A dual three-phase permanent magnet synchronous motor position sensorless control method considering open-phase fault

Abstract

The application discloses a kind of double three-phase permanent magnet synchronous motor position sensorless control methods considering open-phase fault.The method of the present application injects high-frequency square wave voltage to the beta axis of double three-phase permanent magnet synchronous motor in alpha-beta two-phase stationary coordinate system, extracts the high-frequency response current of d-axis in d-q synchronous rotating coordinate, and reconstructs a pair of sinusoidal envelope signals according to the high-frequency response current of d-axis;According to the operating condition of double three-phase permanent magnet synchronous motor, the rotor position angle error is set;The estimated position of rotor is updated using phase-locked loop combined with rotor, rotor position angle error and a pair of reconstructed envelope signals.The present application method realizes the position sensorless control when any one phase, two-phase open-phase fault of double three-phase permanent magnet synchronous motor operates.

Description

Technical Field

[0001] This invention belongs to the field of sensorless control of multiphase permanent magnet synchronous motors, and in particular relates to a sensorless control method for a dual three-phase permanent magnet synchronous motor under phase loss fault. Background Technology

[0002] As a key technology in the industrial field, the greening and intelligent upgrading of AC drive systems is of great significance for achieving carbon peaking and carbon neutrality goals. Multiphase motors, with their high power density, good fault tolerance, and high degree of freedom, are increasingly used in aerospace, marine propulsion, and new energy vehicles. Among them, the dual three-phase permanent magnet synchronous motor, with its two windings phase-shifted by 30°, eliminates the motor's six torque pulsations, resulting in smoother torque operation. Accurate rotor position information is crucial for the motor's control performance during operation. Typically, rotor position information is obtained using mechanical position sensors, but installing mechanical sensors increases the cost and size of the motor system. To address this issue, sensorless control technology is particularly important. Compared to traditional three-phase motors, the high fault tolerance during phase loss faults is a significant advantage of multiphase motors; therefore, sensorless control of dual three-phase permanent magnet synchronous motors during phase loss faults is essential.

[0003] Currently, to address the issue of DC components in high-frequency currents caused by single-axis high-frequency signal injection in a stationary coordinate system for rotor position estimation, most existing methods suppress these components by introducing low-pass filters, thus affecting system bandwidth. Furthermore, for sensorless control of dual three-phase permanent magnet synchronous motors operating under phase-loss faults, existing methods do not analyze the inductance changes after phase loss. However, the inductance matrix contains a wealth of rotor position information, especially when the motor operates under phase loss, as the inductance matrix becomes non-symmetrical. Therefore, the inductance changes after phase loss have unique research value for high-frequency injection sensorless control methods. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults. The method injects a high-frequency square wave voltage along a single axis in a stationary coordinate system, and then extracts position information in a synchronously rotating coordinate system, avoiding the problem of DC components in the high-frequency current. Furthermore, based on the inductance changes when any one or two phases of the dual three-phase permanent magnet synchronous motor are missing, a position compensation method based on a second-order generalized integrator-phase-locked loop is proposed, realizing sensorless control of the dual three-phase permanent magnet synchronous motor during operation with any one or two phase loss faults.

[0005] The technical solution adopted in this invention is as follows:

[0006] I. A sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults

[0007] The control method includes 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 90° phase difference, and input the reconstructed envelope signals into the phase-locked loop.

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

[0010] Step S2 specifically involves:

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

[0012] When a phase loss fault occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when the phase loss fault occurs, according to the type of phase loss fault. The types of phase loss faults 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 loss fault occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error will be... Rotor position angle error set for single-phase loss fault Rotor position angle error during single-phase loss fault The following formula is used to obtain it:

[0014]

[0015] In the formula, This indicates the rotor position angle error during a single-phase loss fault. This represents the estimated position error angle caused by a single-phase loss fault. This indicates the angle between the faulty phase and phase A. The faulty phase can be phase A, phase B, phase C, phase U, phase V, or phase W.

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

[0017]

[0018] In the formula, This represents the estimated position error angle caused by a single-phase loss fault. The angle between the faulty phase and phase A is represented by K, which represents the high-frequency current coefficient when phase A is missing, K' represents the high-frequency current coefficient when a single phase is missing, L1 represents the first single-phase missing coefficient, and L3 represents the second single-phase missing coefficient.

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

[0020]

[0021] In the formula, L1 represents the first single-phase loss coefficient, L3 represents the second single-phase loss coefficient, K represents the high-frequency current coefficient during a single-phase loss fault in phase A, L0 represents the average inductance, L2 represents the differential inductance, and L... z The leakage inductance of a dual three-phase permanent magnet synchronous motor is represented by θ, which represents the electrical angle of the rotor position.

[0022] The mean inductance L0 and the difference inductance L2 are obtained from the d-axis inductance and q-axis inductance in the dq synchronous rotating coordinate system using the following formulas:

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

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

[0025] In the formula, L0 represents the average inductance, L2 represents the differential inductance, and L... d L represents the d-axis inductance in the dq synchronous rotating coordinate system. q This represents the q-axis inductance in the dq synchronous rotating coordinate system.

[0026] b. When a two-phase loss fault with a phase difference of 30° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error will be considered. Rotor position angle error set for a two-phase loss fault with a phase difference of 30° Rotor position angle error during a two-phase loss fault with a phase difference of 30° The following formula is used to obtain it:

[0027]

[0028] In the formula, This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 30°. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 30°. This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°.

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

[0030]

[0031] In the formula, K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°. d-30 K represents the d-axis high-frequency current coefficient during phase A and phase U loss faults. q-30 This represents the q-axis high-frequency current coefficient during phase A and phase U loss faults. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases.

[0032] Among them, the inherent phase loss estimation position error angle during a two-phase phase loss fault with a phase difference of 30° is... The q-axis high-frequency current coefficient K during phase A and phase U loss faults q-30 The d-axis high-frequency current coefficient K during phase A and phase U loss faults d-30 Set them according to the following formulas respectively:

[0033]

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

[0035] The first set of windings includes phase A, phase B, and phase C. These three windings are spatially separated by 120° electrical degrees, together forming a three-phase subsystem in a six-phase motor.

[0036] c. When a two-phase loss fault with a phase difference of 150° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error will be... Rotor position angle error set for a two-phase loss fault with a phase difference of 150° Rotor position angle error during a two-phase loss fault with a phase difference of 150° The following formula is used to obtain it:

[0037]

[0038] In the formula, This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 150°. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 150°. This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°.

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

[0040]

[0041] In the formula, K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°. d-150 K represents the d-axis high-frequency current coefficient during phase A and phase U loss faults. q-150 This represents the q-axis high-frequency current coefficient during phase A and phase U loss faults. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases.

[0042] Among them, the inherent phase loss estimation position error angle during a two-phase phase loss fault with a phase difference of 150° is... The q-axis high-frequency current coefficient K during phase A and phase U loss faults q-150 The d-axis high-frequency current coefficient K during phase A and phase U loss faults d-150 Set them according to the following formulas respectively:

[0043]

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

[0045] The phase loss coefficients L4 (first two phases), L5 (second two phases), L6 (third two phases), L7 (fourth two phases), and K2 (high-frequency current coefficient during a two-phase phase loss fault) are calculated from known parameters using the following formulas:

[0046]

[0047] In the formula, 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 average inductance, L2 represents the differential inductance, and L...z θ 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 during a two-phase loss fault.

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

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

[0050] S3. Use a phase-locked loop to combine the current rotor estimated position and rotor position angle error. The rotor estimated position is updated with a pair of reconstructed envelope signals.

[0051] Step S3 includes the following steps:

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

[0053] S3.2. Using a PI controller, the estimated rotational speed is obtained by proportional and integral processing of the position error;

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

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

[0056] S4. The updated rotor estimated position is input to the input terminal of the phase-locked loop (PLL). The PLL uses the updated rotor estimated position as the current rotor estimated position at the next moment, and then dynamically updates the rotor estimated position according to step S3. At the same time, the updated rotor estimated position is closed-looped into the motor controller using the PLL, replacing the role of the traditional position sensor and realizing sensorless control.

[0057] The beneficial effects of the technical solution of this invention are:

[0058] This invention proposes a sensorless control method for a dual three-phase permanent magnet synchronous motor under phase loss fault, which compensates for the position error caused by phase loss fault and realizes high-precision sensorless control under phase loss fault. Attached Figure Description

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

[0060] Figure 2 This is a schematic diagram of the equivalent two-phase stationary coordinate system during a phase loss fault in this invention;

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

[0062] Figure 4 This is a block diagram of the phase-locked loop structure with angle compensation in this invention;

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

[0064] Figure 6 The diagram shows the simulation results of the speed change of this invention.

[0065] Figure 7 This is a simulation result diagram of any phase loss fault in this invention;

[0066] Figure 8 This is a simulation result diagram of any two-phase loss fault in this invention. Detailed Implementation

[0067] The following describes in detail, with reference to embodiments and accompanying drawings, a sensorless control method for a dual three-phase permanent magnet synchronous motor under phase loss fault according to the present invention.

[0068] This invention proposes a sensorless control method for a dual-three-phase permanent magnet synchronous motor considering phase loss faults. First, a high-frequency square wave voltage is injected into a single axis in a stationary coordinate system. Then, rotor position information is extracted from the high-frequency current in the synchronous rotating coordinate system, avoiding the problem of DC components in the high-frequency current. Second, the inductance changes of the dual-three-phase permanent magnet synchronous motor when any one or two phases are missing are analyzed. Furthermore, a position compensation method based on a second-order generalized integrator-phase-locked loop is proposed, achieving high-precision sensorless control of the dual-three-phase permanent magnet synchronous motor during operation with any one or two phase loss faults.

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

[0070] Example 1

[0071] This embodiment analyzes the inductance changes of a dual three-phase permanent magnet synchronous motor under one-phase and two-phase loss faults, and then predicts the rotor position angle error under different phase loss faults. The specific process is as follows:

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

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

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

[0075]

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

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

[0078]

[0079] In the formula, ψ dqs Let T denote the flux linkage in the dq synchronous rotating coordinate system, and let T denote the transformation matrix, where T = T 6r T 6s T 6r L represents the rotation coordinate transformation matrix. 6s Represents the six-phase inductance coefficient matrix, I 6s Let L denote the sixth-order identity matrix, λ denote the flux linkage coefficient matrix, and L z i represents the leakage inductance of a dual three-phase permanent magnet synchronous motor. d i q L represents the d-axis current and q-axis current in the dq synchronous rotating coordinate system, respectively. d L represents the d-axis inductance in the dq synchronous rotating coordinate system. q This represents the q-axis inductance in the dq synchronous rotating coordinate system. i represents the flux linkage amplitude of a dual three-phase permanent magnet synchronous motor. x i y These 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 The high-frequency voltage representing the α-axis, u βh V represents the high-frequency voltage along the β axis. inj This indicates the amplitude of the high-frequency square wave voltage.

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

[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] In the formula, L0 represents the average inductance, L2 represents the differential inductance, θ represents the electrical angle of the rotor position, and i αh i represents the high-frequency response current along the α-axis in the α-β two-phase stationary coordinate system. βh The β-axis high-frequency response current, u, is represented in the α-β two-phase stationary coordinate system. αhU represents the high-frequency voltage along the α-axis in the α-β two-phase stationary coordinate system. βh This represents the β-axis high-frequency voltage in the α-β two-phase stationary coordinate system.

[0087] The mean inductance L0 and the difference inductance L2 are obtained from the d-axis inductance and q-axis inductance in the dq synchronous rotating coordinate system using the following formulas:

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

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

[0090] In the formula, L0 represents the average inductance, L2 represents the differential inductance, and L... d L represents the d-axis inductance in the dq synchronous rotating coordinate system. q This 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] In the formula, L d L represents the d-axis inductance in the dq synchronous rotating coordinate system. q U represents the q-axis inductance in the dq synchronous rotating coordinate system. dh U represents the high-frequency voltage along the d-axis in the dq synchronous rotating coordinate system. qh i represents the q-axis high-frequency voltage in the dq synchronous rotating coordinate system. dh i represents the high-frequency response current along the d-axis in the dq synchronous rotating coordinate system. qh This represents the high-frequency response current along the q-axis in the dq synchronous rotating coordinate system.

[0094] Mapping the high-frequency square wave voltage onto the dq synchronous rotating coordinate system yields the high-frequency square wave voltage in the dq synchronous rotating coordinate system:

[0095]

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

[0097] By inputting 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, the differential form of the high-frequency response current in the dq synchronous rotating coordinate system is obtained:

[0098]

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

[0100] When the dual three-phase permanent magnet synchronous motor is running normally, the differential form of the high-frequency response current in the dq synchronous rotating coordinate system is discretized to obtain the difference form Δi of the d-axis high-frequency current. d By using the differential form Δi of the d-axis high-frequency current d Symbolic processing is performed to obtain the envelope of the d-axis high-frequency current. This envelope is used as the input signal for a second-order generalized integrator. By reconstructing the envelope, a pair of orthogonal, equal-amplitude sinusoidal envelope signals containing position information are obtained. This pair of sinusoidal envelope signals is input into a phase-locked loop (PLL). The PLL combines the current estimated rotor position with the reconstructed envelope signals to update the estimated rotor position. The updated estimated rotor position is then used as the current estimated rotor position for the next moment. Simultaneously, the updated estimated rotor position is closed-looped into the motor controller, replacing the role of a traditional position sensor and achieving high-precision sensorless control.

[0101] 2) First, establish the inductance matrix in the dq synchronous rotating coordinate system when the A-phase loss fault occurs in the dual three-phase permanent magnet synchronous motor. Then, input the established inductance matrix 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 loss fault occurs. Based on the high-frequency response current when the A-phase loss fault occurs, obtain the high-frequency response current when the single-phase loss fault occurs. Based on the high-frequency response current when the single-phase loss fault occurs, integrate the rotor position angle error when the single-phase loss fault occurs.

[0102] Specifically, the following steps are included:

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

[0104]

[0105] In the formula, L dq-fA This represents the inductance matrix of a dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system, where L0 represents the average inductance, L2 represents the differential inductance, and L... z The leakage inductance of a dual three-phase permanent magnet synchronous motor is represented by θ, which represents the electrical angle of the rotor position.

[0106] 2.2) Input the inductance matrix in the dq synchronous rotating coordinate system under phase A phase loss fault into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system. Combine this with the high-frequency square wave voltage in the dq synchronous rotating coordinate system to obtain the discretized form of the high-frequency response current under phase A phase loss fault:

[0107]

[0108] In the formula, Δi d-fA Δi represents the d-axis high-frequency response current during a phase-loss fault in phase A. q-fA V represents the q-axis high-frequency response current during a phase-loss fault in phase A, Δt represents the sampling time interval of the six-phase current, and V inj θ 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 phase A is missing, L1 represents the first single-phase missing coefficient, and L3 represents the second single-phase missing coefficient.

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

[0110]

[0111] In the formula, L1 represents the first single-phase loss coefficient, L3 represents the second single-phase loss coefficient, K represents the high-frequency current coefficient during a single-phase loss fault in phase A, L0 represents the average inductance, L2 represents the differential inductance, and L... z The leakage inductance of a dual three-phase permanent magnet synchronous motor is represented by θ, which represents the electrical angle of the rotor position.

[0112] 2.3) Establish an equivalent two-phase stationary coordinate system under a single-phase phase loss fault. Figure 2 This is a schematic diagram of the equivalent two-phase stationary coordinate system during a phase loss fault in this invention. Figure 2 In the diagram, 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, This indicates the angle between the faulty phase and phase A. The faulty phase can be phase A, phase B, phase C, phase U, phase V, or phase W. The angle between the faulty phase and phase A is used to determine the angle between them. The high-frequency current during operation under a single-phase loss fault in an equivalent two-phase stationary coordinate system is obtained:

[0114]

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

[0116] Based on the high-frequency current during operation of a single-phase-loss fault in an equivalent two-phase stationary coordinate system, the high-frequency response current during operation of a single-phase-loss fault in an α-β two-phase stationary coordinate system is obtained:

[0117]

[0118]

[0119] In the formula, Δi d-fX1 This represents the d-axis high-frequency response current during a single-phase loss fault, where Δt represents the current sampling time interval, V. inj This indicates the amplitude of the high-frequency square wave voltage. This represents the estimated position error angle caused by a single-phase loss fault. The angle between the faulty phase and phase A is represented by K, which represents the high-frequency current coefficient when phase A is missing, K' represents the high-frequency current coefficient when a single phase is missing, L1 represents the first single-phase missing coefficient, and L3 represents the second single-phase missing coefficient.

[0120] 2.4) Based on the high-frequency current during single-phase loss fault operation in the α-β two-phase stationary coordinate system, the position error of the single-phase loss fault is integrated into a position compensation angle. The rotor position angle error during a single-phase loss fault is obtained using the following formula:

[0121]

[0122] In the formula, This indicates the rotor position angle error during a single-phase loss fault. This represents the estimated position error angle caused by a single-phase loss fault. This indicates the angle between the faulty phase and phase A. The faulty phase can be 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 under phase loss faults of phases A and U, phase loss of phases A and V, and phase loss of phases A and W, and input the high-frequency voltage equations respectively to obtain the high-frequency response current under different phase loss faults. Based on the high-frequency response current under phase loss faults of phases A and U, obtain the high-frequency response current under phase loss faults of any two phases with a phase difference of 30°. Based on the high-frequency response current under phase loss faults of phases A and V, obtain the high-frequency response current under phase loss faults of any two phases with a phase difference of 150°. Based on the high-frequency response current under phase loss faults of phases A and W, obtain the high-frequency response current under phase loss faults of any two phases with a phase difference of 270°. Establish the high-frequency response current under phase loss faults of any phase difference of 120°. Based on the high-frequency response current under phase loss faults of any two phases with a phase difference of 30°, 150°, 270°, and 120°, integrate the high-frequency response current under phase loss faults of any two phases with a phase difference of 30°, 150°, 270°, and 120° to obtain the rotor position angle error under phase loss faults of any two phases with a phase difference of 30°, 150°, 270°, and 120°.

[0124] 3.1) The rotor position angle error under a two-phase loss fault with an arbitrary phase difference of 30° is obtained through the following steps:

[0125] The inductance matrix of a dual three-phase permanent magnet synchronous motor in the dq synchronous rotating coordinate system is established when phases A and U are missing. This matrix is ​​then input into the relationship between the high-frequency square wave voltage and the high-frequency response current in the dq synchronous rotating coordinate system. Combining this with the high-frequency square wave voltage in the dq synchronous rotating coordinate system, the differential form of the high-frequency response current when phases A and U are missing is obtained:

[0126]

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

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

[0129]

[0130] In the formula, 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 average inductance, L2 represents the differential inductance, and L... z θ 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 during a two-phase loss fault.

[0131] Based on trigonometric relationships, the high-frequency response currents during phase A and phase U phase loss faults are simplified to obtain the simplified high-frequency response currents during phase A and phase U phase loss faults:

[0132]

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

[0134] Among them, the inherent phase loss estimation position error angle during a two-phase phase loss fault with a phase difference of 30° is... The q-axis high-frequency current coefficient K during phase A and phase U loss faults q The d-axis high-frequency current coefficient K during phase A and phase U loss faults d Set them according to the following formulas respectively:

[0135]

[0136] In the formula, L4 represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 30°. L5 represents the first two-phase phase loss coefficient, L6 represents the second two-phase phase loss coefficient, L7 represents the third two-phase phase loss coefficient, and L8 represents the fourth two-phase phase loss coefficient.

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

[0138]

[0139] In the formula, Δi d-f2X30This represents the high-frequency response current under a two-phase loss fault with an arbitrary phase difference of 30°, where Δt represents the current sampling time interval, and V. inj The amplitude of the high-frequency square wave voltage is represented by θ, which represents the electrical angle of the rotor position. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This represents the inherent phase loss estimation position error angle for a two-phase phase loss fault with a phase difference of 30°. This angle is independent of the spatial distribution of the faulty phases. This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°.

[0140] Based on the high-frequency response current of a two-phase phase loss fault with an arbitrary phase difference of 30° in the α-β two-phase stationary coordinate system, the position error of the two-phase phase loss fault with an arbitrary phase difference of 30° is integrated into the position compensation angle. The rotor position angle error during a two-phase loss fault with a phase difference of 30° is obtained by the following formula:

[0141]

[0142] In the formula, This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 30°. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 30°. K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°. 30 Let be the d-axis high-frequency current coefficient for any 30° two-phase loss fault.

[0143] 3.2) Using the same method as in step 3.1), obtain the d-axis high-frequency response current for a two-phase phase loss fault with an arbitrary phase difference of 150° in the α-β two-phase stationary coordinate system based on the high-frequency response currents during phase A and phase V phase loss faults:

[0144]

[0145] In the formula, Δt represents the current sampling time interval, V inj The amplitude of the high-frequency square wave voltage is represented by θ, which represents the electrical angle of the rotor position. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This is the inherent phase loss estimation position error angle for a 150° two-phase phase loss fault. This angle is independent of the spatial distribution of the faulty phases. K represents the estimated position error angle caused by any 150° two-phase loss fault; 150 The d-axis high-frequency current coefficient is given when there is a two-phase loss fault with an arbitrary phase difference of 150°.

[0146] Based on the high-frequency response current of a two-phase phase loss fault with an arbitrary phase difference of 150° in the α-β two-phase stationary coordinate system, the position error of the two-phase phase loss fault with an arbitrary phase difference of 150° is integrated into the position compensation angle. The rotor position angle error during a two-phase loss fault with a phase difference of 150° is obtained by the following formula:

[0147]

[0148] In the formula, This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 150°. This indicates the angle between the faulty phase of the first winding and phase A in the two faulty phases. This represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 150°. This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°.

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

[0150]

[0151] In the formula, K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°. d-150 K represents the d-axis high-frequency current coefficient during phase A and phase U loss faults. q-150 This represents the q-axis high-frequency current coefficient during phase A and phase U loss faults. This indicates the angle between the faulty phase of the first winding in the two faulty phases and phase A.

[0152] Among them, the inherent phase loss estimation position error angle during a two-phase phase loss fault with a phase difference of 150° is... The q-axis high-frequency current coefficient K during phase A and phase U loss faults q-150 The d-axis high-frequency current coefficient K during phase A and phase U loss faults d-150 Set them according to the following formulas respectively:

[0153]

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

[0155] 3.3) Using the same method as in step 3.1), obtain the d-axis high-frequency response current for a two-phase phase loss fault with an arbitrary phase difference of 270° in the α-β two-phase stationary coordinate system based on the high-frequency response currents of phase A and phase W during phase loss faults:

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

[0157] In the formula, Δi d-f2X270 This represents the d-axis high-frequency response current under a two-phase loss fault with an arbitrary phase difference of 270°, where Δt represents the current sampling time interval, and V. inj The amplitude of the high-frequency square wave voltage is represented by θ, which represents the electrical angle of the rotor position. K represents the angle between the faulty phase and phase A of the first winding in the two faulty phases. 270 The d-axis high-frequency current coefficient is given when there is a two-phase loss fault at any 270° angle.

[0158] Based on the high-frequency response current of a two-phase phase loss fault with an arbitrary phase difference of 270° in the α-β two-phase stationary coordinate system, the position error of the two-phase phase loss fault with an arbitrary phase difference of 270° is integrated into the position compensation angle. The rotor position angle error is zero when there is a two-phase loss fault with a phase difference of 270°.

[0159] 3.4) Since any 120° two-phase fault occurs in the same winding, only one set of three-phase windings operates 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 under any 120° two-phase loss fault 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 V represents the d-axis high-frequency current during a two-phase loss fault at any 120° angle in the α-β two-phase stationary coordinate system, where Δt represents the current sampling time interval. inj The amplitude of the high-frequency square wave voltage is represented by θ, which represents the electrical angle of the rotor position. K represents the angle between the faulty phase and phase A of the first winding in the two faulty phases. 120 The d-axis high-frequency current coefficient is given when there is a two-phase loss fault at any 120° angle.

[0162] Based on the d-axis high-frequency response current of a two-phase phase loss fault with an arbitrary phase difference of 120° in the α-β two-phase stationary coordinate system, the position error of the two-phase phase loss fault 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 loss fault 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 in this embodiment is implemented based on a second-order generalized integrator and a phase-locked loop.

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

[0166] Figure 4 This is a block diagram of the phase-locked loop structure with angle compensation in this invention. In the diagram, I... sin I cos Let Δθ represent the sine and cosine envelopes of the two orthogonal signals with equal amplitude reconstructed by the second-order generalized integrator, and let Δθ represent the position error. Indicates the estimated rotational speed; This indicates the estimated position, PI represents the proportional-integral converter, and 1 / s represents the integral element. This indicates the rotor position angle error during a phase loss fault.

[0167] Figure 5 This is a block diagram of the frequency adaptive second-order generalized integrator-phase-locked loop of the present invention; the phase-locked loop estimates the rotational speed. The input is fed into a second-order generalized integrator, which estimates the rotational speed. As the resonant frequency ω c .

[0168] In this embodiment, the method of the present invention is verified by simulation in Matlab / Simulink, and the results are as follows: Figures 6-8 As shown. Figure 6 As shown, when a dual three-phase permanent magnet synchronous motor does not experience a phase loss fault, after adopting the method of this invention, the estimated position error without position sensor control does not exceed 2° during stable motor operation, and the estimated position error does not exceed 4° when the motor speed suddenly increases from 200 r / min to 400 r / min. Figure 7 As shown, after a phase loss fault occurs in any one phase of a dual three-phase permanent magnet synchronous motor, the estimated position error remains within 0 to 4°. Figure 8As shown, when a two-phase loss fault occurs in a dual three-phase permanent magnet synchronous motor with a phase difference of 30° and 150°, the estimated position error remains within 0 to 9°. When a two-phase loss fault occurs with a phase difference of 270° and 120°, the estimated position error remains within 0 to 4°.

[0169] The above description of the function and working process of the present invention in conjunction with the accompanying drawings is only one preferred embodiment. However, the present invention is not limited to the specific function and working process described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these are within the scope of protection of the present invention.

Claims

1. A sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults, characterized in that: The control method includes the following steps: 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, extract the high-frequency response current of the d axis in the dq synchronous rotating coordinate system, and reconstruct a pair of sinusoidal envelope signals. S2. Set the rotor position angle error according to the operating status of the dual three-phase permanent magnet synchronous motor; S3. Use a phase-locked loop to update the estimated rotor position by combining the current estimated rotor position, rotor position angle error, and a pair of reconstructed envelope signals; Step S2 specifically involves: When the dual three-phase permanent magnet synchronous motor is running normally, the rotor position angle error is set to zero; When a phase loss fault occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when the phase loss fault occurs, according to the type of phase loss fault. The types of phase loss faults include single 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°. When a single-phase loss fault occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error during a single-phase loss fault. The rotor position angle error during a single-phase loss fault is obtained using the following formula: In the formula, Δφ com-1 Δφ1 represents the estimated position angle error caused by a single-phase loss fault, and φ represents the rotor position angle error during a single-phase loss fault. x1 This indicates the angle between the faulty phase and phase A; The estimated position error angle Δφ1 caused by a single-phase loss fault is set according to the following formula: In the formula, Δφ1 represents the estimated position error angle caused by a single-phase loss fault, and φ x1 The angle between the faulty phase and phase A is represented by K, where K represents the high-frequency current coefficient during a phase-loss fault in phase A. L1 represents the high-frequency current coefficient during a single-phase loss fault, and L3 represents the first single-phase loss coefficient. When a two-phase loss fault with a phase difference of 30° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when a two-phase loss fault with a phase difference of 30° occurs. The rotor position angle error during a two-phase loss fault with a phase difference of 30° is obtained by the following formula: In the formula, Δφ com-30 This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 30°. Δφ represents the angle between the faulty phase and phase A of the first winding in the two faulty phases. 30 The inherent phase loss estimation position error angle, Δφ, represents the phase loss angle when there is a two-phase phase loss fault with a phase difference of 30°. 2-30 This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°. Among them, the estimated position error angle Δφ caused by a two-phase loss fault with a phase difference of 30° is one of them. 2-30 Set it according to the following formula: Δφ 2-30 =arctan[(K q-30 sinφ x2 ) / (K d-30 cosφ x2 )] In the formula, Δφ 2-30 K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 30°. d-30 K represents the d-axis high-frequency current coefficient during phase A and phase U loss faults. q-30 This represents the q-axis high-frequency current coefficient during phase A and phase U loss faults. This indicates the angle between the faulty phase of the first winding in the two faulty phases and phase A. Among them, the inherent phase loss estimation position error angle Δφ during a two-phase phase loss fault with a phase difference of 30° is... 30 The q-axis high-frequency current coefficient K during phase A and phase U loss faults q-30 The d-axis high-frequency current coefficient K during phase A and phase U loss faults d-30 Set them according to the following formulas respectively: In the formula, Δφ 30 L4 represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 30°, L5 represents the first two-phase phase loss coefficient, L6 represents the third two-phase phase loss coefficient, L7 represents the fourth two-phase phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase phase loss fault. When a two-phase loss fault with a phase difference of 150° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when a two-phase loss fault with a phase difference of 150° occurs. When a two-phase loss fault with a phase difference of 270° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when a two-phase loss fault with a phase difference of 270° occurs; the rotor position angle error when a two-phase loss fault with a phase difference of 270° is set to zero. When a two-phase loss fault with a phase difference of 120° occurs in a dual three-phase permanent magnet synchronous motor, the rotor position angle error is set to the rotor position angle error when a two-phase loss fault with a phase difference of 120° occurs; the rotor position angle error when a two-phase loss fault with a phase difference of 120° occurs is set to zero.

2. The sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults according to claim 1, characterized in that: The rotor position angle error during a two-phase loss fault with a phase difference of 150° is obtained by the following formula: In the formula, Δφ com-150 This indicates the rotor position angle error when there is a two-phase loss fault with a phase difference of 150°. Δφ represents the angle between the faulty phase and phase A of the first winding in the two faulty phases. 150 The inherent phase loss estimation position error angle, Δφ, represents the phase loss angle when there is a two-phase phase loss fault with a phase difference of 150°. 2-150 This represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°. Among them, the estimated position error angle Δφ caused by a two-phase loss fault with a phase difference of 150° is 2-150 Set it according to the following formula: Δφ 2-150 =arctan[(K q-150 sinφ x2 ) / (K d-150 cosφ x2 )] In the formula, Δφ 2-150 K represents the estimated position error angle caused by a two-phase loss fault with a phase difference of 150°. d-150 K represents the d-axis high-frequency current coefficient during phase A and phase U loss faults. q-150 This represents the q-axis high-frequency current coefficient during phase A and phase U loss faults. This indicates the angle between the faulty phase of the first winding in the two faulty phases and phase A. Among them, the inherent phase loss estimation position error angle Δφ when there is a two-phase phase loss fault with a phase difference of 150° 150 The q-axis high-frequency current coefficient K during phase A and phase U loss faults q-150 The d-axis high-frequency current coefficient K during phase A and phase U loss faults d-150 Set them according to the following formulas respectively: In the formula, Δφ 150 L4 represents the inherent phase loss estimation position error angle when there is a two-phase phase loss fault with a phase difference of 150°, L5 represents the first two-phase phase loss coefficient, L6 represents the third two-phase phase loss coefficient, L7 represents the fourth two-phase phase loss coefficient, and K2 represents the high-frequency current coefficient when there is a two-phase phase loss fault.

3. The sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults according to claim 1 or 2, characterized in that: The phase loss coefficients L4 (first two phases), L5 (second two phases), L6 (third two phases), L7 (fourth two phases), and K2 (high-frequency current coefficient during a two-phase phase loss fault) are calculated using the following formulas: In the formula, 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 average inductance, L2 represents the differential inductance, and L... z θ 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 during a two-phase loss fault.

4. The sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults according to claim 1, characterized in that: Step S3 includes the following steps: S3.1 Using a phase-locked loop, the sum of the estimated rotor position and the rotor position angle error is used as the angle of the sine signal and cosine signal. The sine signal and cosine signal are multiplied by the cosine envelope and sine envelope in the sine envelope signal, respectively. The difference between the two product values ​​is used to obtain the position error. S3.

2. The estimated rotational speed is obtained by processing the position error using a PI controller; S3.

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

5. The sensorless control method for a dual three-phase permanent magnet synchronous motor considering phase loss faults according to claim 4, characterized in that: The phase-locked loop inputs the estimated rotational speed obtained in step S3.2 into a second-order generalized integrator, which uses the estimated rotational speed as the resonant frequency.

Images