A method for suppressing torque ripple of a variable flux reluctance motor

Abstract

The present invention discloses a method for suppressing torque pulsation of a variable flux reluctance motor. The optimal harmonic current calculation link includes the analysis of the offline torque constraint equation and the update of the online current harmonic reference value to ensure good torque pulsation suppression performance under different load conditions; the harmonic current extraction link is to extract the orthogonal amplitude of the third current harmonic to achieve the separation of the DC component and the harmonic component in the actual current; the harmonic current control link is to control the orthogonal amplitude of the third current harmonic, rather than the amplitude and phase angle, to achieve zero-static tracking of the current harmonic. Through the above links, the present invention can effectively suppress the torque pulsation of the variable flux reluctance motor. The present invention injects the third current harmonic into the integrated winding formed by connecting the armature winding and the excitation winding in parallel to suppress the non-commutation torque pulsation, eliminates the torque pulsation existing in the sine wave driven variable flux reluctance motor, and effectively reduces the torque pulsation of the variable flux reluctance motor.

Description

Technical Field

[0001] The invention belongs to the field of motor control, and in particular is a method for suppressing torque pulsation of a variable flux reluctance motor. Background Art

[0002] The variable flux reluctance motor is a new type of electrically excited double-pole motor. Its armature winding and excitation winding are both wound on the stator teeth, and the rotor is made of multiple layers of silicon steel sheets. It has the advantages of strong structure, good heat dissipation performance, wide speed regulation range and low production cost. It has good application prospects in the fields of electric vehicles and rail transportation.

[0003] The torque pulsation problem is very important for the smooth operation of the motor. Under normal circumstances, the electrically excited double-pole motor adopts control strategies based on square wave drive such as three-phase three-state, three-phase six-state and three-phase nine-state, which leads to obvious torque pulsation problems in the commutation area of ​​the motor. In order to solve the commutation torque pulsation problem, the existing technology can solve the commutation torque pulsation problem and improve the torque output capacity of the motor by connecting the armature winding and the excitation winding in parallel into an integrated winding and passing a phase current containing a DC component and a sine wave component into the integrated winding. However, due to the limitation of the second harmonic of the back electromotive force, the motor still has a large torque pulsation in the non-commutation area, and there is non-commutation torque pulsation.

[0004] The harmonic injection method is a common method for suppressing non-commutated torque pulsation by allowing the average torque fluctuation to offset the original torque pulsation. In the existing harmonic injection technology, the document with application number 202111547848.2 discloses a method for suppressing torque pulsation of a permanent magnet synchronous motor. This method does not change the magnetic field of the permanent magnet, and eliminates torque pulsation by injecting current harmonics only in the armature winding. The document with application number 202011618514.5 discloses a method for suppressing torque pulsation of an electrically excited double-pole motor with a 12 / 10 pole structure. This method does not change the sinusoidal drive mode of the armature winding, and reduces torque pulsation by injecting current harmonics only in the excitation winding. However, under the condition that the armature winding and the excitation winding of the variable flux reluctance motor are connected in parallel, the current harmonics cannot be injected only into the armature winding or only into the excitation winding, but the current harmonics need to be injected into the integrated winding. Therefore, suppressing the torque ripple of variable flux reluctance motor by harmonic injection method is still an open research issue. Summary of the invention

[0005] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a method for suppressing torque pulsation of a variable flux reluctance motor.

[0006] The technical solution of the present invention to solve the technical problem is to provide a method for suppressing torque pulsation of a variable flux reluctance motor, characterized in that the method comprises the following steps:

[0007] Step 1: Based on the finite element simulation results of the variable flux reluctance motor model, the phase self-inductance of the integrated winding formed by connecting the armature winding and the excitation winding in parallel is analyzed by Fourier harmonics, and the inductance equation is expressed as the DC component L 0 , fundamental component L 1 , second harmonic component L 2 , the third harmonic component L 3 And the fourth harmonic component L 4 superimposed form;

[0008] Step 2: transform the current equation with the third current harmonic in the rotating coordinate system into the stationary coordinate system; then, in the stationary coordinate system, bring the current equation with the third current harmonic in the stationary coordinate system and the inductance equation in step 1 into the basic torque equation, analyze the influence of injecting the third current harmonic in the integrated winding on the torque pulsation, and then establish the constraint equation of the third-order torque pulsation; then solve the constraint equation of the third-order torque pulsation to obtain the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value 0sin-ref The amplitude of the cosine component of the third current harmonic of the 0-axis current reference value is i 0cos-ref ;

[0009] Step 3: Actual current i of dq0 axis d 、i q 、i 0 The output is obtained by coordinate transformation, and the output includes DC component and harmonic component. Then the DC component is extracted by low-pass filter. The DC component is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of the dq0 axis. dsin 、i qsin 、i 0sin The amplitude of the cosine component of the third harmonic of the actual current of the dq0 axis is i dcos 、i qcos 、i 0cos ; Then the actual current i through the dq0 axis d 、i q 、i 0 Subtract the sine component and cosine component of the third current harmonic of the actual current of the dq0 axis respectively, and obtain the DC component i of the actual current of the dq0 axis dF 、i qF 、i 0F ;

[0010] Step 4: Implement i through proportional-integral controller dsin 、i qsin 、i 0sin The amplitude i of the sinusoidal component of the third harmonic of the dq0 axis current reference value dsin-ref 、i qsin-ref 、i0sin-ref Accurate tracking and implementation of dcos 、i qcos 、i 0cos The amplitude i of the cosine component of the third harmonic of the dq0 axis current reference value dcos-ref 、i qcos-ref 、i 0cos-ref Accurately track the third voltage harmonic reference value u of the dq0 axis dh-ref 、u qh-ref 、u 0h-ref ; At the same time, the proportional integral controller is used to realize i dF 、i qF 、i 0F The DC component i of the dq0 axis current reference value dF-ref 、i qF-ref 、i 0F-ref Accurately track the DC component u of the voltage reference value of the dq0 axis dF-ref 、u qF-ref 、u 0F-ref ; Then by dh-ref 、u qh-ref 、u 0h-ref and u dF-ref 、u qF-ref 、u 0F-ref Add the corresponding values ​​to get the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref .

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention injects the third harmonic current into the integrated winding formed by connecting the armature winding and the excitation winding in parallel to suppress the non-commutation torque pulsation. Compared with the sinusoidal wave driving method without the injection of the third harmonic current in the integrated winding, the torque pulsation existing in the sinusoidal wave driven variable flux reluctance motor is eliminated, and the torque pulsation of the variable flux reluctance motor is effectively reduced.

[0013] (2) In the present invention, the optimal harmonic current calculation link includes the analysis of the offline torque constraint equation and the update of the online current harmonic reference value to ensure good torque pulsation suppression performance under different load conditions; the harmonic current extraction link is to extract the amplitude i of the sinusoidal component of the third current harmonic of the actual current dsin 、i qsin 、i 0sin and the amplitude of the cosine component i dcos 、i qcos 、i 0cos , to achieve the separation of DC component and harmonic component in the actual current; the harmonic current control link is to control the amplitude of the sinusoidal component of the third current harmonic of the actual current idsin 、i qsin 、i 0sin and the amplitude of the cosine component i dcos 、i qcos 、i 0cos , rather than amplitude and phase angle, to achieve zero-static-error tracking of current harmonics. Through the above links, the present invention can effectively suppress the torque pulsation of the variable flux reluctance motor.

[0014] (3) The present invention analyzes the phase self-inductance of the integrated winding rather than the separate armature winding or field winding.

[0015] (4) The present invention 0sin-ref and i 0cos-ref It can be expressed by the inductance and the DC component of the actual current. Good torque pulsation suppression performance can adapt to different load conditions and adapt to changes in motor load.

[0016] (5) The present invention controls the DC component and harmonic component of the actual current separately, thus avoiding the mutual influence between the two.

[0017] (6) The present invention controls the amplitude i of the sinusoidal component of the third harmonic of the actual current through a proportional-integral controller dsin 、i qsin 、i 0sin and the amplitude of the cosine component i dcos 、i qcos 、i 0cos The steady-state error of the harmonic components of the actual current is theoretically eliminated by controlling the amplitude and phase angle instead of the amplitude and phase angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the topological structure of a 6-slot 4-pole variable flux reluctance motor according to Embodiment 1 of the present invention;

[0019] Figure 2 Schematic diagram of the topological structure of the variable flux reluctance motor driver according to Embodiment 1 of the present invention;

[0020] Figure 3 is a system block diagram of the method of the present invention;

[0021] Figure 4 This is a finite element simulation waveform diagram of the integrated winding phase self-inductance of Example 1 of the present invention;

[0022] Figure 5 This is a Fourier spectrum analysis diagram of the phase self-inductance of the integrated winding of Example 1 of the present invention;

[0023] Figure 6 is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of the 0-axis in the first embodiment of the present invention 0sinand the amplitude of the cosine component i 0cos Extraction block diagram;

[0024] Figure 7 is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of the 0-axis in the first embodiment of the present invention 0sin and the amplitude of the cosine component i 0cos Control block diagram of

[0025] Figure 8 This is a diagram of the experimental results before using this method in Example 1 of the present invention;

[0026] Fig. 9 This is a diagram of the experimental results of Example 1 of the present invention after adopting this method. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the claims of the present invention.

[0028] The present invention provides a method for suppressing torque pulsation of a variable flux reluctance motor (hereinafter referred to as the method), characterized in that the method comprises the following steps:

[0029] Step 1: Based on the finite element simulation results of the variable flux reluctance motor model (this embodiment uses the ANSYS simulation software), the phase self-inductance of the integrated winding formed by connecting the armature winding and the excitation winding in parallel is analyzed by Fourier harmonics, and the inductance equation is expressed as the DC component L 0 , fundamental component L 1 , second harmonic component L 2 , the third harmonic component L 3 And the fourth harmonic component L 4 superimposed form;

[0030] Preferably, in step 1, the inductance equation is expressed as:

[0031]

[0032] In formula (1), L a , L b , L c is the self-inductance of phases a, b, and c; L 0 , L 1 , L 2 , L 3 , L 4 is the DC component, fundamental component, second harmonic component, third harmonic component and fourth harmonic component of the phase self-inductance, obtained by Fourier analysis of the finite element simulation results in step 1; θ e The electrical angle.

[0033] Step 2: Convert the current equation with the third current harmonic in the rotating coordinate system to the stationary coordinate system through the inverse Parker transformation; then, in the stationary coordinate system, bring the current equation with the third current harmonic in the stationary coordinate system and the inductance equation in step 1 into the basic torque equation, analyze the influence of injecting the third current harmonic in the integrated winding on the torque pulsation, and then establish the constraint equation of the third-order torque pulsation; then solve the constraint equation of the third-order torque pulsation to obtain the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value 0sin-ref The amplitude of the cosine component of the third current harmonic of the 0-axis current reference value is i 0cos-ref ;

[0034] Preferably, in step 2, the current equation with the third current harmonic in the rotating coordinate system is:

[0035]

[0036] In formula (2), i d-ref 、i q-ref 、i 0-ref are the current reference values ​​of dq0 axis (i.e. d axis, q axis, 0 axis) respectively; i dF-ref 、i qF-ref 、i 0F-ref are the DC components of the dq0 axis current reference values ​​respectively; θ e is the electrical angle;

[0037] Preferably, in step 2, the current equation with the third current harmonic in the stationary coordinate system is:

[0038]

[0039] In formula (3), i a 、i b 、i c is the three-phase current;

[0040] Preferably, in step 2, the basic torque equation is:

[0041]

[0042] In formula (4), T e is the electromagnetic torque output by the motor; P is the number of rotor poles.

[0043] Preferably, in step 2, the constraint equation of the third-order torque ripple is:

[0044]

[0045] Preferably, in step 2, by solving equation (5), the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value is obtained. 0sin-ref and the amplitude of the cosine component i0cos-ref , as shown in formula (6):

[0046]

[0047] In formula (6), i dsin-ref 、i qsin-ref 、i 0sin-ref is the amplitude of the sinusoidal component of the third current harmonic of the dq0 axis current reference value; i dcos-ref 、i qcos-ref 、i 0cos-ref is the amplitude of the cosine component of the third current harmonic of the dq0 axis current reference value; i qF-ref 、i 0F-ref are the DC components of the q-axis and 0-axis current reference values ​​respectively;

[0048] From formula (6), we can know that the amplitude i of the sinusoidal component of the third harmonic of the dq0 axis current reference value is dsin-ref 、i qsin-ref 、i 0sin-ref and the amplitude of the cosine component i dcos-ref 、i qcos-ref 、i 0cos-ref The DC component L 0 , fundamental component L 1 , second harmonic component L 2 , the third harmonic component L 3 , the fourth harmonic component L 4 And the DC component i of the q-axis current reference value qF-ref and the DC component i of the 0-axis current reference value 0F-ref express.

[0049] Step 3: Actual current i of dq0 axis d 、i q 、i 0 The output is obtained by coordinate transformation, and the output includes DC component and harmonic component. Then the DC component is extracted by low-pass filter. The DC component is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of the dq0 axis. dsin 、i qsin 、i 0sin The amplitude of the cosine component of the third harmonic of the actual current of the dq0 axis is i dcos 、i qcos 、i 0cos ; Then the actual current i through the dq0 axis d 、i q 、i 0 Subtract the sine component and cosine component of the third current harmonic of the actual current of the dq0 axis respectively, and obtain the DC component i of the actual current of the dq0 axis dF 、i qF 、i0F ;

[0050] Preferably, in step 3, taking the 0 axis as an example, the coordinate transformation is expressed as:

[0051]

[0052] Similarly, the coordinate transformation of the dq axis can be obtained.

[0053] Preferably, in step 3, taking axis 0 as an example, the actual current i of axis 0 is 0 Subtract the sinusoidal component i of the third harmonic of the actual current of the 0 axis 0sin sin(3θ e ) and cosine component i 0cos cos(3θ e ), and obtain the DC component i of the actual current of axis 0 0F :

[0054] i 0F =i 0 -i 0sin sin(3θ e )-i 0cos cos(3θ e ) (8)

[0055] Similarly, the DC component i of the actual current in the dq axis can be obtained dF 、i qF .

[0056] Step 4: Implement i through proportional-integral controller dsin 、i qsin 、i 0sin The amplitude i of the sinusoidal component of the third harmonic of the dq0 axis current reference value dsin-ref 、i qsin-ref 、i 0sin-ref Accurate tracking and implementation of dcos 、i qcos 、i 0cos The amplitude i of the cosine component of the third harmonic of the dq0 axis current reference value dcos-ref 、i qcos-ref 、i 0cos-ref Accurately track the third voltage harmonic reference value u of the dq0 axis dh-ref 、u qh-ref 、u 0h-ref ; At the same time, the proportional integral controller is used to realize i dF 、i qF 、i 0F The DC component i of the dq0 axis current reference value dF-ref 、i qF-ref 、i 0F-refAccurately track the DC component u of the voltage reference value of the dq0 axis dF-ref 、u qF-ref 、u 0F-ref ; Then by dh-ref 、u qh-ref 、u 0h-ref and u dF-ref 、u qF-ref 、u 0F-ref Add the corresponding values ​​to get the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref .

[0057] Preferably, in step 4, taking axis 0 as an example, the voltage reference value is expressed as:

[0058]

[0059] In formula (9), K P0F , K P0cos , K P0sin is the proportional gain of the proportional-integral controller, K I0F , K I0cos , K I0sin is the integral gain of the proportional-integral controller, u 0F-ref is the DC component of the 0-axis voltage reference value, u 0sin-ref and u 0cos-ref is the amplitude of the sine component of the third voltage harmonic of the 0-axis voltage reference value and the amplitude of the cosine component of the third voltage harmonic of the 0-axis voltage reference value;

[0060] Similarly, the voltage reference value u of the dq axis can be obtained d-ref and u q-ref .

[0061] Preferably, by setting the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref The input is then fed into a modulation module of an existing motor control system, thereby ultimately achieving suppression of the torque pulsation of the variable flux reluctance motor.

[0062] Example 1

[0063] The variable flux reluctance motor used in this embodiment is a 6-slot 4-pole variable flux reluctance motor. Figure 2 The motor includes a stator and a rotor. The armature winding and the excitation winding of the motor are both located on the stator side. In actual operation, the armature winding and the excitation winding are usually connected in parallel as an integrated winding to improve the torque output capacity of the motor.

[0064] The variable flux reluctance motor driver used in this embodiment is composed of two three-phase inverters with a common DC bus. The left end of the integrated winding is connected to the neutral point of the three bridge arms of the left inverter, and the right end of the integrated winding is connected to the neutral point of the three bridge arms of the right inverter. Figure 3 shown.

[0065] The torque ripple suppression method of variable flux reluctance motor is as follows Figure 3 As shown, it includes three parts: optimal harmonic current calculation, harmonic current extraction and harmonic current control. Among them, the optimal harmonic current calculation is step 1 and step 2, the harmonic current extraction is step 3, and the harmonic current control is step 4, which specifically includes the following steps:

[0066] Step 1: According to Figure 4 The finite element simulation results of the variable flux reluctance motor model in the embodiment (ansys simulation software is used in this embodiment), the Fourier harmonic analysis of the phase self-inductance of the integrated winding is performed (the analysis results are shown in FIG. Figure 5 As shown), where the DC component of the phase self-inductance L 0 is 0.03H, the fundamental component L 1 is 0.024H, the second harmonic component L 2 is 0.0024H, the third harmonic component L 3 is 0.0004H, the fourth harmonic component L 4 is 0.0016H. Since the high-order harmonic component of the integrated winding phase self-inductance is very small, the inductance equation is expressed as the DC component L 0 , fundamental component L 1 , second harmonic component L 2 , the third harmonic component L 3 And the fourth harmonic component L 4 superimposed form;

[0067] Step 2: Convert the current equation with the third current harmonic in the rotating coordinate system to the stationary coordinate system through the inverse Parker transformation; then, in the stationary coordinate system, bring the current equation with the third current harmonic in the stationary coordinate system and the inductance equation in step 1 into the basic torque equation, analyze the influence of injecting the third current harmonic in the integrated winding on the torque pulsation, and then establish the constraint equation of the third-order torque pulsation; then solve the constraint equation of the third-order torque pulsation to obtain the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value 0sin-ref and the amplitude of the cosine component i 0cos-ref ;

[0068] Step 3: Actual current i of dq0 axis d 、i q 、i 0The output is obtained by coordinate transformation, and the output includes DC component and harmonic component. Then the DC component is extracted by low-pass filter. The DC component is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of the dq0 axis. dsin 、i qsin 、i 0sin The amplitude of the cosine component of the third harmonic of the actual current of the dq0 axis is i dcos 、i qcos 、i 0cos , the harmonic current extraction process is as follows Figure 6 ; Then the actual current i through the dq0 axis d 、i q 、i 0 Subtract the sine component and cosine component of the third current harmonic of the actual current of the dq0 axis respectively, and obtain the DC component i of the actual current of the dq0 axis dF 、i qF 、i 0F ;

[0069] Step 4: Implement i through proportional-integral controller dsin 、i qsin 、i 0sin The amplitude i of the sinusoidal component of the third harmonic of the dq0 axis current reference value dsin-ref 、i qsin-ref 、i 0sin-ref Accurate tracking and implementation of dcos 、i qcos 、i 0cos The amplitude i of the cosine component of the third harmonic of the dq0 axis current reference value dcos-ref 、i qcos-ref 、i 0cos-ref Accurately track the third voltage harmonic reference value u of the dq0 axis dh-ref 、u qh-ref 、u 0h-ref ,like Figure 7 As shown; at the same time, the proportional integral controller is used to realize i dF 、i qF 、i 0F The DC component i of the dq0 axis current reference value dF-ref 、i qF-ref 、i 0F-ref Accurately track the DC component u of the voltage reference value of the dq0 axis dF-ref 、u qF-ref 、u 0F-ref ; Then by dh-ref 、u qh-ref 、u 0h-ref and u dF-ref 、u qF-ref 、u 0F-refAdd the corresponding values ​​to get the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref .

[0070] Depend on Figure 8 and Fig. 9 It can be seen that the maximum torque before the method proposed by the present invention is 0.538Nm, the minimum torque is 0.224Nm, the average torque is 0.381Nm, and the torque ripple is 82.6%. The maximum torque after the method proposed by the present invention is 0.443Nm, the minimum torque is 0.307Nm, the average torque is 0.375Nm, and the torque ripple is 36.3%. The present invention reduces the torque ripple of the variable flux reluctance motor by 56% by injecting current harmonics into the integrated winding.

[0071] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A method for suppressing torque pulsation of a variable flux reluctance motor, characterized in that: The method comprises the following steps: Step 1, according to the finite element simulation results of the variable flux reluctance motor model, the phase self-inductance of the integrated winding formed by connecting the armature winding and the excitation winding in parallel is analyzed by Fourier harmonics, and the inductance equation is expressed as a superposition of a DC component L0, a fundamental component L1, a second harmonic component L2, a third harmonic component L3 and a fourth harmonic component L4; Step 2: transform the current equation with the third current harmonic in the rotating coordinate system into the stationary coordinate system; then, in the stationary coordinate system, bring the current equation with the third current harmonic in the stationary coordinate system and the inductance equation in step 1 into the basic torque equation, analyze the influence of injecting the third current harmonic in the integrated winding on the torque pulsation, and then establish the constraint equation of the third-order torque pulsation; then solve the constraint equation of the third-order torque pulsation to obtain the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value 0sin-ref The amplitude of the cosine component of the third current harmonic of the 0-axis current reference value is i 0cos-ref ; Step 3: Actual current i of dq0 axis d 、i q , i0 obtains the output through coordinate transformation, which includes DC component and harmonic component; then the DC component is extracted through low-pass filter, and the DC component is the amplitude i of the sinusoidal component of the third current harmonic of the actual current of dq0 axis dsin 、i qsin 、i 0sin The amplitude of the cosine component of the third harmonic of the actual current of the dq0 axis is i dcos 、i qcos 、i 0cos ; Then the actual current i through the dq0 axis d 、i q , i0 respectively subtract the sine component and cosine component of the third current harmonic of the actual current of the dq0 axis, and obtain the DC component i of the actual current of the dq0 axis dF 、i qF 、i 0F ; Step 4: Implement i through proportional-integral controller dsin 、i qsin 、i 0sin The amplitude i of the sinusoidal component of the third harmonic of the dq0 axis current reference value dsin-ref 、i qsin-ref 、i 0sin-ref Accurate tracking and implementation of dcos 、i qcos 、i 0cos The amplitude i of the cosine component of the third harmonic of the dq0 axis current reference value dcos-ref 、i qcos-ref 、i 0cos-ref Accurately track the third voltage harmonic reference value u of the dq0 axis dh-ref 、u qh-ref 、u 0h-ref ; At the same time, the proportional integral controller is used to realize i dF 、i qF 、i 0F The DC component i of the dq0 axis current reference value dF-ref 、i qF-ref 、i 0F-ref Accurately track the DC component u of the voltage reference value of the dq0 axis dF-ref 、u qF-ref 、u 0F-ref ; Then by dh-ref 、u qh-ref 、u 0h-ref and u dF-ref 、u qF-ref 、u 0F-ref Add the corresponding values ​​to get the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref .

2. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 1, the inductance equation is expressed as: In formula (1), L a , L b , L c is the phase self-inductance of phases a, b, and c; L0, L1, L2, L3, and L4 are the DC component, fundamental component, second harmonic component, third harmonic component, and fourth harmonic component of the phase self-inductance, which are obtained by Fourier analysis of the finite element simulation results in step 1; θ e The electrical angle.

3. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 2, the current equation with the third current harmonic in the rotating coordinate system is: In formula (2), i d-ref 、i q-ref 、i 0-ref are the reference values ​​of dq0 axis current respectively; i dF-ref 、i qF-ref 、i 0F-ref are the DC components of the dq0 axis current reference values ​​respectively; θ e The electrical angle.

4. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 2, the current equation with the third current harmonic in the stationary coordinate system is: In formula (3), i a 、i b 、i c is the three-phase current.

5. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 2, the constraint equation for the third-order torque ripple is:

6. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 5, characterized in that: In step 2, by solving equation (5), the amplitude i of the sinusoidal component of the third current harmonic of the 0-axis current reference value is obtained: 0sin-ref and the amplitude of the cosine component i 0cos-ref , as shown in formula (6): In formula (6), i dsin-ref 、i qsin-ref 、i 0sin-ref is the amplitude of the sinusoidal component of the third current harmonic of the dq0 axis current reference value; i dcos-ref 、i qcos-ref 、i 0cos-ref is the amplitude of the cosine component of the third current harmonic of the dq0 axis current reference value; i qF-ref 、i 0F-ref They are the DC components of the q-axis and 0-axis current reference values ​​respectively.

7. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 3, taking the 0 axis as an example, the coordinate transformation is expressed as: Similarly, the coordinate transformation of the dq axis can be obtained.

8. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 3, taking axis 0 as an example, the actual current i0 of axis 0 minus the sinusoidal component i of the third harmonic of the actual current of axis 0 is obtained. 0sin sin(3θ e ) and cosine component i 0cos cos(3θ e ), and obtain the DC component i of the actual current of axis 0 0F : i 0F =i0-i 0sin sin(3θ e )-i 0cos cos(3θ e ) (8) Similarly, the DC component i of the actual current in the dq axis can be obtained dF 、i qF .

9. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: In step 4, taking axis 0 as an example, the voltage reference value is expressed as: In formula (9), K P0F , K P0cos , K P0sin is the proportional gain of the proportional-integral controller, K I0F , K I0cos , K I0sin is the integral gain of the proportional-integral controller, u 0F-ref is the DC component of the 0-axis voltage reference value, u 0sin-ref and u 0cos-ref is the amplitude of the sine component of the third voltage harmonic of the 0-axis voltage reference value and the amplitude of the cosine component of the third voltage harmonic of the 0-axis voltage reference value; Similarly, the voltage reference value u of the dq axis can be obtained d-ref and u q-ref .

10. The method for suppressing torque ripple of a variable flux reluctance motor according to claim 1, characterized in that: By setting the voltage reference value u of the dq0 axis d-ref 、u q-ref 、u 0-ref The input is then fed into a modulation module of an existing motor control system, thereby ultimately achieving suppression of the torque pulsation of the variable flux reluctance motor.

Images