Position sensorless control method of dual three-phase permanent magnet synchronous motor considering open-phase fault

Abstract

The invention discloses a dual three-phase permanent magnet synchronous motor sensorless control method considering an open-phase fault. The method comprises the following steps: injecting high-frequency square wave voltage into a beta axis of the dual three-phase permanent magnet synchronous motor under an alpha-beta two-phase static coordinate system, extracting d-axis high-frequency response current under a d-q synchronous rotation coordinate system, and reconstructing a pair of sine envelope signals according to the d-axis high-frequency response current; setting a rotor position angle error according to the operation condition of the dual three-phase permanent magnet synchronous motor; the rotor estimated position is updated using a phase-locked loop in combination with the rotor estimated position, the rotor position angle error, and the pair of reconstructed envelope signals. According to the method, position-sensorless control of the dual three-phase permanent magnet synchronous motor during open-phase fault operation of any one phase or two phases is realized.

Description

Technical Field

[0001] The invention belongs to the field of position sensorless control of multi-phase permanent magnet synchronous motors, and in particular relates to a position sensorless control method of a dual three-phase permanent magnet synchronous motor under a phase failure. Background Art

[0002] As one of the key technologies in the industrial field, the green and intelligent upgrade of AC drive system is of great significance to the realization of carbon peak and carbon neutrality goals. Multiphase motors are gradually increasing in applications such as aerospace, ship propulsion, and new energy vehicles due to their high power density, good fault tolerance, and high degree of freedom. Among them, the two sets of windings of the dual three-phase permanent magnet synchronous motor are phase-shifted by 30°. This structural feature eliminates the six torque pulsations of the motor and makes the torque more stable during operation. When the motor system is running, accurate rotor position information is crucial to the control performance of the motor. Usually, the rotor position information is obtained by a mechanical position sensor, but the installation of a mechanical sensor will increase the cost and volume of the motor system. To solve this problem, position sensorless control technology is particularly important. Compared with traditional three-phase motors, high fault tolerance when the motor has a phase failure is a significant advantage of multiphase motors. Therefore, position sensorless control of dual three-phase permanent magnet synchronous motors when there is a phase failure is crucial.

[0003] At present, most existing methods introduce low-pass filters to suppress the DC component in the high-frequency current caused by the high-frequency signal injection into the stationary coordinate system to estimate the rotor position, which affects the system bandwidth. In addition, for the position sensorless control of the dual three-phase permanent magnet synchronous motor when the motor is running with a phase loss fault, the existing methods do not analyze the inductance change after the phase loss. However, there is a lot of rotor position information in the inductance matrix, especially when the motor is running with a phase loss, the inductance matrix is ​​no longer symmetrical, so the inductance change after the phase loss has special research value for the high-frequency injection position sensorless control method. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a position sensorless control method for a dual three-phase permanent magnet synchronous motor taking into account a phase failure. The method of the present invention injects a high-frequency square wave voltage into a single axis of a stationary coordinate system, and then extracts position information in a synchronous rotating coordinate system, thereby avoiding the problem of a DC component in a high-frequency current, and proposes a position compensation method based on a second-order generalized integrator-phase-locked loop according to the inductance change when any one or two phases of the dual three-phase permanent magnet synchronous motor are missing, thereby realizing position sensorless control when any one or two phases of the dual three-phase permanent magnet synchronous motor are missing.

[0005] The technical solution adopted by the present invention is as follows:

[0006] 1. A sensorless control method for dual three-phase permanent magnet synchronous motor considering phase failure

[0007] The control method comprises the following steps:

[0008] S1. Inject a high-frequency square wave voltage into the β-axis of the dual three-phase permanent magnet synchronous motor in the α-β two-phase stationary coordinate system, collect the six-phase current of the dual three-phase permanent magnet synchronous motor, extract the d-axis high-frequency response current in the dq synchronous rotating coordinate system by performing coordinate transformation on the six-phase current, input the envelope of the d-axis high-frequency response current into a second-order generalized integrator, reconstruct a pair of sinusoidal envelope signals with equal amplitude and a phase difference of 90°, and input the reconstructed envelope signal into a phase-locked loop.

[0009] S2. Set the rotor position angle error according to the operating conditions of the dual three-phase permanent magnet synchronous motor.

[0010] The step S2 is specifically as follows:

[0011] When the dual three-phase permanent magnet synchronous motor operates normally, the rotor position angle error is set to zero;

[0012] When a phase loss fault occurs in the dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error during the phase loss fault according to the type of the phase loss fault; the types of the phase loss fault include single-phase phase loss fault, two-phase phase loss fault with a phase difference of 30°, two-phase phase loss fault with a phase difference of 150°, two-phase phase loss fault with a phase difference of 270° and two-phase phase loss fault with a phase difference of 120°.

[0013] a. When a single-phase failure occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error Set to the rotor position angle error when a single-phase failure occurs Rotor position angle error during single-phase failure It is obtained by the following formula:

[0014]

[0015] In the formula, Indicates the rotor position angle error when a single-phase failure occurs. represents the estimated position error angle caused by a single-phase failure, Indicates the angle between the fault phase and phase A. The fault phase is phase A, phase B, phase C, phase U, phase V or phase W.

[0016] The estimated position error angle caused by a single-phase failure is set according to the following formula:

[0017]

[0018] In the formula, represents the estimated position error angle caused by a single-phase failure, It represents the angle between the fault phase and phase A, K represents the high-frequency current coefficient when phase A is out of phase, K' represents the high-frequency current coefficient when single-phase is out of phase, L1 represents the first single-phase out of phase coefficient, and L3 represents the second single-phase out of phase coefficient.

[0019] Among them, the high-frequency current coefficient K, the first single-phase phase loss coefficient L1, and the second single-phase phase loss coefficient L3 during the phase A phase loss fault are calculated by the following formulas using known parameters:

[0020]

[0021] Where, L1 represents the first single-phase loss coefficient, L3 represents the second single-phase loss coefficient, K represents the high-frequency current coefficient when the A phase is lost, L0 represents the mean inductance, L2 represents the differential inductance, L z represents the motor leakage inductance of the dual three-phase permanent magnet synchronous motor, and θ represents the electrical angle form of the rotor position.

[0022] Among them, the mean inductance L0 and the difference inductance L2 are obtained according to the d-axis inductance and the q-axis inductance in the dq synchronous rotating coordinate system respectively by the following formulas:

[0023] L0=(L d +L q ) / 2

[0024] L2=(L d -L q ) / 2

[0025] Where L0 represents the mean inductance, L2 represents the differential inductance, and L d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q It represents the q-axis inductance in the dq synchronous rotating coordinate system.

[0026] b. When a dual three-phase permanent magnet synchronous motor has a two-phase failure with a phase difference of 30°, the rotor position angle error Set to the rotor position angle error when the two phases are out of phase with a difference of 30° The rotor position angle error when the two phases are missing due to a 30° phase difference It is obtained by the following formula:

[0027]

[0028] In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 30°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°. It represents the estimated position error angle caused by a two-phase failure with a phase difference of 30°.

[0029] Among them, the estimated position error angle caused by the two-phase failure with a phase difference of 30° is Set it according to the following formula:

[0030]

[0031] In the formula, It represents the estimated position error angle caused by the two-phase failure with a phase difference of 30°, K d-30 Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q-30 It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. It indicates the angle between the faulty phase of the first set of windings in the two faulty phases and phase A.

[0032] Among them, the inherent phase loss estimation position error angle when the two phases are 30° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q-30 , d-axis high-frequency current coefficient K when phase A and phase U are missing d-30 Set them according to the following formulas:

[0033]

[0034] In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase loss fault.

[0035] The first set of windings includes phase A, phase B and phase C. These three-phase windings are spaced 120 degrees apart in electrical angle and together constitute a three-phase subsystem in the six-phase motor.

[0036] c. When a dual three-phase permanent magnet synchronous motor has a two-phase failure with a phase difference of 150°, the rotor position angle error Set to the rotor position angle error when the phase difference is 150° and the two phases are missing The rotor position angle error when the two phases are missing due to a phase difference of 150° It is obtained by the following formula:

[0037]

[0038] In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 150°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°. It represents the estimated position error angle caused by a two-phase failure with a phase difference of 150°.

[0039] Among them, the estimated position error angle caused by the two-phase failure with a phase difference of 150° is Set it according to the following formula:

[0040]

[0041] In the formula, It represents the estimated position error angle caused by the two-phase failure with a phase difference of 150°, K d-150 Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q-150 It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. It indicates the angle between the faulty phase of the first set of windings in the two faulty phases and phase A.

[0042] Among them, the inherent phase loss estimation position error angle when the two phases are 150° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q-150 , d-axis high-frequency current coefficient K when phase A and phase U are missing d-150 Set them according to the following formulas:

[0043]

[0044] In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase loss fault.

[0045] Among them, the first two-phase loss phase coefficient L4, the second two-phase loss phase coefficient L5, the third two-phase loss phase coefficient L6, the fourth two-phase loss phase coefficient L7, and the high-frequency current coefficient K2 during two-phase loss phase fault are calculated by the known parameters according to the following formulas:

[0046]

[0047] Where, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, L0 represents the mean inductance, L2 represents the difference inductance, Lz represents the leakage inductance of the motor, θ represents the electrical angle form of the rotor position, and K2 represents the high-frequency current coefficient when two-phase failure occurs.

[0048] d. When a dual three-phase permanent magnet synchronous motor has a two-phase failure with a phase difference of 270°, the rotor position angle error The rotor position angle error is set to zero when there is a two-phase loss fault with a difference of 270°.

[0049] e. When a dual three-phase permanent magnet synchronous motor has a two-phase failure with a phase difference of 120°, the rotor position angle error The rotor position angle error is set to zero when there is a two-phase loss fault with a difference of 120°.

[0050] S3, using a phase-locked loop combined with the current rotor estimated position and rotor position angle error and a pair of reconstructed envelope signals to update the estimated rotor position.

[0051] The step S3 comprises the following steps:

[0052] S3.1, using a phase-locked loop to estimate the rotor position ( and rotor position angle error sum As the angle of the sine signal sin and the cosine signal cos, the sine signal and the cosine signal are respectively compared with the cosine envelope I in the sine envelope signal. cos , Sine envelope I sin Multiply them and make a difference between the two product values ​​(i.e., use the sine envelope I sin The product value is subtracted from the cosine envelope I cos The obtained product value) is used to obtain the position error Δθ;

[0053] S3.2, using the PI regulator to perform proportional and integral processing on the position error to obtain an estimated speed;

[0054] S3.3. Use an integrator to integrate the estimated rotational speed to obtain a new estimated rotor position, and use the new estimated rotor position to update the estimated rotor position.

[0055] The phase-locked loop inputs the estimated rotation speed obtained in step S3.2 into a second-order generalized integrator, and the second-order generalized integrator uses the estimated rotation speed as the resonant frequency.

[0056] S4. Use a phase-locked loop to input the updated estimated rotor position into the input end of the phase-locked loop. The phase-locked loop uses the updated estimated rotor position as the current estimated rotor position at the next moment, and then dynamically updates the estimated rotor position according to step S3. At the same time, use the phase-locked loop to close the updated estimated rotor position into the motor controller, replacing the role of the traditional position sensor and realizing position sensorless control.

[0057] The beneficial effects brought about by the technical solution of the present invention are:

[0058] The present invention proposes a position sensorless control method under a dual three-phase permanent magnet synchronous motor phase loss fault, which compensates for the position error caused by the dual three-phase permanent magnet synchronous motor phase loss fault and realizes high-precision position sensorless control under phase loss fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the windings of the dual three-phase permanent magnet synchronous motor in the present invention;

[0060] Figure 2 It is a schematic diagram of an equivalent two-phase static coordinate system in the event of a phase failure in the present invention;

[0061] Figure 3 is a block diagram of a second-order generalized integrator in the present invention;

[0062] Figure 4 It is a structural block diagram of a phase-locked loop with angle compensation in the present invention;

[0063] Figure 5 It is a frequency adaptive second-order generalized integrator-phase-locked loop block diagram of the present invention;

[0064] Figure 6 It is a speed change simulation result diagram of the present invention;

[0065] Figure 7 This is a simulation result diagram when any one phase is missing in the present invention;

[0066] Figure 8 This is a simulation result diagram of any two-phase loss fault in the present invention. DETAILED DESCRIPTION

[0067] The following is a detailed description of a position sensorless control method for a dual three-phase permanent magnet synchronous motor under a phase failure of the present invention in conjunction with the embodiments and drawings.

[0068] The present invention proposes a position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure: first, a high-frequency square wave voltage is injected into a single axis in a stationary coordinate system, and then the rotor position information is extracted from the high-frequency current in a synchronous rotating coordinate system, thereby avoiding the problem of a DC component in the high-frequency current. Secondly, the inductance change when any one or two phases of the dual three-phase permanent magnet synchronous motor are missing is analyzed, and then a position compensation method based on a second-order generalized integrator-phase-locked loop is proposed, which realizes high-precision position sensorless control when any one or two phases of the dual three-phase permanent magnet synchronous motor are missing.

[0069] The specific embodiments of the present invention are as follows:

[0070] Example 1

[0071] This embodiment analyzes the inductance change when any one or two phases of the dual three-phase permanent magnet synchronous motor are in phase failure, and then predicts the rotor position angle error when different phase failures occur. The specific process is as follows:

[0072] 1) First, the dual three-phase permanent magnet synchronous motor is modeled using the vector space decoupling mathematical model, the two sets of three-phase windings of the dual three-phase permanent magnet synchronous motor are transformed in coordinates respectively, and the voltage equation and magnetic flux equation in the dq synchronous rotating coordinate system are set according to the following formulas.

[0073] Figure 1 Schematic diagram of the windings of the dual three-phase permanent magnet synchronous motor in the present invention, Figure 1 In the figure, A, B, C, U, V, and W represent six-phase windings, and N represents the neutral point.

[0074] The voltage equation in the dq synchronous rotating coordinate system is set according to the following formula:

[0075]

[0076] In the formula, u d 、u q They represent the d-axis voltage and q-axis voltage in the dq synchronous rotating coordinate system, respectively. d 、i q They represent the d-axis current and q-axis current in the dq synchronous rotating coordinate system, respectively. d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q represents the q-axis inductance in the dq synchronous rotating coordinate system, R represents the stator resistance of the dual three-phase permanent magnet synchronous motor, ω represents the angular frequency of the dual three-phase permanent magnet synchronous motor, Represents the flux amplitude of the dual three-phase permanent magnet synchronous motor.

[0077] Set the flux equation in the dq synchronous rotating coordinate system according to the following formula:

[0078]

[0079] In the formula, ψ dqs represents the magnetic flux in the dq synchronous rotating coordinate system, T represents the transformation matrix, T = T 6r T 6s , T 6r represents the rotation coordinate transformation matrix, L 6s represents the six-phase inductance matrix, I 6s represents the sixth-order unit matrix, λ represents the flux coefficient matrix, L z represents the motor leakage inductance of the dual three-phase permanent magnet synchronous motor, i d 、i q They represent the d-axis current and q-axis current in the dq synchronous rotating coordinate system, respectively. d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q represents the q-axis inductance in the dq synchronous rotating coordinate system, represents the flux amplitude of the dual three-phase permanent magnet synchronous motor, i x 、i y They represent the x-axis current and y-axis current of the harmonic plane respectively.

[0080] A high-frequency square wave voltage is injected into the β-axis of the dual three-phase permanent magnet synchronous motor model in the α-β two-phase stationary coordinate system. The high-frequency square wave voltage is set according to the following equation:

[0081]

[0082] In the formula, u αh represents the high frequency voltage of the α axis, u βh Represents the high-frequency voltage of the β axis, V inj Indicates the amplitude of high-frequency square wave voltage.

[0083] The frequency of the high-frequency square wave voltage is half of the switching frequency. In this embodiment, the switching frequency is 10 kHz and the high-frequency frequency is 5 kHz.

[0084] In the α-β two-phase stationary coordinate system, the high-frequency square wave voltage and the high-frequency response current satisfy the following relationship:

[0085]

[0086] Where L0 represents the mean inductance, L2 represents the differential inductance, θ represents the electrical angle form of the rotor position, and i αh represents the high-frequency response current of the α-axis in the α-β two-phase stationary coordinate system, i βh represents the high-frequency response current of the β axis in the α-β two-phase stationary coordinate system, u αhrepresents the high-frequency voltage on the α-axis in the α-β two-phase stationary coordinate system, u βh It represents the β-axis high-frequency voltage in the α-β two-phase stationary coordinate system.

[0087] Among them, the mean inductance L0 and the difference inductance L2 are obtained according to the d-axis inductance and the q-axis inductance in the dq synchronous rotating coordinate system respectively by the following formulas:

[0088] L0=(L d +L q ) / 2

[0089] L2=(L d -L q ) / 2

[0090] Where L0 represents the mean inductance, L2 represents the differential inductance, and L d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q It represents the q-axis inductance in the dq synchronous rotating coordinate system.

[0091] In the dq synchronous rotating coordinate system, the high-frequency square wave voltage and the high-frequency response current satisfy the following relationship:

[0092]

[0093] Where, L d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q represents the q-axis inductance in the dq synchronous rotating coordinate system, u dh represents the d-axis high-frequency voltage in the dq synchronous rotating coordinate system, u qh represents the q-axis high-frequency voltage in the dq synchronous rotating coordinate system, i dh represents the d-axis high-frequency response current in the dq synchronous rotating coordinate system, i qh It represents the q-axis high-frequency response current in the dq synchronous rotating coordinate system.

[0094] Map the high-frequency square wave voltage to the dq synchronous rotating coordinate system to obtain the high-frequency square wave voltage in the dq synchronous rotating coordinate system:

[0095]

[0096] In the formula, u αh represents the high-frequency voltage on the α-axis in the α-β two-phase stationary coordinate system, u βh It represents the β-axis high-frequency voltage in the α-β two-phase stationary coordinate system, and θ represents the electrical angle form of the rotor position.

[0097] Input the high-frequency square wave voltage in the dq synchronous rotating coordinate system into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system, and obtain the differential form of the high-frequency response current in the dq synchronous rotating coordinate system:

[0098]

[0099] In the formula, i d represents the d-axis high-frequency response current in the dq synchronous rotating coordinate system, i q represents the q-axis high-frequency response current in the dq synchronous rotating coordinate system, L d represents the d-axis inductance in the dq synchronous rotating coordinate system, L q It represents the q-axis inductance in the dq synchronous rotating coordinate system.

[0100] When the dual three-phase permanent magnet synchronous motor operates normally, the differential form of the high-frequency response current in the dq synchronous rotating coordinate system is discretized to obtain the differential form of the d-axis high-frequency current Δi d , through the differential form of the d-axis high-frequency current Δi d The symbolic processing is performed to obtain the envelope of the d-axis high-frequency current. The envelope of the d-axis high-frequency current is used as the input signal of the second-order generalized integrator. By reconstructing the envelope, a pair of orthogonal, equal-amplitude sinusoidal envelope signals containing position information can be obtained. This pair of sinusoidal envelope signals is input into the phase-locked loop, and the phase-locked loop is used to combine the current rotor estimated position and a pair of reconstructed envelope signals to update the rotor estimated position. The updated rotor estimated position is used as the current rotor estimated position at the next moment. At the same time, the updated rotor estimated position is closed-looped into the motor controller to replace the role of the traditional position sensor, realizing high-precision position sensorless control.

[0101] 2) First, the inductance matrix of the dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system is established when the A phase fails, and the established inductance matrix is ​​input into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system to obtain the high-frequency response current when the A phase fails. Based on the high-frequency response current when the A phase fails, the high-frequency response current when the single-phase fails is obtained. The rotor position angle error when the single-phase fails is obtained by integrating the high-frequency response current when the single-phase fails.

[0102] The specific steps include:

[0103] 2.1) Establish the inductance matrix of the dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system when the A phase failure occurs, specifically:

[0104]

[0105] Where, L dq-fA represents the inductance matrix of the dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system, L0 represents the mean inductance, L2 represents the difference inductance, L z represents the motor leakage inductance of the dual three-phase permanent magnet synchronous motor, and θ represents the electrical angle form of the rotor position.

[0106] 2.2) The inductance matrix in the dq synchronous rotating coordinate system when the phase A is out of phase is input into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system. Combined with the high-frequency square wave voltage in the dq synchronous rotating coordinate system, the discretized form of the high-frequency response current when the phase A is out of phase is obtained:

[0107]

[0108] In the formula, Δi d-fA Indicates the d-axis high-frequency response current when phase A is missing, Δi q-fA represents the q-axis high-frequency response current when phase A is missing, Δt represents the sampling time interval of the six-phase current, V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, K represents the high-frequency current coefficient when the A phase is out of phase, L1 represents the first single-phase out of phase coefficient, and L3 represents the second single-phase out of phase coefficient.

[0109] Among them, the high-frequency current coefficient K, the first single-phase phase loss coefficient L1, and the second single-phase phase loss coefficient L3 during the phase A phase loss fault are calculated by the following formulas using known parameters:

[0110]

[0111] Where, L1 represents the first single-phase loss coefficient, L3 represents the second single-phase loss coefficient, K represents the high-frequency current coefficient when the A phase is lost, L0 represents the mean inductance, L2 represents the differential inductance, L z represents the motor leakage inductance of the dual three-phase permanent magnet synchronous motor, and θ represents the electrical angle form of the rotor position.

[0112] 2.3) Establish an equivalent two-phase stationary coordinate system under a single-phase loss fault. Figure 2 is a schematic diagram of an equivalent two-phase stationary coordinate system in the event of a phase failure in the present invention, Figure 2 Where X1 represents the fault phase, and α'-β' represents the equivalent two-phase stationary coordinate system.

[0113] The offset angle between the equivalent two-phase stationary coordinate system and the α-β two-phase stationary coordinate system is at the same time, Indicates the angle between the fault phase and phase A. The fault phase is phase A, phase B, phase C, phase U, phase V or phase W. The high-frequency current when any phase is missing in the equivalent two-phase stationary coordinate system is obtained:

[0114]

[0115] In the formula, Δi' d-fX1 It represents the d-axis high-frequency response current in the equivalent two-phase stationary coordinate system, Δi' q-fX1 represents the q-axis high-frequency response current in the equivalent two-phase stationary coordinate system, represents the angle between the fault phase and phase A, L1 represents the first single-phase loss coefficient, L3 represents the second single-phase loss coefficient, Δt represents the current sampling time interval, V inj Indicates the amplitude of high-frequency square wave voltage.

[0116] According to the high-frequency current when any phase is out of phase in the equivalent two-phase stationary coordinate system, the high-frequency response current when a single-phase out of phase fault occurs in the α-β two-phase stationary coordinate system is obtained:

[0117]

[0118]

[0119] In the formula, Δi d-fX1 represents the d-axis high-frequency response current when a single-phase failure occurs, Δt represents the current sampling time interval, V inj Represents the amplitude of the high-frequency square wave voltage, represents the estimated position error angle caused by a single-phase failure, It represents the angle between the fault phase and phase A, K represents the high-frequency current coefficient when phase A is out of phase, K' represents the high-frequency current coefficient when single-phase is out of phase, L1 represents the first single-phase out of phase coefficient, and L3 represents the second single-phase out of phase coefficient.

[0120] 2.4) According to the high-frequency current during single-phase failure in the α-β two-phase stationary coordinate system, the position error of the single-phase failure is integrated into the position compensation angle The rotor position angle error during a single-phase failure is obtained by the following formula:

[0121]

[0122] In the formula, Indicates the rotor position angle error when a single-phase failure occurs. represents the estimated position error angle caused by a single-phase failure, Indicates the angle between the fault phase and phase A. The fault phase is phase A, phase B, phase C, phase U, phase V or phase W.

[0123] 3) Establish the inductance matrix of the dual three-phase permanent magnet synchronous motor when the A-phase and U-phase are missing, the A-phase and V-phase are missing, and the A-phase and W-phase are missing, and input the high-frequency voltage equation respectively to obtain the high-frequency response current during different phase missing faults. Based on the high-frequency response current during the A-phase and U-phase missing faults, obtain the high-frequency response current during the two-phase missing fault with any phase difference of 30°. Based on the high-frequency response current during the A-phase and V-phase missing faults, obtain the high-frequency response current during the two-phase missing fault with any phase difference of 150°. Based on the high-frequency response current during the A-phase and W-phase missing faults, obtain the high-frequency response current during the two-phase missing fault with any phase difference of 270°. Establish the high-frequency response current during the phase missing fault with any phase difference of 120°. According to the high-frequency response currents during the two-phase missing faults with any phase differences of 30°, 150°, 270°, and 120°, the rotor position angle error during the two-phase missing faults with any phase differences of 30°, 150°, 270°, and 120° is obtained by integrating the high-frequency response currents during the two-phase missing faults with any phase differences of 30°, 150°, 270°, and 120°.

[0124] 3.1) The rotor position angle error when there is a two-phase failure with an arbitrary phase difference of 30° is obtained by the following steps:

[0125] The inductance matrix of the dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system is established when the A-phase and U-phase are in phase failure, and it is input into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system. Combined with the high-frequency square wave voltage in the dq synchronous rotating coordinate system, the differential form of the high-frequency response current in the case of A-phase and U-phase phase failure is obtained:

[0126]

[0127] In the formula, Δi d-fAU Indicates the d-axis high-frequency response current when phase A and phase U are missing, Δi q-fAU represents the q-axis high-frequency response current when phase A and phase U are out of phase, Δt represents the current sampling time interval, V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, K2 represents the high-frequency current coefficient during a two-phase fault, L4 represents the first two-phase loss phase coefficient, L5 represents the second two-phase loss phase coefficient, L6 represents the third two-phase loss phase coefficient, and L7 represents the fourth two-phase loss phase coefficient.

[0128] Among them, the first two-phase loss phase coefficient L4, the second two-phase loss phase coefficient L5, the third two-phase loss phase coefficient L6, the fourth two-phase loss phase coefficient L7, and the high-frequency current coefficient K2 during two-phase fault are calculated by the known parameters according to the following formulas:

[0129]

[0130] Where, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, L0 represents the mean inductance, L2 represents the difference inductance, L z represents the leakage inductance of the motor, θ represents the electrical angle form of the rotor position, and K2 represents the high-frequency current coefficient when two-phase failure occurs.

[0131] According to the trigonometric function relationship, the high-frequency response current when the phase A and phase U are out of phase fault is simplified to obtain the simplified high-frequency response current when the phase A and phase U are out of phase fault:

[0132]

[0133] In the formula, Δi d-fAU Indicates the d-axis high-frequency response current when phase A and phase U are missing, Δi q-fAU represents the q-axis high-frequency response current when phase A and phase U are out of phase, Δt represents the current sampling time interval, V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, K d Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°.

[0134] Among them, the inherent phase loss estimation position error angle when the two phases are 30° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q , d-axis high-frequency current coefficient K when phase A and phase U are missing d Set them according to the following formulas:

[0135]

[0136] In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, and L7 represents the fourth two-phase loss coefficient.

[0137] By the same method as step 2.3), the d-axis high-frequency response current of any two-phase failure with a phase difference of 30° is obtained based on the simplified high-frequency response current of the A-phase and U-phase failure:

[0138]

[0139] In the formula, Δi d-f2X30It represents the high-frequency response current when there is a two-phase failure with a phase difference of 30°. Δt represents the current sampling time interval. V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimation position error angle when there is a two-phase loss fault with a phase difference of 30°. This angle is independent of the spatial distribution of the fault phase. It represents the estimated position error angle caused by a two-phase failure with a phase difference of 30°.

[0140] According to the high-frequency response current of any two-phase failure with a phase difference of 30° in the α-β two-phase stationary coordinate system, the position error of any two-phase failure with a phase difference of 30° is integrated into the position compensation angle The rotor position angle error when there is a two-phase failure with a phase difference of 30° is obtained by the following formula:

[0141]

[0142] In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 30°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°. It represents the estimated position error angle caused by the two-phase failure with a phase difference of 30°, K 30 is the d-axis high-frequency current coefficient for any 30° two-phase failure.

[0143] 3.2) By the same method as step 3.1), based on the high-frequency response current of phase A and phase V failure, the d-axis high-frequency response current of phase failure with any phase difference of 150° in the α-β two-phase stationary coordinate system is obtained:

[0144]

[0145] Where Δt represents the current sampling time interval, V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. is the inherent phase loss estimation position error angle when there is a 150° two-phase phase loss fault. This angle has nothing to do with the spatial distribution of the fault phase. K is the estimated position error angle caused by any 150° two-phase failure; 150 It is the d-axis high-frequency current coefficient when there is a two-phase failure with an arbitrary phase difference of 150°.

[0146] According to the high-frequency response current of any two-phase failure with a phase difference of 150° in the α-β two-phase stationary coordinate system, the position error of any two-phase failure with a phase difference of 150° is integrated into the position compensation angle The rotor position angle error when there is a two-phase failure with a phase difference of 150° is obtained by the following formula:

[0147]

[0148] In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 150°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°. It indicates the estimated position error angle caused by a two-phase failure with a phase difference of 150°;

[0149] Among them, the estimated position error angle caused by the two-phase failure with a phase difference of 150° is Set it according to the following formula:

[0150]

[0151] In the formula, It represents the estimated position error angle caused by the two-phase failure with a phase difference of 150°, K d-150 Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q-150 It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. Indicates the angle between the fault phase of the first set of windings and phase A in the two faulty phases;

[0152] Among them, the inherent phase loss estimation position error angle when the two phases are 150° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q-150 , d-axis high-frequency current coefficient K when phase A and phase U are missing d-150 Set them according to the following formulas:

[0153]

[0154] In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase loss fault.

[0155] 3.3) By the same method as step 3.1), based on the high-frequency response current of phase A and phase W when the phase is out of phase, the d-axis high-frequency response current of the phase out of phase with an arbitrary phase difference of 270° in the α-β two-phase stationary coordinate system is obtained:

[0156] Δi d-f2X270 = ±ΔtV inj K 270 sinθ

[0157] In the formula, Δi d-f2X270 It represents the d-axis high-frequency response current when there is a two-phase failure with an arbitrary phase difference of 270°. Δt represents the current sampling time interval. V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system, K 270 is the d-axis high-frequency current coefficient for any 270° two-phase failure.

[0158] According to the high-frequency response current of any two-phase failure with a phase difference of 270° in the α-β two-phase stationary coordinate system, the position error of any two-phase failure with a phase difference of 270° is integrated into the position compensation angle The rotor position angle error is zero when there is a two-phase failure with a phase difference of 270°.

[0159] 3.4) Since any 120° two-phase fault occurs in the same set of windings, the motor only has one set of three-phase windings running at this time. Therefore, when analyzing the inductance, only one set of three-phase windings needs to be analyzed. The d-axis high-frequency current when any 120° two-phase phase failure occurs in the α-β two-phase stationary coordinate system is:

[0160] Δi d-f2X120 = ±ΔtV inj K 120 sinθ

[0161] In the formula, Δi d-f2X120 represents the d-axis high-frequency current when any 120° two-phase failure occurs in the α-β two-phase stationary coordinate system, Δt represents the current sampling time interval, V inj represents the amplitude of the high-frequency square wave voltage, θ represents the electrical angle form of the rotor position, Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system, K 120 is the d-axis high-frequency current coefficient for any 120° two-phase failure.

[0162] According to the d-axis high-frequency response current when a two-phase failure occurs with an arbitrary phase difference of 120° in the α-β two-phase stationary coordinate system, the position error when a two-phase failure occurs with an arbitrary phase difference of 120° is integrated into the position compensation angle The rotor position angle error is zero when there is a two-phase failure with a phase difference of 120°.

[0163] Example 2

[0164] This embodiment provides a simulation example of the control method of the present invention. The control method of this embodiment is implemented based on a second-order generalized integrator and a phase-locked loop.

[0165] Figure 3 is a block diagram of a second-order generalized integrator in the present invention, where ω c Indicates the resonant frequency. In the figure, x1 and x2 are the two output signals of the second-order generalized integrator, v represents the input signal of the second-order generalized integrator, k0 is the gain parameter of the second-order generalized integrator, I sin ,I cos represents two equal-amplitude orthogonal signals reconstructed by a second-order generalized integrator;

[0166] Figure 4 The phase-locked loop structure diagram with angle compensation in the present invention, in which I sin ,I cos represents the sine envelope and cosine envelope of two equal-amplitude orthogonal signals reconstructed by the second-order generalized integrator, Δθ represents the position error, Indicates the estimated speed; represents the estimated position, PI represents the proportional integrator, 1 / s represents the integral link, Indicates the rotor position angle error during a phase failure;

[0167] Figure 5 The frequency adaptive second-order generalized integrator-phase-locked loop block diagram of the present invention; the phase-locked loop estimates the speed The second-order generalized integrator estimates the speed As the resonant frequency ω c .

[0168] In this embodiment, the method of the present invention is simulated and verified in Matlab / Simulink, and the results are as follows: Figure 6 to Figure 8 As shown. Figure 6 As shown, when the dual three-phase permanent magnet synchronous motor does not have a phase failure, after adopting the method of the present invention, when the motor is running smoothly, the estimated position error of the position sensorless control does not exceed 2°, and when the motor speed suddenly increases from 200r / min to 400r / min, the estimated position error does not exceed 4°. Figure 7 As shown in Figure 1, after a phase failure occurs in any phase of the dual three-phase permanent magnet synchronous motor, the estimated position error is always kept within 0 to 4°. Figure 8As shown, when the dual three-phase permanent magnet synchronous motor has a two-phase phase loss fault with a phase difference of 30° and 150°, the estimated position error is always kept within 0 to 9°. When the dual three-phase permanent magnet synchronous motor has a two-phase phase loss fault with a phase difference of 270° and 120°, the estimated position error is always kept within 0 to 4°.

[0169] The above description of the functions and working processes of the present invention in combination with the drawings in the specification is only one of the preferred implementation cases, but the present invention is not limited to the above-mentioned specific functions and working processes. The above-mentioned specific implementation methods are only illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection scope of the present invention.

Claims

1. A position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure, characterized in that: The control method comprises the following steps: S1, injecting a high-frequency square wave voltage into the β-axis of the dual three-phase permanent magnet synchronous motor in the α-β two-phase stationary coordinate system, extracting the d-axis high-frequency response current in the dq synchronous rotating coordinate system, and reconstructing a pair of sinusoidal envelope signals; S2. Setting the rotor position angle error according to the operating condition of the dual three-phase permanent magnet synchronous motor; S3. Use a phase-locked loop to combine the current rotor estimated position, the rotor position angle error and a pair of reconstructed envelope signals to update the rotor estimated position.

2. The position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 1 is characterized in that: The step S2 is specifically as follows: When the dual three-phase permanent magnet synchronous motor operates normally, the rotor position angle error is set to zero; When a phase loss fault occurs in the dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error during the phase loss fault according to the type of the phase loss fault; the types of the phase loss fault include single-phase phase loss fault, two-phase phase loss fault with a phase difference of 30°, two-phase phase loss fault with a phase difference of 150°, two-phase phase loss fault with a phase difference of 270° and two-phase phase loss fault with a phase difference of 120°.

3. The position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 2 is characterized in that: When a single-phase failure occurs in the dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error during the single-phase failure. The rotor position angle error during the single-phase failure is obtained by the following formula: In the formula, Indicates the rotor position angle error when a single-phase failure occurs. represents the estimated position error angle caused by a single-phase failure, Indicates the angle between the fault phase and phase A; The estimated position error angle caused by a single-phase failure is set according to the following formula: In the formula, represents the estimated position error angle caused by a single-phase failure, It represents the angle between the fault phase and phase A, K represents the high-frequency current coefficient when phase A is out of phase, K' represents the high-frequency current coefficient when single-phase is out of phase, L1 represents the first single-phase out of phase coefficient, and L3 represents the second single-phase out of phase coefficient.

4. The position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 2 is characterized in that: When a two-phase failure with a phase difference of 30° occurs in the dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when the two-phase failure with a phase difference of 30° occurs; The rotor position angle error when there is a two-phase failure with a phase difference of 30° is obtained by the following formula: In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 30°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°. It indicates the estimated position error angle caused by a two-phase failure with a phase difference of 30°; Among them, the estimated position error angle caused by the two-phase failure with a phase difference of 30° is Set it according to the following formula: In the formula, It represents the estimated position error angle caused by the two-phase failure with a phase difference of 30°, K d-30 Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q-30 It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. Indicates the angle between the fault phase of the first set of windings and phase A in the two faulty phases; Among them, the inherent phase loss estimation position error angle when the two phases are 30° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q-30 , d-axis high-frequency current coefficient K when phase A and phase U are missing d-30 Set them according to the following formulas: In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 30°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase loss fault.

5. The position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 2 is characterized in that: When a two-phase failure with a phase difference of 150° occurs in the dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when the two-phase failure with a phase difference of 150° occurs; the rotor position angle error when the two-phase failure with a phase difference of 150° occurs is obtained by the following formula: In the formula, It indicates the rotor position angle error when there is a two-phase failure with a phase difference of 150°. Indicates the angle between the fault phase of the first set of windings and phase A in the faulty two-phase system. It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°. It indicates the estimated position error angle caused by a two-phase failure with a phase difference of 150°; Among them, the estimated position error angle caused by the two-phase failure with a phase difference of 150° is Set it according to the following formula: In the formula, It represents the estimated position error angle caused by the two-phase failure with a phase difference of 150°, K d-150 Indicates the d-axis high-frequency current coefficient when phase A and phase U are missing, K q-150 It represents the q-axis high-frequency current coefficient when phase A and phase U are missing. Indicates the angle between the fault phase of the first set of windings and phase A in the two faulty phases; Among them, the inherent phase loss estimation position error angle when the two phases are 150° apart is The q-axis high-frequency current coefficient K when the A-phase and U-phase are missing q-150 , d-axis high-frequency current coefficient K when phase A and phase U are missing d-150 Set them according to the following formulas: In the formula, It represents the inherent phase loss estimated position error angle when there is a two-phase loss fault with a phase difference of 150°, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase loss fault.

6. The position sensorless control method for a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 4 or 5, characterized in that: The first two-phase loss coefficient L4, the second two-phase loss coefficient L5, the third two-phase loss coefficient L6, the fourth two-phase loss coefficient L7, and the high-frequency current coefficient K2 during two-phase loss fault are calculated according to the following formulas: Where, L4 represents the first two-phase loss coefficient, L5 represents the second two-phase loss coefficient, L6 represents the third two-phase loss coefficient, L7 represents the fourth two-phase loss coefficient, L0 represents the mean inductance, L2 represents the difference inductance, L z represents the leakage inductance of the motor, θ represents the electrical angle form of the rotor position, and K2 represents the high-frequency current coefficient when two-phase failure occurs.

7. The position sensorless control method for dual three-phase permanent magnet synchronous motor considering phase failure according to claim 2 is characterized in that: When a dual three-phase permanent magnet synchronous motor has a two-phase loss fault with a phase difference of 270°, the rotor position angle error is set to the rotor position angle error when the two-phase loss fault has a phase difference of 270°; the rotor position angle error when the two-phase loss fault has a phase difference of 270° is set to zero.

8. The position sensorless control method for dual three-phase permanent magnet synchronous motor considering phase failure according to claim 2 is characterized in that: When a dual three-phase permanent magnet synchronous motor has a two-phase loss fault with a phase difference of 120°, the rotor position angle error is set to the rotor position angle error when the two-phase loss fault has a phase difference of 120°; the rotor position angle error when the two-phase loss fault has a phase difference of 120° is set to zero.

9. The position sensorless control method for dual three-phase permanent magnet synchronous motor considering phase failure according to claim 1 is characterized in that: The step S3 comprises the following steps: S3.

1. Use a phase-locked loop, take the sum of the estimated rotor position and the rotor position angle error as the angle of the sine signal and the cosine signal, multiply the sine signal and the cosine signal with the cosine envelope and the sine envelope in the sine envelope signal respectively, and make a difference between the two product values ​​to obtain the position error; S3.2, using the PI regulator to process the position error to obtain the estimated speed; S3.

3. Use an integrator to integrate the estimated rotational speed to obtain a new estimated rotor position, and use the new estimated rotor position to update the estimated rotor position.

10. The position sensorless control method of a dual three-phase permanent magnet synchronous motor considering a phase failure according to claim 9, characterized in that: The phase-locked loop inputs the estimated rotation speed obtained in step S3.2 into a second-order generalized integrator, and the second-order generalized integrator uses the estimated rotation speed as the resonant frequency.

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