's weak resistance to irreversible demagnetization , which is of great research significance.

Winding open topology Since an inverter is connected to each end of the winding, a scheme for independently supplying power to the two inverters can be adopted. However, independent power supply requires more hardware cost and larger volume, which does not meet the requirements of compact layout, low cost and high performance of electric vehicles. Therefore, the present invention uses a structure in which a single DC power supply supplies power to two inverters at the same time. Due to the combined excitation of NdFeB and ferrite, the permanent magnet brushless motor with rare earth combination excitation greatly increases the difficulty of magnetic circuit design. At the same time, limited by the processing technology, the phase potential generated by the motor rotation will inevitably produce 3, 9 subharmonic. When the open topology of the windings powered by a single DC source is used, the 3rd and 9th harmonics will not be eliminated inside the motor system and will remain in the motor drive system. The zero-sequence current generated will cause the motor to vibrate and even damage the motor.

Therefore, how to effectively suppress the zero-sequence current so as to obtain a sinusoidal three-phase symmetrical phase current has become an urgent problem to be solved in the development of an open-winding rare-earth rare-earth permanent magnet brushless motor.

Contents of the invention

Purpose of the invention: Aiming at the problems existing in the prior art, the present invention provides an open-winding motor drive system capable of widening the operating range of the rare-earth permanent magnet brushless motor, so as to alleviate the ability of the rare-earth permanent magnet motor to resist irreversible demagnetization Weak disadvantages, reducing the motor's dependence on rare earth materials. Aiming at the problem of zero-sequence current in the open-winding rare-earth permanent magnet brushless motor powered by a single DC power supply, a permanent magnet motor drive system that suppresses the zero-sequence current is proposed, so that the motor can obtain an ideal current waveform.

Technical solution: The present invention provides a rare-earth permanent magnet motor control system that suppresses zero-sequence current, including a two-level inverter I, a two-level inverter II, an open-winding rare-earth permanent magnet brushless motor, Power supply, motor controller, position sensor, current sensor and voltage sensor, the motor controller is connected to the winding open-type few rare earth permanent magnet brushless motor through the position sensor and the current sensor respectively, and the voltage output terminal of the power supply is connected by the voltage The sensor is connected to the motor controller, the signal output terminal of the motor controller is connected to the input terminals of the two-level inverter I and the two-level inverter II, and the two-level inverter I , The output ends of the two-level inverter II are connected to the open-winding less rare earth permanent magnet brushless motor;

Wherein, the motor controller includes a position and speed calculation module, an abc/dq0 module, a dq0/αβ0 module, a common-mode voltage-free SVPWM module, a speed regulation module, a d-axis current regulation module, a q-axis current regulation module and a hybrid controller module, the hybrid controller module includes a proportional link and a second-order generalized integrator, the second-order generalized integrator is used to adjust the zero-sequence harmonic component, and the proportional link is used to improve the dynamic response of the zero-sequence current suppression method.

Further, the power supply is a DC power supply, electrically connected to the two-level inverter I and the two-level inverter II respectively, and simultaneously the two-level inverter I and the two-level inverter Device II power supply.

Further, the two-level inverter I and the two-level inverter II both have a three-leg structure, and each bridge arm is composed of two IGBT switching devices and reverse diodes connected in parallel with them respectively, and the windings are open The six connection terminals of the rare-earth permanent magnet brushless motor are respectively connected to the output terminals of the six bridge arms of the two-level inverter I and the two-level inverter II.

Further, the motor controller uses the position signal output by the position sensor, the three-phase phase current detected by the current sensor, and the bus voltage detected by the voltage sensor as input terminals, and synthesizes 12 PWM signals through the motor controller, which are respectively connected with two Signal connection of 12 IGBT switching devices of the level inverter I and the two-level inverter II.

Further, the output terminal of the current sensor is connected to the input terminal of the abc/dq0 module, and the output terminal of the abc/dq0 module is respectively connected to the input terminals of the d-axis current regulation module, the q-axis current regulation module, and the hybrid controller module; The output terminal of the voltage sensor is respectively connected to the input terminal of the d-axis current regulation module and the q-axis current regulation module; the speed regulation module is connected to the input terminal of the q-axis current regulation module; the output terminal of the position sensor is connected to the position connected to the input end of the speed calculation module, the output end of the position and speed calculation module is respectively connected to the input end of the speed adjustment module, the hybrid controller module, and the dq0/αβ0 module; the output end of the dq0/αβ0 module is connected to the non-common-mode voltage SVPWM The input terminals of the modules are connected, and the signal output terminals of the SVPWM module without common mode voltage are respectively connected with the input terminals of the two-level inverter I and the two-level inverter II.

Beneficial effect:

1. The present invention adopts an open winding circuit topology, which can obtain three-level modulation effects under the same DC power supply conditions. The multi-level effect can improve voltage utilization and reduce output voltage harmonics, and is different from traditional midpoint Compared with the clamped three-level inverter, there is no mid-point voltage fluctuation problem in the latter; on this basis, the open structure of the winding can also broaden the operating range of the motor speed, which is especially suitable for rare-earth inverters used in the field of electric vehicles. The permanent magnet brushless motor can delay the rare earth permanent magnet motor from entering the weak field, reduce the risk of irreversible demagnetization of the rare earth permanent magnet motor, and realize the purpose of wide speed regulation operation.

2. The winding open hardware topology adopted in the present invention needs to coordinate and control two standard two-level inverters to work simultaneously. Using the SVPWM modulation strategy that does not generate zero-sequence voltage, the voltage vectors generated by the two inverters will not generate common-mode voltage at any time, which reduces the impact of the modulation method on the motor; coordinate the two inverters at the same time The switching sequence minimizes the switching loss of the switching device, thereby prolonging the service life of the motor system.

3. The present invention aims at the 3rd harmonic of the opposite electromotive force of the motor due to the difficulty of motor design and processing errors caused by open-winding less rare-earth permanent magnet brushless motors, and proposes a zero-sequence harmonic current suppression algorithm on the basis of vector control strategies , by replacing the integral link in the proportional-integral regulator with a second-order generalized integrator, a hybrid controller is formed, which can form a zero-sequence current closed-loop loop, and the controller generates zero-sequence compensation voltage u ₀ ^* compensated back EMF 3 in the zero-sequence loop sub-harmonic, to achieve the purpose of real-time closed-loop adjustment of the zero-sequence current. On the basis that the SVPWM modulation strategy does not generate a common-mode voltage, the influence of the zero-sequence harmonic of the back EMF on the phase current of the motor is eliminated. This suppression strategy regulator has a simple structure, reduces the difficulty of algorithm implementation, does not need to increase hardware to suppress zero-sequence current harmonics, and saves hardware costs.

4. The present invention adopts the winding open circuit topology powered by a single DC power supply, which can save two power supply buses and the voltage stabilizing electrolytic capacitor of the inverter on one side, reduce the volume and system cost of the motor drive system, and improve the operation of the system reliability.

5. The winding open topology used in the present invention, the addition of two inverters under the SVPWM modulation strategy can obtain more voltage vectors, greatly improving the fault tolerance of the motor, and in the event of inverter failure and motor failure It can still use abundant residual voltage vectors to ensure the stable operation of the motor, and is especially suitable for applications requiring high reliability and high stability such as electric vehicles and hybrid vehicles.

Description of drawings

Fig. 1 structure diagram of the drive system of the single DC power supply winding open type less rare earth permanent magnet brushless motor adopted by the present invention;

Figure 2 is an overall block diagram of the vector control of the single DC power supply winding open type less rare earth permanent magnet brushless motor drive system adopted by the present invention;

Fig. 3 internal control block diagram of the zero-sequence current hybrid controller module proposed by the present invention;

The SVPWM modulation space vector distribution diagram without common mode voltage that Fig. 4 the present invention adopts;

Figure 5 The voltage waveform when there is no back EMF zero-sequence harmonic;

Figure 6 has the voltage waveform when there is back EMF zero-sequence harmonic;

Figure 7 The current waveform when there is no back EMF zero-sequence harmonic;

Figure 8 shows the current waveform when there is a back EMF zero sequence harmonic;

Fig. 9 is the voltage and current waveform after adopting the zero-sequence current suppression strategy proposed by the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings. As shown in FIG. 1 , it is a hardware platform for implementing a zero-sequence harmonic current suppression strategy. The present invention includes a two-level inverter I1, a two-level inverter II2, an open-winding less rare earth permanent magnet brushless motor 3, a power supply 4, a motor controller 5, a position sensor 6, a current sensor 7 and a voltage sensor 8. The model of the position sensor 6 is TS5314N512, the model of the current sensor 7 is CSM100B, and the model of the voltage sensor 8 is VSM025A.

Wherein, the power supply 4 is a DC power supply, which is connected to the two-level inverter I1 and the two-level inverter II2, and supplies power to two standard two-level inverters I1 and two-level inverter II2 at the same time ; The open-winding less rare-earth permanent magnet brushless motor 3 opens the neutral point of the traditional motor, and leads out to 6 connection terminals respectively a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ , a ₁ a ₂ , b ₁ b ₂ , c ₁ c ₂ are the output terminals at both ends of the motor A-phase, B-phase, and C-phase windings respectively; the two-level inverter I1 and the two-level inverter II2 both have a three-leg structure , each bridge arm consists of two IGBT switching devices (V ₁₁ , V ₁₃ , V ₁₅ , V ₁₄ , V ₁₆ , V ₁₂ , V ₂₁ , V ₂₃ , V ₂₅ , V ₂₄ , V ₂₆ , V ₂₂ ) and Composed of reverse diodes (D ₁₁ , D ₁₃ , D ₁₅ , D ₁₄ , D ₁₆ , D ₁₂ , D ₂₁ , D ₂₃ , D ₂₅ , D ₂₄ , D ₂₆ , D ₂₂ ) in parallel with it, and the winding is open and less rare earth The output terminals a ₁ , b ₁ , and c ₁ of the permanent magnet brushless motor 3 are respectively connected to the output ends of the three bridge arms of the two-level inverter I1, and the output terminals a ₂ , b ₂ , and c ₂ are respectively connected to the two-level inverter The output terminals of the three bridge arms of the transformer II2; the position sensor 6 is connected with the motor controller 5 and the winding open type less rare earth permanent magnet brushless motor 3 for detecting the real-time rotor position of the motor; the current sensor 7 is connected with the motor controller 5 is connected with open-winding less rare-earth permanent magnet brushless motor 3 for detecting three-phase phase currents i _a , i _b , i _c ; voltage sensor 8 is connected with motor controller 5 and the voltage output end of power supply 4 for To collect the bus voltage U _dc .

The motor controller 5 takes the position signal output by the position sensor 6, the three-phase phase currents i _a ~ i _c detected by the current sensor 7, and the bus voltage U _dc detected by the voltage sensor 8 as inputs, and synthesizes 12 channels of PWM through the motor controller 5 Signals, 12 channels of PWM signals are connected to 12 IGBT switching devices of the two inverters, and are used to drive and control the two-level inverter I1 and the two-level inverter II2 respectively. The internal block diagram is shown in Figure 2 shown. The motor controller 5 includes a position and speed calculation module 9, an abc/dq0 module 10, a dq0/αβ0 module 14, a common-mode voltage-free SVPWM module 15, a speed regulation module 11, a d-axis current regulation module 13, and a q-axis current regulation module 12 and hybrid controller module 16.

As shown in Figure 2, this embodiment is based on the double closed-loop vector control with i _d =0, and suppresses the zero-sequence current on the basis of it, specifically including the following steps:

Step 1: Collect the position signal through the position sensor 6 , collect the real-time value of the three-phase phase current through the current sensor 7 , collect the DC bus voltage U _dc through the voltage sensor 8 , and input the signal to the motor controller 5 .

In step 2, the position signal input to the motor controller 5 passes through the position and speed calculation module 9, and the electrical angle θ of the rotor is outputted, and the real-time rotational speed n of the motor is measured at the same time. The sampled three-phase phase currents i _a , i _b , i _c are transformed by abc/dq0 to output i _d , i _q , i ₀ . The transformation formula is:

Step 3, use the control strategy of id = 0, make a difference between the given id ^* and the id output by the abc/ _dq0 module 10, obtain Δi _d , and input it to the _d -axis current regulation module 13, _d The axis current adjustment module 13 is a PI link, which has both amplitude limiting and per unit functions. The range of u _d ^* output by the d-axis current adjustment module 13 is limited to 0-1. Its expression is:

Wherein, U _dc is the DC bus voltage sampled by the aforementioned voltage sensor 8; k _p is the proportional gain of the d-axis current regulation module 13; k _i is the integral gain of the d-axis current regulation module 13; z is the z transformation operator; sgn() is a sign function; u _dLim is a limiting value.

At the same time, make a difference between the rotational speed n ^* given by the motor controller 5 and the rotational speed n output by the position and speed calculation module 9 to obtain Δn, which is input to the rotational speed adjustment module 11, which is a PI with limiter link, the expression is:

Among them, k _p is the proportional gain of the speed regulation module 11; _ki is the integral gain of the speed regulation module 11; z is the z transformation operator; sgn() is the sign function; i _qLim is the limit value.

The output of the rotational speed adjustment module 11 is the given i _q ^* of the q-axis current, and the difference between it and the i _q output by the abc/dq0 module 10 is obtained to obtain Δi _q , which is input to the q-axis current adjustment module 12, and the q-axis The current regulation module 12 is a PI link, and has the functions of amplitude limiting and per unit at the same time. The range of u _q ^* output by the q-axis current regulation module 12 is limited to 0-1. Its expression is:

Wherein, U _dc is the DC bus voltage sampled by the aforementioned voltage sensor 8; k _p is the proportional gain of the q-axis current regulation module 12; k _i is the integral gain of the q-axis current regulation module 12; z is the z transformation operator; sgn() is a sign function; u _dLim is a limiting value.

In the zero-sequence current suppression loop, the difference between the given i ₀ ^* and the i ₀ output by the abc/dq0 module 10 is obtained to obtain Δi ₀ , which is input to the hybrid controller module 16, and the interior of the hybrid controller module 16 The flow chart is shown in Figure 3.

As shown in FIG. 3 , the hybrid controller module 16 includes a proportional link and a second-order generalized integrator, which takes Δi ₀ as input and multiplies the positive feedback formed by f(s), and takes ω ₀ as the synchronous reference frequency of f(s) , get the suppressed output u _r , the expression is:

ur=f(s)Δi ₀

f(s) is a second-order generalized integrator, used to adjust the zero-sequence harmonic components, the expression is:

Among them, S is a complex variable; ω ₀ is the fundamental electrical angular frequency, and k is an adjustable parameter.

While the above zero-sequence current adjustment is in progress, multiply Δi ₀ by k _p of the proportional link to obtain the dynamic response output u _p , the calculation formula is:

u _p =k _p Δi ₀

k _p is the proportional gain of the proportional link, which is used to improve the dynamic response of the suppression method.

Add u _r output by f(s) and u _p output by k _p , and do business with U _dc input to the controller to get the zero-sequence voltage output u ₀ ^* after per unit, u ₀ after per unit ^*The output range is 0~1. In this way, a zero-axis current closed loop can be formed, and the zero-sequence voltage output u ₀ ^* is constantly generated to compensate the 3 times harmonic of the back EMF.

U _d ^* output from the d-axis current regulator module 13, u _q ^* output from the q-axis current regulator module 12, u ₀ ^* output from the hybrid control regulator module 16, and the rotor position output from the position and speed calculation module 9 The angle θ is commonly input to the dq0/αβ0 module 14, after being transformed by the dq0/αβ0 module 14, u _α , u _β , u ₀ are output, and the output u _α , u _β , u ₀ are input to the SVPWM module without common-mode voltage middle. Since the two two-level inverters I1 and II2 use 12 IGBT switching devices, the motor controller 5 needs to output 12 channels of PWM waves to drive the two-level inverters I1 and II2 to operate. The specific no-common-mode voltage SVPWM module space vector distribution diagram is shown in Fig. 4 .

As shown in Figure 4, under the two-phase stationary coordinate system αβ0, the open-winding permanent magnet motor system structure can generate a total of 64 vectors, in which HJLNQS and O will not generate common-mode voltage at any time, so there will be no Zero-sequence voltage causes zero-sequence current, and other space vectors will generate common-mode voltage, resulting in zero-sequence current. Therefore, these vector positions at HJLNQS and O are selected to form SVPWM modulation.

The PWM1-6 and PWM7-12 output by the SVPWM module 15 without common mode voltage are respectively input into two two-level inverters I1 and two-level inverters II2 to drive 12 switching devices S ₁ -S _6. S ₁ '-S ₆ ', so as to drive the motor to run.

The above steps are repeated according to the sampling frequency of the system current, which is to realize zero-sequence current suppression and make the motor run in a double closed-loop environment.

Next, we simulate and debug the motor system in this embodiment, and the relevant parameters of the motor are shown in Table 1:

Table 1

Figure 5 is the voltage waveform when there is no back EMF zero-sequence harmonic, and Figure 6 is the voltage waveform when there is back EMF zero-sequence harmonic. It can be seen that due to the adopted SVPWM modulation strategy, there is no common-mode voltage at any time, and in the above two cases, the common-mode voltage is zero.

Figure 7 shows the current waveform when there is no back EMF zero-sequence harmonic; Figure 8 shows the current waveform when there is back-EMF zero-sequence harmonic. It can be seen that the zero-sequence current i ₀ in Fig. 7 is zero, and the sine degree of the A-phase current _{i a} is relatively high. There is a zero-sequence current i ₀ component in Fig. Potential zero-sequence harmonics caused. The high harmonic content of the system will inevitably affect the stable operation of the motor drive system.

Fig. 9 is the voltage and current waveform after adopting the zero-sequence current suppression strategy proposed by the present invention. It can be seen that with the no-common-mode voltage modulation strategy, the dual inverter does not generate a common-mode voltage, but due to the existence of back-EMF zero-sequence harmonics, a zero-sequence current component will be generated. After adopting the zero-sequence current suppression strategy proposed by the present invention, the sine degree of the phase current is greatly improved, because the zero-sequence current is basically suppressed to zero under the action of the suppression strategy, so that the output quality of the phase current is no longer affected.

It can be seen from the simulation results that the zero-sequence current suppression strategy adopted in the present invention not only reduces the hardware cost of the system, but also reduces the complexity of algorithm implementation on the basis of ensuring obvious suppression effect, and can make the motor drive system efficient and stable running.

The above-mentioned embodiments are only for illustrating the technical concept and characteristics of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (5)

1. A rare-earth permanent magnet motor control system that suppresses zero-sequence current, is characterized in that, comprises two-level inverter I (1), two-level inverter II (2), winding open type rare-earth permanent magnet motor control system A magnetic brushless motor (3), a power supply (4), a motor controller (5), a position sensor (6), a current sensor (7) and a voltage sensor (8), and the motor controller (5) respectively passes the position The sensor (6), the current sensor (7) are connected to the open-winding less rare earth permanent magnet brushless motor (3), and the voltage output terminal of the power supply (4) is connected to the motor controller (5) through the voltage sensor (8). ) connection, the signal output terminal of the motor controller (5) is connected with the two-level inverter I (1) and the two-level inverter II (2), and the two-level inverter I (1), the output terminals of the two-level inverter II (2) are all connected to the open-winding less-rare-earth permanent magnet brushless motor (3); Wherein, the motor controller (5) includes a position and speed calculation module (9), an abc/dq0 module (10), a dq0/αβ0 module (14), a common-mode voltage-free SVPWM module (15), and a speed regulation module ( 11), the d-axis current regulation module (13), the q-axis current regulation module (12) and the hybrid controller module (16), the hybrid controller module (16) includes a proportional link and a second-order generalized integrator, the The second-order generalized integrator is used to adjust the zero-sequence harmonic component, and the proportional link is used to improve the dynamic response of the zero-sequence current suppression method. 2. a kind of rare-earth permanent magnet motor control system that suppresses zero-sequence current according to claim 1, is characterized in that, described power supply (4) is DC power supply, and described two-level inverter 1 (1), the input terminals of the two-level inverter II (2) are electrically connected respectively, and supply power to the two-level inverter I (1) and the two-level inverter II (2) at the same time. 3. a kind of rare earth permanent magnet motor control system that suppresses zero-sequence current according to claim 1, is characterized in that, described two-level inverter I (1) and two-level inverter II (2 ) are all three bridge arm structures, and each bridge arm is composed of two IGBT switching devices and reverse diodes connected in parallel with them respectively, and the 6 terminals of the open-winding less rare earth permanent magnet brushless motor (3) are respectively connected to the The two-level inverter I(1) is connected to the output terminals of the six bridge arms of the two-level inverter II(2). 4. a kind of rare-earth permanent magnet motor control system that suppresses zero-sequence current according to claim 3, is characterized in that, described motor controller (5) outputs the position signal of position sensor (6), current sensor ( 7) The detected three-phase phase current and the bus voltage detected by the voltage sensor (8) are used as input terminals, and 12 paths of PWM signals are synthesized by the motor controller (5), which are respectively connected with the two-level inverter I (1 ), signal connection of 12 IGBT switching devices of the two-level inverter II (2). 5. A kind of rare-earth permanent magnet motor control system that suppresses zero-sequence current according to claim 4, is characterized in that, the output terminal of the current sensor (7) is connected with the input terminal of the abc/dq0 module (10) , the output terminals of the abc/dq0 module (10) are respectively connected to the input terminals of the d-axis current regulation module (13), the q-axis current regulation module (12), and the hybrid controller module (16); the voltage sensor (8) The output terminals are respectively connected to the input terminals of the d-axis current regulation module (13) and the q-axis current regulation module (12); the output terminal of the position sensor (6) is connected to the input terminal of the position and speed calculation module (9), and the The output ends of the position and speed calculation module (9) are respectively connected to the input ends of the speed regulation module (11), the hybrid controller module (16), and the dq0/αβ0 module (14); the speed regulation module (11) is connected to the The q-axis current regulation module (12) is connected to the input end; the output end of the dq0/αβ0 module (14) is connected to the input end of the SVPWM module (15) without common-mode voltage, and the signal of the SVPWM module (15) without common-mode voltage The output ends are connected to the IGBT switching devices of the two-level inverter I(1) and the two-level inverter II(2) respectively.