Current reconstruction method for 30° phase belt angle dual three-phase permanent magnet synchronous motor

Abstract

30° phase belt angle double three-phase permanent magnet synchronous motor current reconstruction method solves the problems of existing method unified SVM reference voltage operation complexity, switch vector needs to be recombined calculation, reconstruction sector planning complexity, belongs to the field of motor drive. The invention simplifies the vector combination, obtains the simplified sector, and judges the position of the reference voltage vector based on the current sector of the two sets of three-phase windings, shifts the carrier of the second set of three-phase windings, constructs the sampling switch combination, flexibly configures the sampling time according to the sector position of the reference voltage, samples at four zero vectors respectively, and obtains four groups of sampling currents with six-phase current information; based on the current reconstruction expression under different sectors, the six-phase current reconstruction is completed; the reconstructed current is sent to the VSD control loop, the given voltage generated by the VSD-2DQ equivalent transformation is calculated by single step to obtain two groups of three-phase SVM given value, and finally six-phase bridge arm driving signal is generated.

Description

TECHNICAL FIELD

[0001] The application relates to a current reconstruction method of a 30-degree phase band angle dual-three-phase permanent magnet synchronous motor, and belongs to the field of motor driving. BACKGROUND

[0002] For aerospace, electric vehicles and other electric drive systems sensitive to vibration, efficiency and volume, there is a demand for high power density integration. Zero phase shift dual-three-phase permanent magnet synchronous motor (ZPS-DTP-PMSM) has the advantages of low back electromotive force, small single-phase current, high output power, high running efficiency, low manufacturing design difficulty, etc., and is currently the main application scheme for high power density integration in the field of electric vehicles.

[0003] The traditional DTP-PMSM closed-loop speed regulation system needs at least four current sensors to complete the six-phase current information acquisition and loop operation. Multiple current Hall sampling will increase the volume and cost of the controller, and the calibration deviation between different sensors will cause different bias and phase errors, which will reduce the system control performance. The phase current reconstruction technology is an effective means to reduce the number of sensors and improve the system performance. However, the traditional DTP-PMSM speed regulation system current reconstruction scheme is still based on three-phase units, and two groups of sensors are used to reconstruct two groups of three-phase currents, and the number of current sensors can be further optimized.

[0004] Due to the existence of the minimum sampling time, current reconstruction often needs to eliminate the reconstruction blind area. In order to eliminate the blind area, the traditional research method needs to add an additional compensation strategy to eliminate the current reconstruction blind area and ensure the continuity and accuracy of the current reconstruction, such as vector pulse method, pulse width shift method, state observer method, etc. The vector pulse method inserts a measurement vector at the end of the switching cycle vector to ensure normal reconstruction sampling, but this method makes the number of switching actions in one switching cycle greater than 1, increases the switching loss, and reduces the system efficiency; the pulse width shift method changes the symmetric seven-segment space vector modulation (SVM) strategy to asymmetric SVM at the blind area to concentrate the blind area effective vector action time in one place to ensure normal reconstruction, but the application of asymmetric SVM will bring the system to the odd switching and its sideband harmonics, which will increase the motor vibration noise; the state observer method uses mathematical methods to design corresponding filters to fit the current waveform, which will undoubtedly increase the operation strength of the system. And the sampling points of the traditional current reconstruction scheme need to be changed according to the effective vector action time, and the switching action sequence needs to be smoothed, and the ADC sampling needs to be triggered, which has a certain complexity.

[0005] The characteristics of electromagnetic vibration noise spectrum are directly related to system switching frequency, modulation mode, topology and other factors, and how to suppress noise so that the motor drive system meets the low noise index requirement in a wide frequency band is also the main problem faced by the electric drive system. Domestic and foreign scholars have carried out extensive research on high-frequency PWM harmonic suppression technology, the main methods include: using a sine wave filter for hardware filtering, improving the fixed frequency pulse width modulation algorithm, applying carrier phase shift technology in traditional interleaved parallel topology, isolation type interleaved parallel topology and cascade H-bridge topology. But the traditional DTP-PMSM electromagnetic vibration noise suppression scheme does not consider current reconstruction, and there is further optimization space. SUMMARY

[0006] In view of the problems that the six-phase unified SVM reference voltage of the 30-degree phase belt angle DTP-PMSM is complex to calculate, the switching vector needs to be recombined, the calculation amount is large, and the reconstruction sector planning is complex, the application provides a current reconstruction method for a 30-degree phase belt angle double three-phase permanent magnet synchronous motor.

[0007] The current reconstruction method for the 30-degree phase belt angle double three-phase permanent magnet synchronous motor provided by the application comprises the following steps:

[0008] S1, uniformly planning two sets of three-phase winding space vectors of the double three-phase permanent magnet synchronous motor in the same phase space:

[0009]

[0010] Wherein, U dc is the bus voltage; S A , S B , S C , S X , S Y , S Z are six-phase bridge arm switching functions, and the values are 0, which represents that the lower tube of the bridge arm is turned on, and the value is 1, which represents that the upper tube of the bridge arm is turned on; U 1k is a space vector formed by the first set of three-phase winding ABC; U 2k is a space vector formed by the second set of three-phase winding XYZ, and k=1, 2, 3, 4, 5, 6;

[0011] Integrate the two sets of three-phase winding space vectors into the same phase space plane to obtain 12 subspaces in the phase space plane;

[0012] S2, the carrier of the second set of three-phase winding XYZ is lagged behind the first set of three-phase winding ABC by 1 / 4 switching period T s, four switch combinations corresponding to four zero voltage vectors are constructed, and two sets of three-phase windings are sampled four times under different zero voltage vectors in a switching period, so as to obtain a six-phase current reconstruction expression of the dual three-phase permanent magnet synchronous motor in each subspace; according to the position of the reference voltage vector in the phase space, the corresponding six-phase current reconstruction expression is selected to reconstruct the six-phase current of the dual three-phase permanent magnet synchronous motor.

[0013] Preferably, each subspace is surrounded by two space vectors, and each subspace includes an upper boundary region, a lower boundary region and a sector between the two; the determination method of the upper and lower boundary regions is that the time maintained by the corresponding space vectors of the two sets of sampled three-phase windings in the sector at the sampling time cannot meet the minimum sampling time;

[0014] Subspace I is surrounded by the space vectors corresponding to S A =1, S B =0 and S C =0, subspace V is surrounded by the space vectors corresponding to S X =0, S Y =1 and S Z =0, subspace IX is surrounded by the space vectors corresponding to S A =0, S B =1 and S C =0, and subspace IX is surrounded by the space vectors corresponding to S X =0, S Y =1 and S Z =0. A B C X Y Z

[0015] The judgment mode of the four sampling time points of the subspace I, V, IX and IX is as follows:

[0016] When the reference voltage vector is located in the sector, the four sampling time points are 0T s , 0.25T s , 0.5T s and 0.75T s .

[0017] When the reference voltage is located in the upper boundary region of the sector, the four sampling time points are 0T s , 0.25T s -T min , 0.5T s and 0.75T s +T min , T min ​​​​​​is the minimum sampling time;

[0018] When the reference voltage is located in the lower boundary region of the sector, the four sampling instants are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s ;

[0019] Subspace II is enclosed by the space vectors corresponding to S A =1, S B =1, S C =0 and the space vectors corresponding to S X =0, S Y =0, S Z =0; Subspace VI is enclosed by the space vectors corresponding to S A =0, S B =1, S C =1 and the space vectors corresponding to S X =0, S Y =1, S Z =0; Subspace X is enclosed by the space vectors corresponding to S A =1, S B =0, S C =1 and the space vectors corresponding to S X =0, S Y =0, S Z =1;

[0020] The judgment mode at the four sampling instants in subspaces II, VI and X is as follows:

[0021] When the reference voltage vector is located in the sector, the four sampling instants are 0T s , 0.25T s , 0.5T s , 0.75T s ;

[0022] When the reference voltage is located in the upper boundary region of the sector, the four sampling instants are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s , T min is the minimum sampling time;

[0023] When the reference voltage is located in the lower boundary region of the sector, the four sampling instants are 0T s , 0.25T s +Tmin , 0.5T s , 0.75T s -T min ;

[0024] Subspace III is enclosed by the space vectors corresponding to S A =1, S B =1, S C =0, and S X =1, S Y =1, S Z =0; Subspace VII is enclosed by the space vectors corresponding to S A =0, S B =1, S C =1, and S X =0, S Y =1, S Z =1; Subspace IX is enclosed by the space vectors corresponding to S A =1, S B =0, S C =1, and S X =1, S Y =0, S Z =1;

[0025] The judgment mode at the four sampling time instants of Subspace III, VII, and IX is as follows:

[0026] When the reference voltage vector is located in a sector, the four sampling time instants are 0T s , 0.25T s , 0.5T s , 0.75T s ;

[0027] When the reference voltage is located in the upper boundary region of a sector, the four sampling time instants are 0T s , 0.25T s +T min , 0.5T s , 0.75T s -T min , T min is the minimum sampling time;

[0028] When the reference voltage is located in the lower boundary region of a sector, the four sampling time instants are 0T s -T min , 0.25T s , 0.5T s +T min , 0.75T s ;

[0029] Subspace IV is enclosed by the space vectors corresponding to SA = 0, S B = 1, S C = 0, S X = 1, S Y = 1, S Z = 0, S A = 1, S B = 1, S C = 1, S X = 0, S Y = 1, S Z = 1, S A = 1, S B = 0, S C = 0, S X = 1, S Y = 0, S Z = 1, S

[0030] The judgment mode at the four sampling time instants of the subspaces IV, VIII and XII is as follows:

[0031] When the reference voltage vector is located in a sector, the four sampling time instants are 0T s , 0.25T s , 0.5T s , 0.75T s , respectively.

[0032] When the reference voltage is located in the upper boundary region of a sector, the four sampling time instants are 0T s -T min , 0.25T s , 0.5T s +T min , 0.75T s , respectively.

[0033] When the reference voltage is located in the lower boundary region of a sector, the four sampling time instants are 0T s , 0.25T s -T min , 0.5T s , 0.75T s +T min , respectively, T min being the minimum sampling time.

[0034] As a preferred option, a single current Hall sensor is used to sample the sum of the currents of the upper B-phase tube and the lower C-phase tube of the first set of three-phase windings ABC and the upper X-phase tube and the lower Y-phase tube of the second set of three-phase windings XYZ.

[0035] As preferred, the method of the embodiment further comprises:

[0036] S3, the reconstructed current is converted by VSD coordinate transformation to obtain torque current feedback value i q , flux linkage current feedback value i d , harmonic current feedback values i orthogonal to each other Z1 , i Z2 , respectively, and the corresponding given current is subtracted to input the current loop controller to obtain torque voltage given value u q , flux linkage voltage given value u d , harmonic voltage given value u orthogonal to each other z1 u z2 ;

[0037] According to torque voltage given value u q , flux linkage voltage given value u d , harmonic voltage given value u z1 , u z2 Two sets of three-phase winding SVM given voltage values u q1 , u q2 d1, u d2 are obtained by using VSD-2DQ equivalent transformation matrix.

[0038]

[0039] Wherein, θ represents the electrical angle of the double three-phase permanent magnet synchronous motor;

[0040] According to two sets of three-phase winding SVM given voltage values u d1 , u q1 , u d2 , u q2 , the six-phase bridge arm driving signals of the double three-phase permanent magnet synchronous motor are generated.

[0041] The beneficial effects of the present application, the present application adopts three-phase independent SVM strategy, according to the characteristics of 30° phase band angle DTP-PMSM space vector, the original high degree of freedom vector combination is simplified, the simplified sector is obtained, and the position of the reference voltage vector is judged based on the current sector of the two sets of three-phase winding; The sampling topology is modified to obtain the corresponding relationship of the sensor phase current, and the speed and position angle required for motor operation and other control quantities are collected; The carrier of the second three-phase winding XYZ is phase-shifted, the sampling switch combination is constructed, the sampling time is flexibly configured according to the sector position of the reference voltage, the reconstruction blind area is avoided, sampling is carried out at four zero vectors respectively, four groups of sampling currents with six-phase current information are obtained; The six-phase current reconstruction is completed based on the current reconstruction expression under different sectors; The reconstructed current is input into the VSD control loop to generate the given reference voltage output in the VSD coordinate system; Through VSD-2DQ equivalent transformation, two sets of three-phase SVM given values are obtained by single-step calculation, and finally six-phase bridge arm driving signals are generated. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The control block diagram of the current reconstruction method of the 30° phase belt angle DTP-PMSM, wherein θ is the electrical angle of the DTP-PMSM, ω is the rotating speed of the DTP-PMSM, N1 and N2 are the SVM sectors of the ABC winding and the XYZ winding respectively, I SAMPLE The current Hall sampling value.

[0043] Figure 2 The DTP-PMSM current reconstruction topology diagram.

[0044] Figure 3 The simplified SVM space voltage vector distribution diagram of the 30° phase belt angle DTP-PMSM.

[0045] Fig. 4(a) is a schematic diagram of the sector I sampling moment, wherein I1 is the sampling information of the winding 1 corresponding to UVW when the switching function is 000, I2 is the sampling information of the winding 1 corresponding to UVW when the switching function is 111, I3 is the sampling information of the winding 2 corresponding to UVW when the switching function is 000, and I4 is the sampling information of the winding 2 corresponding to UVW when the switching function is 111.

[0046] Fig. 4(b) is a schematic diagram of the sector II sampling moment, wherein I1 is the sampling information of the winding 1 corresponding to UVW when the switching function is 000, I2 is the sampling information of the winding 1 corresponding to UVW when the switching function is 111, I3 is the sampling information of the winding 2 corresponding to UVW when the switching function is 000, and I4 is the sampling information of the winding 2 corresponding to UVW when the switching function is 111. 21 The boundary blind area sampling moment modification schematic diagram.

[0047] Figure 5 The single current sensor sampling current and the ABCXYZ six-phase current waveform diagram.

[0048] Figure 6 The single current sensor sampling current four times per switching period diagram.

[0049] Fig. 7(a) is the ABC real phase current and the reconstructed current waveform diagram.

[0050] Fig. 7(b) is the XYZ real phase current and the reconstructed current waveform diagram.

[0051] Figure 8 The A-phase real current and the reconstructed current error. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0053] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0054] The present application will be further described below in conjunction with the drawings and specific embodiments, but not as a limitation of the present application.

[0055] In view of the problems of complex calculation of six-phase unified SVM reference voltage of 30° phase belt angle DTP-PMSM, large calculation amount of recombination of switching vectors, and complex reconstruction sector planning, the current reconstruction method of 30° phase belt angle double three-phase permanent magnet synchronous motor of the present embodiment includes:

[0056] Step 1, uniformly planning two sets of three-phase winding space vectors of double three-phase permanent magnet synchronous motor in the same phase space respectively:

[0057]

[0058] Wherein, U dc is the bus voltage; S A , S B , S C , S X , S Y , S Z are six-phase bridge arm switching functions, taking value 0 represents that the lower tube of the bridge arm is turned on, and taking value 1 represents that the upper tube of the bridge arm is turned on; U 1k is the space vector formed by the first set of three-phase winding ABC; U 2k is the space vector formed by the second set of three-phase winding XYZ, k = 1, 2, 3, 4, 5, 6;

[0059] Integrating the two sets of three-phase winding space vectors into the same phase space plane, 12 subspaces in the phase space plane are obtained, each of which is surrounded by two space vectors, and each of which includes upper and lower boundary regions and sectors therebetween; the determination method of the upper and lower boundary regions is that the time maintained by the corresponding space vectors of the two sets of three-phase windings at the sampling time within the sector cannot meet the minimum sampling time;

[0060] The present embodiment converts 64 voltage vectors into a limited combination of two independent three-phase voltage vectors in combination with the characteristics of 30° phase belt angle DTP-PMSM, and simplifies 12 sectors to obtain simplified sectors, thereby reducing the calculation amount.

[0061] Step 2, lagging the carrier of the second set of three-phase winding XYZ relative to the first set of three-phase winding ABC by 1 / 4 switching period T s, four switch combinations corresponding to the four zero voltage vectors are constructed, and the two sets of three-phase windings are sampled four times under different zero vectors in a switching period, so as to obtain a six-phase current reconstruction expression of the double three-phase permanent magnet synchronous motor in each subspace; according to the position of the reference voltage vector in the phase space, the corresponding six-phase current reconstruction expression is selected to reconstruct the six-phase current of the double three-phase permanent magnet synchronous motor. In view of the problem that the operation complexity of the reconstruction blind area avoidance method has an adverse effect on current harmonics and motor vibration, the second set of three-phase windings XYZ is phase-shifted by a carrier in this embodiment, a sampling switch combination is constructed, sampling time is flexibly configured according to the sector position of the reference voltage, and four groups of sampling currents with six-phase current information are obtained by sampling at four zero vectors;

[0062] Each subspace includes one sector and an upper boundary region and a lower boundary region of the sector;

[0063] As shown in Figure 3 , the subspace I is surrounded by the space vectors corresponding to S A =1, S B =0 and S C =0 and the space vectors corresponding to S X =1, S Y =0 and S Z =0, the subspace V is surrounded by the space vectors corresponding to S A =0, S B =1 and S C =0 and the space vectors corresponding to S X =0, S Y =1 and S Z =0, the subspace IX is surrounded by the space vectors corresponding to S A =0, S B =0 and S C =1 and the space vectors corresponding to S X =0, S Y =0 and S Z =1, the subspace II is surrounded by the space vectors corresponding to S A =1, S B =1 and S C =0 and the space vectors corresponding to S X =1, S Y =0 and S Z =0, the subspace VI is surrounded by the space vectors corresponding to S A =0, S B =1 and S C =1 and the space vectors corresponding to S X =0, S Y =1 and S Z =0, and the subspace X is surrounded by the space vectors corresponding to S A =1, SB = 0, S C = 1 corresponds to the space vector enclosed by S X = 0, S Y = 0, S Z = 1 corresponds to the space vector enclosed by S A = 1, S B = 1, S C = 0 corresponds to the space vector enclosed by S X = 1, S Y = 1, S Z = 0 corresponds to the space vector enclosed by S A = 0, S B = 1, S C = 1 corresponds to the space vector enclosed by S X = 0, S Y = 1, S Z = 1 corresponds to the space vector enclosed by S A = 1, S B = 0, S C = 1 corresponds to the space vector enclosed by S X = 1, S Y = 0, S Z = 1 corresponds to the space vector enclosed by S A = 0, S B = 1, S C = 0 corresponds to the space vector enclosed by S X = 1, S Y = 1, S Z = 0 corresponds to the space vector enclosed by S A = 0, S B = 1, S C = 1 corresponds to the space vector enclosed by S X = 0, S Y = 1, S Z = 1 corresponds to the space vector enclosed by S A = 1, S B = 0, S C = 0 corresponds to the space vector enclosed by S X = 1, S Y = 0, S Z = 1 corresponds to the space vector enclosed by S

[0064] The judgment mode at the fourth sampling time of the subspaces I, V, IX is:

[0065] When the reference voltage vector is located in the sector, the four sampling times are 0T s , 0.25T s , 0.5T s, 0.75T s ;

[0066] When the reference voltage is located in the upper boundary region of the sector, the four sampling times are 0T s , 0.25T s -T min , 0.5T s , 0.75T s +T min , T min is the minimum sampling time;

[0067] When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s ;

[0068] The judgment mode of the four sampling times in the subspace II, VI, X is:

[0069] When the reference voltage vector is located in the sector, the four sampling times are 0T s , 0.25T s , 0.5T s , 0.75T s ;

[0070] When the reference voltage is located in the upper boundary region of the sector, the four sampling times are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s , T min is the minimum sampling time;

[0071] When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T s , 0.25T s +T min , 0.5T s , 0.75T s -T min ;

[0072] The judgment mode of the four sampling times in the subspace III, VII, XI is:

[0073] When the reference voltage vector is located in the sector, the four sampling times are 0T s , 0.25T s , 0.5T s0.75T s ;

[0074] When the reference voltage is located in the upper boundary region of the sector, the four sampling times are 0T. s 0.25T s +T min 0.5T s 0.75T s -T min T min Minimum sampling time;

[0075] When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T. s -T min 0.25T s 0.5T s +T min 0.75T s ;

[0076] The method for determining the sampling time in sectors IV, VIII, and XII is as follows:

[0077] When the reference voltage vector is located within the sector, the four sampling times are 0T. s 0.25T s 0.5T s 0.75T s ;

[0078] When the reference voltage is located in the upper boundary region of the sector, the four sampling times are 0T. s -T min 0.25T s 0.5T s +T min 0.75T s .

[0079] When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T. s 0.25T s -T min 0.5T s 0.75T s +T min T min This is the minimum sampling time. This implementation effectively avoids the blind spot in sector boundary reconstruction by changing the sampling time;

[0080] In view of the problem that at least two current sensors are needed in the traditional DTP-PMSM control system, the current sampling topology is modified in the embodiment, and the sum of the currents of the upper tube of the B phase and the lower tube of the C phase in the first set of three-phase windings ABC and the upper tube of the X phase and the lower tube of the Y phase in the second set of three-phase windings XYZ is sampled by using a single current Hall sensor. The corresponding relationship between the current sensor sampling results and the phase currents under different voltage vectors is as follows:

[0081]

[0082] wherein i A i B i C i X i Y i Z are six-phase currents; I sum-ABC is the current sensor sampling result of the ABC three-phase under different voltage vectors; I sum-XYZ is the current sensor sampling result of the ABC three-phase under different voltage vectors.

[0083] The speed and position angle required for the operation of the motor are sampled.

[0084] According to the superposition principle, the current sensor sampling can be decomposed into the sum of the currents formed by the first set of three-phase windings ABC and the second set of three-phase windings XYZ under the action of corresponding voltage vectors.

[0085] I SAMPLE = I sum-UVW + I sum-XYZ (3)

[0086] wherein I sum-UVW is the current formed by winding 1 under the action of a corresponding voltage vector; I sum-XYZ is the current formed by winding 2 under the action of a corresponding voltage vector.

[0087] The six-phase current reconstruction expression of the double three-phase permanent magnet synchronous motor in each subspace is as follows:

[0088] Table 1 corresponding relationship between current sensor sampling results and phase currents under different voltage vectors

[0089]

[0090]

[0091]

[0092] wherein ABC-000 represents the S A , S B , S CThe time when the zero vector whose all elements are 0 acts;

[0093] ABC-111 represents the S A , S B , S C The time when the zero vector whose all elements are 1 acts;

[0094] XYZ-000 represents the S X , S Y , S Z The time when the zero vector whose all elements are 0 acts;

[0095] XYZ-111 represents the S X , S Y , S Z The time when the zero vector whose all elements are 1 acts;

[0096] I1, I2, I3, I4 respectively represent the currents sampled at four sampling times;

[0097] i A represents the current of phase A in the first set of three-phase windings ABC

[0098] i B represents the current of phase B in the first set of three-phase windings ABC

[0099] i C represents the current of phase C in the first set of three-phase windings ABC

[0100] i X represents the current of phase X in the second set of three-phase windings XYZ

[0101] i Y represents the current of phase Y in the second set of three-phase windings XYZ

[0102] i Z represents the current of phase Z in the second set of three-phase windings XYZ

[0103] Step 3, the difference between the given speed of the motor and the actual speed is sent to the speed controller ASR to obtain the torque given current of the motor. The reconstructed current is converted by the VSD coordinate to obtain the torque current feedback value i q , the flux linkage current feedback value i d , and the harmonic current feedback values i Z1 i Z2 , which are sent to the current loop controller ACR to obtain the torque voltage given value u q , the flux linkage voltage given value u d , and the harmonic voltage given values u z1u z2 。u z1 u z2 are two mutually orthogonal bases, which constitute the harmonic voltage space under the VSD coordinate system. The particularity of VSD control is to control the harmonic voltage.

[0104] Step 4, in order to solve the problem of two-step operation of the reference voltage vector under the VSD coordinate system to the two independent SVM modulation, the embodiment adopts VSD-2DQ equivalent transformation to obtain two sets of three-phase SVM given values from the VSD coordinate system voltage reference given value output by the current loop controller, and finally generates six-phase bridge arm drive signals through two sets of three-phase SVM strategies.

[0105]

[0106] Wherein, θ represents the electrical angle of the dual three-phase permanent magnet synchronous motor;

[0107] According to two sets of three-phase winding SVM given voltage values u d1 , u q1 , u d2 , u q2 , six-phase bridge arm drive signals of the dual three-phase permanent magnet synchronous motor are generated.

[0108] The embodiment simplifies the process of giving the current loop output to the pulse width modulation to single-step operation through VSD-2DQ equivalent transformation.

[0109] The embodiment adopts three-phase independent SVM strategy, simplifies the original high degree of freedom vector combination according to the 30° phase belt angle DTP-PMSM space vector characteristics, obtains a simplified sector, judges the position of the reference voltage vector based on the current sector of the two sets of three-phase windings, modifies the sampling topology to obtain the corresponding relationship of the sensor phase current, collects the speed and position angle required for motor operation and other control quantities, shifts the carrier of the second set of three-phase windings XYZ, constructs the sampling switch combination, flexibly configures the sampling time according to the sector position of the reference voltage, avoids the reconstruction blind area, samples at four zero vectors respectively, and obtains four sets of sampling currents with six-phase current information; complete six-phase current reconstruction based on current reconstruction expression under different sectors; send the reconstructed current to the VSD control loop to generate the given reference voltage output under the VSD coordinate system; through VSD-2DQ equivalent transformation, two sets of three-phase SVM given values are obtained through single-step calculation, and finally six-phase bridge arm drive signals are generated.

[0110] Embodiment:

[0111] The embodiment adopts a 16-pole, 125 rpm, 30° phase belt angle dual three-phase permanent magnet synchronous motor for simulation experiment, the switching frequency is 25 kHz, and the two sets of three-phase windings are independently star-connected. As shown inFigure 1 As shown, the main control loop adopts vector space decomposition (VSD) closed-loop control.

[0112] A two-set three-phase SVM strategy simplifies the voltage space vector. Based on the spatial distribution characteristics of the 30° phase band angle DTP-PMSM windings, winding 1 is equivalently rotated 30° to generate winding 2, thereby transforming the switching combination between the two sets of three-phase windings from an arbitrary combination to an adjacent effective combination. For example... Figure 3 As shown, the voltage vector U of the XYZ windings 21 For example, when rotated counterclockwise with the reference voltage, U 21 U of the ABC windings respectively 11 U 12 U 13 By combining them, U was excluded. 21 with U 14 U 15 U 16 The large-span switching combinations simplify the 64 types of switching vectors. Subspaces I to XII are generated, and the location of the reference voltage vector can be determined based on the current three-phase SVM subspace of winding 1 and winding 2.

[0113] For example, when both winding 1 and winding 2 are located in the first subspace of the six subspaces of the three-phase SVM, for the first set of windings, the reference voltage is between U and U. 11 with U 12 Between, for the second set of windings, the reference pressing is between U 21 with U 22 Between, such as Figure 3 As shown, U at this time ref It is located in subspace II;

[0114] according to Figure 2 It can be seen that the current collected by the current Hall effect sensor is the sum of the zero-sequence loop current of the lower tube of phase B and the upper tube of phase C of winding ABC 1, and the zero-sequence loop current of the lower tube of phase X and the upper tube of phase Y of winding XYZ 2. According to the superposition principle, the current sensor sampling can be decomposed into the sum of the currents formed by windings 1 and 2 under the action of corresponding voltage vectors. SAMPLE .

[0115] When winding 1 and winding 2 simultaneously apply zero vector 000, according to Figure 2 It can be seen that since the downward direction of the current sensor is defined as the positive direction, I... sum-UVW =-i B I sum-XYZ =-i X The sum of the two results gives the current sensor sampling result as I. SAMPLE =-iB -i X The DTP-PMSM voltage vector is split into two sets of three-phase SVM voltage vectors, and the voltage vectors of the two sets of three-phase SVMs form corresponding currents in the three-phase winding, and the superposition produces a current sensor sampling current. The rotation angle and speed of the motor are sampled.

[0116] Because the two sets of winding zero vectors overlap each other, the four zero vector sampling requirements in one switching cycle cannot be met. The second set of winding carrier is lagged by 1 / 4 switching cycle to construct four sets of zero vector corresponding switching combinations. After phase shifting, the current sampling result is shown in Figure 5

[0117] With the rotation of the reference voltage, three regions will be encountered in a sector, which are: the sector lower boundary effective vector reconstruction blind area, the sector, the sector upper boundary effective vector reconstruction blind area, and the sampling time needs to be selected flexibly to avoid the sampling blind area.

[0118] ①Take subspace I as an example, when the reference voltage vector is located in the sector:

[0119] The sampling time is shown in Fig. 4(a), and the effective vector action time satisfies:

[0120]

[0121] Where is the U 11 action time; is the U 12 action time; is the U 21 action time; is the U 26 action time;

[0122] The sampling time is selected as 0T s , 0.25T s , 0.5T s , 0.75T s , and I1, I3, I2, I4 can be sampled respectively, as shown in Table 1. The sampling current and phase current corresponding relationship is:

[0123]

[0124] According to the reconstruction equation provided in Table 1:

[0125]

[0126] The six-phase current can be reconstructed.

[0127] ②When the reference voltage vector is located in the sector upper boundary effective vector reconstruction blind area: ​

[0128] The sampling time is shown in Fig. 4(b), at which the effective vector acting time satisfies:

[0129]

[0130] The sampling time is changed to 0T s , 0.25T s -T min , 0.5T s , 0.75T s +T min , respectively, to obtain I1, I3, I2 and I4, respectively, and the current reconstruction is performed according to formula (7).

[0131] ③ When the reference voltage vector is located in the sector lower boundary effective vector reconstruction blind area:

[0132] At this time, the effective vector acting time satisfies:

[0133]

[0134] The sampling time is changed to 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s , respectively, to obtain I1, I3, I2 and I4, respectively, and the current reconstruction is performed according to formula (7).

[0135] The current reconstruction is completed according to Table 1, as shown in Fig. 7, the actual current and the reconstructed current have the same phase and basically consistent amplitude. As shown in Figure 8 the reconstruction error is controlled within the allowable range, meeting the reconstruction requirements.

[0136] The difference between the given speed of the motor and the actual speed is sent to the speed controller ASR to obtain the motor torque current given.

[0137] The six-phase current is sent to formula (10) to obtain the torque current feedback value, the flux current feedback value and the harmonic current feedback value in the VSD coordinate system.

[0138]

[0139] The difference between the feedback current and the given current is sent to the current loop controller ACR to obtain the torque reference voltage, the flux reference voltage and the harmonic reference voltage in the VSD coordinate system.

[0140] The reference voltage in the VSD coordinate system is converted into two groups of three-phase reference voltages by using the VSD-2DQ equivalent conversion formula (4) VSD-2DQ, and is sent into three-phase SVM, and finally six-phase bridge arm driving signals are generated through two groups of three-phase SVM strategies to complete the DTP-PMSM motor driving.

[0141] Since the reconstruction method of the application only involves the reconstruction topology, the modulation mode, the control variable and the reconstruction method, the embodiment does not have constraints on the controller. The embodiment is also applicable to application occasions where the speed loop controller adopts an active disturbance rejection controller, and the current loop controller adopts a proportional resonant controller.

[0142] While the application has been described with reference to particular embodiments thereof, it should be understood that these are merely illustrative of the principles and application of the application. It will thus be appreciated that numerous modifications can be made to the illustrative embodiments and that other arrangements can be devised without departing from the spirit and scope of the application as defined by the appended claims. It will be understood that, by combining different dependent claims with the features of the various embodiments, new claims can be formed, only some of which have been described herein. It will also be understood that features described with reference to one embodiment can be used in other embodiments.

Claims

1. A current reconstruction method for a 30° phase belt angle dual three-phase permanent magnet synchronous motor, characterized in that, The method comprises: S1, uniformly planning two sets of three-phase winding space vectors of a dual three-phase permanent magnet synchronous motor in the same phase space: wherein, U dc is the bus voltage; S A , S B , S C , S X , S Y , S Z are six-phase bridge arm switching functions, taking 0 value to represent that the lower tube of the bridge arm is turned on, and taking 1 value to represent that the upper tube of the bridge arm is turned on; U 1k is a space vector formed by a first set of three-phase windings ABC; U 2k is a space vector formed by a second set of three-phase windings XYZ, k = 1, 2, 3, 4, 5, 6. Integrate the two sets of three-phase winding space vectors into the same phase space plane to obtain 12 subspaces in the phase space plane; S2, the carrier of the second set of three-phase winding XYZ lags behind the first set of three-phase winding ABC by 1 / 4 switching period T s The four zero voltage vector corresponding switch combinations are constructed, and the two sets of three-phase windings are sampled four times under different zero vectors in a switching period, so as to obtain the six-phase current reconstruction expression of the double three-phase permanent magnet synchronous motor in each subspace. According to the position of the reference voltage vector in the phase space, the corresponding six-phase current reconstruction expression is selected to reconstruct the six-phase current of the double three-phase permanent magnet synchronous motor.

2. The current reconstruction method of a 30° phase belt angle double three-phase permanent magnet synchronous motor according to claim 1, characterized in that, Each subspace is surrounded by two space vectors, and each subspace includes upper and lower boundary regions and sectors therebetween; the determination method of the upper and lower boundary regions is that the time maintained by the corresponding space vectors of the two sets of three-phase windings when sampling in the sector at the sampling time cannot meet the minimum sampling time; Subspace I is enclosed by the space vectors corresponding to S A = 1, S B = 0, S C = 0, S X = 1, S Y = 0, S Z = 0, S A = 0, S B = 1, S C = 0, S X = 0, S Y = 1, S Z = 0, S A = 0, S B = 0, S C = 1, S X = 0, S Y = 0, S Z = 1. The judgment mode of the four sampling time points of the subspaces I, V and IX is: When the reference voltage vector is located in a sector, the four sampling instants are 0T s , 0.25T s , 0.5T s , 0.75T s , respectively. When the reference voltage is in the upper boundary region of the sector, the four sampling instants are 0T s , 0.25T s -T min , 0.5T s , 0.75T s +T min , T min being the minimum sampling time; When the reference voltage is at the lower boundary region of the sector, the four sampling instants are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s ; Subspace II is enclosed by the space vectors corresponding to S A = 1, S B = 1, S C = 0, S X = 1, S Y = 0, S Z = 0, S A = 0, S B = 1, S C = 1, S X = 0, S Y = 1, S Z = 0, S A = 1, S B = 0, S C = 1, S X = 0, S Y = 0, S Z = 1, S The judgment mode of the four sampling time points of the subspaces II, VI and X is: When the reference voltage vector is located within a sector, the four sampling instants are 0T s , 0.25T s , 0.5T s , 0.75T s , respectively. When the reference voltage is in the upper boundary region of the sector, the four sampling instants are 0T s +T min , 0.25T s , 0.5T s -T min , 0.75T s , T min , the minimum sampling time; When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T. s 0.25T s +T min 0.5T s 0.75T s -T min ; Subspace III is enclosed by the space vectors corresponding to S A = 1, S B = 1, S C = 0, S X = 1, S Y = 1, S Z = 0, S A = 0, S B = 1, S C = 1, S X = 0, S Y = 1, S Z = 1, S A = 1, S B = 0, S C = 1, S X = 1, S Y = 0, S Z = 1, S The judgment mode of the four sampling time points of the subspaces III, VII and XI is: When the reference voltage vector is located within a sector, the four sampling instants are 0T s , 0.25T s , 0.5T s , 0.75T s , respectively. When the reference voltage is in the upper boundary region of the sector, the four sampling instants are 0T s , 0.25T s +T min , 0.5T s , 0.75T s -T min , T min is the minimum sampling time; When the reference voltage is in the lower boundary region of the sector, the four sampling instants are 0T s -T min , 0.25T s , 0.5T s +T min , 0.75T s ; Subspace IV is enclosed by the space vectors corresponding to S A = 0, S B = 1, S C = 0, and S X = 1, S Y = 1, S Z = 0; Subspace VIII is enclosed by the space vectors corresponding to S A = 0, S B = 1, S C = 1, and S X = 0, S Y = 1, S Z = 1; Subspace XII is enclosed by the space vectors corresponding to S A = 1, S B = 0, S C = 0, and S X = 1, S Y = 0, S Z = 1. The judgment mode of the four sampling time points of the subspaces IV, VIII and XII is: When the reference voltage vector is located within a sector, the four sampling instants are 0T s , 0.25T s , 0.5T s , 0.75T s , respectively. When the reference voltage is in the upper boundary region of the sector, the four sampling instants are 0T s -T min , 0.25T s , 0.5T s +T min , 0.75T s； When the reference voltage is located in the lower boundary region of the sector, the four sampling times are 0T. s 0.25T s -T min 0.5T s 0.75T s +T min T min This is the minimum sampling time.

3. The current reconstruction method of a 30° phase belt angle double three-phase permanent magnet synchronous motor according to claim 2, characterized in that, The sum of the currents of the B-phase upper tube and the C-phase lower tube in the first set of three-phase windings ABC and the X-phase upper tube and the Y-phase lower tube in the second set of three-phase windings XYZ is sampled by using a single current Hall sensor.

4. The current reconstruction method of a 30° phase belt angle double three-phase permanent magnet synchronous motor according to claim 3, characterized in that, The six-phase current reconstruction expression of the dual three-phase permanent magnet synchronous motor in each subspace is reconstructed as: wherein ABC-000 represents the time when the zero vector of S A , S B , S C all being 0 acts; ABC-111 represents S of the first set of three-phase winding ABC in the switching period A , S B , S C the time when the zero vector whose elements are all 1 acts XYZ-000 indicates the S of the second set of three-phase winding XYZ within the switching period X , S Y , S Z is the time when the zero vector acting on all of 0 XYZ-111 represents the S of the second set of three-phase winding XYZ in the switching period X , S Y , S Z the time when the zero vector whose all elements are 1 acts I1, I2, I3 and I4 represent the currents sampled at the four sampling time points, respectively; i A denotes the current of phase A in the first set of three-phase windings ABC i B denotes the current of phase B in the first set of three-phase windings ABC; i C Ic represents the current of phase C in the first set of three-phase windings ABC; i X Ix represents the current in the X phase of the second set of three-phase windings XYZ; i Y Iy represents the current in the Y phase of the second set of three-phase windings XYZ i Z denotes the current in the Z phase of the second set of three-phase windings XYZ.

5. The current reconstruction method of a 30° phase belt angle double three-phase permanent magnet synchronous motor according to claim 2, characterized in that, The method further comprises: S3, the reconstructed current is transformed by VSD to get torque current feedback value i q , flux linkage current feedback value i d , harmonic current feedback value i orthogonal to each other Z1 , i Z2 , respectively, and the corresponding given current is subtracted to send into the current loop controller to get torque voltage given value u q , flux linkage voltage given value u d , harmonic voltage given value u orthogonal to each other z1 u z2 ; According to the torque voltage given value u q , flux linkage voltage given value u d , harmonic voltage given value u z1 , u z2 Two sets of three-phase winding SVM given voltage value u is obtained by using VSD-2DQ equivalent transformation matrix d1 , u q1 , u d2 , u q2 : Wherein, θ represents the electrical angle of the dual three-phase permanent magnet synchronous motor; According to two sets of three-phase winding SVM given voltage value u d1 、 u q1 、 u d2 、 u q2 , generate six-phase bridge arm drive signal of double three-phase permanent magnet synchronous motor.

6. The current reconstruction method of a 30° phase belt angle double three-phase permanent magnet synchronous motor according to claim 5, characterized in that, The reconstructed current is transformed by VSD to obtain torque current feedback value i q , flux linkage current feedback value i d , harmonic current feedback value i Z1 , i Z2 : where i A , i B , i C , i X , i Y , i Z represents the reconstructed six-phase current of the dual three-phase permanent magnet synchronous motor.

7. A computer-readable storage device storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1-6. The computer program is executed by the processor to realize the steps of the current reconstruction method of the 30° phase belt angle dual three-phase permanent magnet synchronous motor according to any one of claims 1 to 6.

8. A magnetic disc satellite moment attitude control apparatus comprising a storage device, a processor, and a computer program stored in the storage device and operable on the processor, characterized in that, The processor executes the computer program to realize the steps of the current reconstruction method of the 30° phase belt angle dual three-phase permanent magnet synchronous motor according to any one of claims 1 to 6.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the current reconstruction method of the 30° phase belt angle dual three-phase permanent magnet synchronous motor according to any one of claims 1 to 6.

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