A-phase and U-phase open-circuit fault-tolerant control method and system for dual three-phase permanent magnet synchronous motor

Abstract

The invention relates to the technical field of permanent magnet synchronous motor control, in particular to a dual three-phase permanent magnet synchronous motor A-phase and U-phase open-circuit fault-tolerant control method, which comprises the following steps: S1, acquiring voltage and current data of a dual three-phase permanent magnet synchronous motor under an A-phase and U-phase open-circuit fault; s2, acquiring components of current harmonics under the A-phase and U-phase open-circuit faults, and acquiring harmonic characteristic information through the components of the current harmonics; s3, based on the harmonic characteristic information, current harmonics are suppressed through a multiple proportional-integral quasi-resonance controller; and S4, converting the voltage data into a static coordinate system, calculating to obtain voltage vectors after A and U phase open circuits in the static coordinate system, dividing the distribution of the voltage vectors in the static coordinate system into eight sectors, and calculating the duty ratio of each sector, the application designs a post-fault SVPWM algorithm, the SVPWM algorithm is expanded to a fault state, and the A and U phase open circuit faults can be processed.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motor control, and in particular to a method and system for open-circuit fault-tolerant control of A and U phases of a dual three-phase permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motor is a widely used type of motor, which is favored for its efficient energy conversion rate, compact size and low maintenance requirements. As an advanced power source, it plays an important role in industrial automation, transportation and other fields. In the future, we are expected to see more innovative results emerge to promote the continuous progress and development of this field. Compared with the traditional three-phase motor system, the dual three-phase permanent magnet synchronous motor has the advantages of high power density, high reliability, low torque pulsation and low voltage and high power. It has more prominent advantages in high power and high reliability requirements. In addition, when the neutral point of the dual three-phase permanent magnet synchronous motor is isolated, the dual three-phase permanent magnet synchronous motor with two sets of windings connected by 30° phase shift eliminates the zero-sequence current and simplifies the difficulty of controller design.

[0003] About 38% of the faults of dual three-phase permanent magnet synchronous motors in AC variable speed transmission are caused by power semiconductor failures. Currently, for the fault-tolerant control of multi-phase motors, many researchers focus on single-phase open circuit failures. However, two-phase open circuit failures, as secondary failures caused by single-phase open circuit failures, often occur in AC variable speed transmission systems, and there is a lack of response solutions to this failure in the market. Summary of the invention

[0004] The purpose of the present invention is to provide a dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method and system, which solves the torque and speed pulsation problem of the dual three-phase permanent magnet synchronous motor during operation after the A, U phases are open circuited. The proposed SVPWM algorithm after the A, U phases are open circuited and the matching harmonic suppression strategy can effectively suppress the current harmonics. When the current rating remains unchanged, the system can still maintain a certain load capacity after a fault, ensuring the stable operation of the dual three-phase permanent magnet synchronous motor after a fault after two phases are open circuited.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for open-circuit fault-tolerant control of phases A and U of a dual three-phase permanent magnet synchronous motor, comprising the following steps: S1, obtaining voltage and current data of the dual three-phase permanent magnet synchronous motor under A and U phase open circuit fault; S2. Obtain the components of current harmonics under the A and U phase open circuit faults according to the voltage and current data, and obtain harmonic characteristic information through the components of current harmonics; S3, based on the harmonic characteristic information, suppressing the current harmonics through a multiple proportional integral quasi-resonant controller; S4, obtaining voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, converting the voltage data to a stationary coordinate system, calculating the voltage vector after the A and U phases are open-circuited in the stationary coordinate system, dividing the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculating the duty cycle of each sector; S5. Generate a PWM signal according to the duty cycle of each sector to control the inverter to output a new voltage vector, and control the operation of the motor according to the new voltage vector.

[0006] The present invention is further configured such that the components of the current harmonics include the terminal voltage harmonics and the back electromotive force harmonics introduced by the motor body structure: The harmonics in the dual three-phase permanent magnet synchronous motor control system mainly come from the terminal voltage harmonics caused by the inverter nonlinearity and the back electromotive force harmonics introduced by the motor body structure.

[0007] In order to prevent the inverter upper and lower bridge arms from being directly connected, PWM will have a certain dead zone, and the IGBT turn-on and turn-off process will also have a certain time. The terminal voltage harmonics caused by these inverter nonlinearities are quantitatively calculated through the terminal voltage distortion, and the formula is: ; In the formula, ∆ u n For the n Phase terminal voltage distortion, ∆ u n(1） For the n Phase fundamental voltage distortion, No. n The initial phase of the fundamental current, ∆ u d The voltage distortion coefficient caused by the nonlinearity of the inverter, k is the harmonic order, is the angular velocity, t is the time. Its expansion in the time domain is mainly low-frequency odd harmonics.

[0008] After the phase is broken, the current changes, the current in the six-phase winding is no longer symmetrical, and the back electromotive force generated by the fundamental current has changed. It is not just the superposition of the kth harmonic back electromotive force. The back electromotive force generated by the fundamental current in each phase after the fault is; The quantitative calculation formula of back EMF harmonics is: ; In the formula, e n For the n The reverse potential of the phase, O + is the set of all positive odd numbers, The fundamental magnetomotive force k The amplitude of the subharmonic back EMF, For the nThe initial phase of the fundamental current, where the first phase is the harmonic back electromotive force generated by the fundamental magnetomotive force, , They are n Positive and negative sequence generation of subharmonic magnetomotive force k The amplitude of the subharmonic back EMF, , They are k Positive and negative sequence generation of subharmonic magnetomotive force k The first phase of the subharmonic back EMF, the second and third phases are the positive and negative sequence harmonic back EMF generated by the harmonic magnetomotive force; the harmonic back EMF is also an odd harmonic.

[0009] The present invention is further configured that the steps of obtaining harmonic characteristic information through the components of current harmonics are: S1, transform the harmonic current into the dq coordinate system by modifying the reduced-order transformation matrix and removing the elements related to the zero-sequence component in the matrix; Taking the third harmonic as an example, the calculation formula is: ; S2, obtain the harmonic current dq Coordinate system mapping; With the third harmonic current dq Taking the mapping of the coordinate system as an example, the calculation formula is: ; S3, through the harmonic current dq The mapping of the coordinate system obtains the harmonic order.

[0010] After the third harmonic current is transformed, dq The components of the coordinate system are the superposition of the second harmonic and the fourth harmonic. Similarly, other odd harmonics can also be mapped after matrix transformation. The harmonics existing in the natural coordinate system are d- q The correspondence between the harmonics in the coordinate system, the odd harmonics in the phase current in the natural coordinate system are mapped to dq After the coordinate system is established, it is divided into positive sequence components and negative sequence components, and both are 2k (k=1,2…) harmonics.

[0011] The present invention is further configured that the steps of suppressing current harmonics by using a multiple proportional integral quasi-resonant controller are: S1, bringing the harmonic order into the transfer function of the multiple proportional-integral quasi-resonant controller; The transfer function of the multiple proportional-integral quasi-resonant controller is: ; In the formula, K p is the proportional coefficient of the PI controller,K i is the integration coefficient, oh 0 is the fundamental frequency, K rh is the resonant gain, oh ch is the resonant angular frequency, and h is the harmonic order.

[0012] S2, suppresses input current harmonics through multiple proportional-integral quasi-resonant controller transfer functions; The calculation formula is: y(s) = G(s)*U(s); Wherein, U(s) is the input current harmonic signal, G(s) is the discretized transfer function of the multiple proportional-integral quasi-resonant controller, and y(s) is the output signal.

[0013] The present invention is further configured to analyze only the multiple resonant controller for the convenience of analysis. The accuracy of the resonant point of the discretized resonant controller needs to be guaranteed, so the resonant controller is discretized by using a pre-difference bilinear change. The transfer function of the discretized multiple proportional-integral quasi-resonant controller is: ; Where Ts is the sampling period of the system; ; ; ; .

[0014] The present invention is further configured to obtain voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, convert the voltage data to a stationary coordinate system, calculate the voltage vector after the A and U phases are open-circuited in the stationary coordinate system, divide the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculate the duty cycle of each sector as follows: S1, obtaining the relationship between the phase voltage of the motor and the inverter switch state after the fault; The calculation formula is: ; S2, by modifying the reduced-order transformation matrix, applying the modified reduced-order matrix T αβ AU , transform the phase voltage to the stationary coordinate system; The calculation formula is: ; S3, calculating the relationship between the voltage vector and the switching function in the stationary coordinate system by using the method of modifying the reduced-order transformation matrix and the mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit fault; The calculation formula is: ; In the formula, S B、 S c、 S v and S w Indicates the switching state of the inverter bridge arm. "1" means the upper bridge arm is turned on and the lower bridge arm is turned off; "0" means the lower bridge arm is turned on and the upper bridge arm is turned off. S B、 S c、 S v and S w Substitute the 16 states of the A and U phases into the distribution of the voltage vector after the A and U phases are open-circuited. The entire plane is divided into 8 sectors according to the distribution of the voltage vector in the stationary coordinate system, and the boundary vector of the sector is selected as v 1. v 2 The general formula for the duty cycle of each sector in the stationary coordinate system is obtained: ; In the formula f 1. f 2 for v 1. v 2 is the angle between the reference vector and the α axis, θ is the angle between the reference vector and the α axis, | v ref | is the modulus of the reference vector, | v 1|、| v 2| is the modulus length of each sector boundary vector. D1 and D2 represent the occupation time of non-zero vectors v1 and v2 respectively. They determine the time ratio of the two non-zero vectors being activated in the whole control cycle. D1 represents the occupation time of zero vector. Zero vector refers to the state where all inverter switches are turned off. Its action time is used to transition to the next voltage vector and helps to maintain the balance of DC side voltage. By reasonably arranging the action time of different voltage vectors, any reference voltage vector can be synthesized. These voltage vectors are used to synthesize the required voltage waveform in motor control, thereby controlling the running state of the motor.

[0015] The present invention is further configured that the steps of the method for correcting the reduced-order transformation matrix are: S1, use the zero-sequence flux to correct the fundamental flux, inject the zero-sequence component into the first two rows of the original matrix, and correct the reduced-order Clark matrix; The calculation formula is: ; S2, reduce the Park matrix; The formula is: ; S3, obtain the corrected magnetic flux; The formula is: ; In the formula, P α0 、P α0 It is the projection of the rotor permanent magnet in the stationary coordinate system during normal operation.

[0016] The present invention is further configured that the mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit faults includes a voltage equation and an electromagnetic torque equation under the A and U phase open circuit faults; The voltage equation is: ; The formula of the electromagnetic torque equation is: 9. ; in, is the d-axis component of the stator voltage, is the q-axis component of the stator voltage, is the d-axis component of the stator current, is the q-axis component of the stator current, R is the stator resistance; is the electrical angular velocity; is the d-axis inductance component, is the q-axis inductance component. is the permanent magnet flux of the motor.

[0017] The present invention also discloses a dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control system, including a speed outer loop and a current inner loop; The speed outer loop includes a PI controller to output the reference q Shaft current; The current inner loop includes a multiple proportional integral quasi-resonant controller and a feedforward decoupling control. The internal structure of the current inner loop is composed of Figure 2 It is used to output the reference dq axis voltage signal and send it to the SVPWM control algorithm module under fault conditions to calculate the action time of each vector, such as Figure 4 As shown, the output is finally sent to the motor through the inverter to complete the fault-tolerant control of the open circuit of the A and U phases of the dual three-phase permanent magnet synchronous motor.

[0018] The beneficial effects of this application are: (1) This application aims to correct the permanent magnet flux to be circular after the fault, designs a method for correcting the reduced-order transformation matrix, and designs a mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit faults, ensuring that the mathematical model of the dual three-phase permanent magnet synchronous motor is consistent in the fundamental wave plane before and after the fault, which is convenient for building unified control during normal operation and fault operation; (2) This application uses the method of modifying the reduced-order transformation matrix to calculate the distribution of the voltage vector, and based on the distribution of the voltage vector, designs a post-fault SVPWM algorithm, expands the SVPWM algorithm to the fault state, and can handle the A and U phase open circuit faults; (3) This application analyzes the harmonic components in the current of the motor after a fault and designs a multiple proportional-integral quasi-resonant controller to suppress harmonics. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the control block diagram of the dual three-phase permanent magnet synchronous motor after the A and U phases open circuit fault; Figure 2 This is the block diagram of the inner loop multiple proportional-integral quasi-resonant control of the A and U phase open-circuit fault current.

[0020] Figure 3 It is the distribution diagram of the basic voltage vector after the A and U phase open circuit fault; Figure 4 This is the action sequence of each sector switch controlled by SVPWM after an open-circuit fault of phases A and U.

[0021] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0023] The design concept of the present invention is that about 38% of the faults of dual three-phase permanent magnet synchronous motors in AC variable speed transmission are caused by power semiconductor failures. Currently, for the fault-tolerant control of multi-phase motors, many researchers focus on single-phase open circuit failures. However, two-phase open circuit failures, as secondary failures caused by single-phase open circuit failures, often occur in AC variable speed transmission systems, and there is a lack of response solutions to this failure on the market.

[0024] Next, the present invention will be described in detail.

[0025] like Figure 1-Figure 4 As shown, the present application provides: a dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method, comprising the following steps: S1, obtaining voltage and current data of the dual three-phase permanent magnet synchronous motor under A and U phase open circuit fault; S2. Obtain the components of current harmonics under the A and U phase open circuit faults according to the voltage and current data, and obtain harmonic characteristic information through the components of current harmonics; S3, based on the harmonic characteristic information, suppressing the current harmonics through a multiple proportional integral quasi-resonant controller; S4, obtaining the voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, converting the voltage data to the stationary coordinate system, calculating the voltage vector after the A and U phases are open-circuited in the stationary coordinate system, dividing the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculating the duty cycle of each sector; this step is the SVPWM control algorithm; S5. Generate a PWM signal according to the duty cycle of each sector to control the inverter to output a new voltage vector. Control the operation of the motor according to the new voltage vector. The duty cycle of each sector has been determined in the previous step. Based on this, bring the data into the mathematical model of the permanent magnet synchronous motor under the open circuit fault of A and U phases. The required current is obtained through the electromagnetic torque equation, and the required voltage can be obtained through the voltage equation.

[0026] The present invention is further configured such that the components of the current harmonics include the terminal voltage harmonics and the back electromotive force harmonics introduced by the motor body structure: The harmonics in the dual three-phase permanent magnet synchronous motor control system mainly come from the terminal voltage harmonics caused by the inverter nonlinearity and the back electromotive force harmonics introduced by the motor body structure.

[0027] In order to prevent the inverter upper and lower bridge arms from being directly connected, PWM has a certain dead zone, and the IGBT turn-on and turn-off process also has a certain time. These inverter nonlinearities will cause The terminal voltage harmonics are calculated quantitatively through the terminal voltage distortion, and the formula is: ; In the formula, ∆ u n For the n Phase terminal voltage distortion, ∆ u n(1） For the n Phase fundamental voltage distortion, No. n The initial phase of the fundamental current, ∆ u d The voltage distortion coefficient caused by the nonlinearity of the inverter, k is the harmonic order, is the angular velocity, t is the time. Its expansion in the time domain is mainly low-frequency odd harmonics.

[0028] After the phase is broken, the current changes, the current in the six-phase winding is no longer symmetrical, and the back electromotive force generated by the fundamental current has changed. It is not just the superposition of the kth harmonic back electromotive force. The back electromotive force generated by the fundamental current in each phase after the fault is; The quantitative calculation formula of back EMF harmonics is: ; In the formula, e n For the n The reverse potential of the phase, O + is the set of all positive odd numbers, The fundamental magnetomotive force k The amplitude of the subharmonic back EMF, For the n The initial phase of the fundamental current, where the first phase is the harmonic back electromotive force generated by the fundamental magnetomotive force, , They are n Positive and negative sequence generation of subharmonic magnetomotive force k The amplitude of the subharmonic back EMF, , They are k Positive and negative sequence generation of subharmonic magnetomotive force k The first phase of the subharmonic back EMF, the second and third phases are the positive and negative sequence harmonic back EMF generated by the harmonic magnetomotive force; the harmonic back EMF is also an odd harmonic.

[0029] The present invention is further configured that the steps of obtaining harmonic characteristic information through the components of current harmonics are: S1, transform the harmonic current into the dq coordinate system by modifying the reduced-order transformation matrix and removing the elements related to the zero-sequence component in the matrix; Taking the third harmonic as an example, the calculation formula is: ; S2, obtain the harmonic current dq Coordinate system mapping; With the third harmonic current dq Taking the mapping of the coordinate system as an example, the calculation formula is: ; S3, through the harmonic current dq The mapping of the coordinate system obtains the harmonic order.

[0030] After the third harmonic current is transformed, dq The components of the coordinate system are the superposition of the second harmonic and the fourth harmonic. Similarly, other odd harmonics can also be mapped after matrix transformation. The harmonics existing in the natural coordinate system are d- qThe correspondence between the harmonics in the coordinate system, the odd harmonics in the phase current in the natural coordinate system are mapped to dq After the coordinate system is established, it is divided into positive sequence components and negative sequence components, and both are 2k (k=1,2…) harmonics.

[0031] The present invention is further configured that the steps of suppressing current harmonics by using a multiple proportional integral quasi-resonant controller are: S1, bringing the harmonic order into the transfer function of the multiple proportional-integral quasi-resonant controller; The transfer function of the multiple proportional-integral quasi-resonant controller is: ; In the formula, K p is the proportional coefficient of the PI controller, K i is the integration coefficient, oh 0 is the fundamental frequency, K rh is the resonant gain, oh ch is the resonant angular frequency, and h is the harmonic order.

[0032] S2, suppresses input current harmonics through multiple proportional-integral quasi-resonant controller transfer functions; The calculation formula is: y(s) = G(s)*U(s); Wherein, U(s) is the input current harmonic signal, G(s) is the discretized transfer function of the multiple proportional-integral quasi-resonant controller, and y(s) is the output signal.

[0033] The present invention is further configured to analyze only the multiple resonant controller for the convenience of analysis. The accuracy of the resonant point of the discretized resonant controller needs to be guaranteed, so the resonant controller is discretized by using a pre-difference bilinear change. The transfer function of the discretized multiple proportional-integral quasi-resonant controller is: ; Where Ts is the sampling period of the system; ; ; ; .

[0034] The present invention is further configured to obtain voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, convert the voltage data to a stationary coordinate system, calculate the voltage vector after the A and U phases are open-circuited in the stationary coordinate system, divide the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculate the duty cycle of each sector as follows: S1, obtaining the relationship between the phase voltage of the motor and the inverter switch state after the fault; The calculation formula is: ; S2, by modifying the reduced-order transformation matrix, applying the modified reduced-order matrix T αβ AU , transform the phase voltage to the stationary coordinate system; The calculation formula is: ; S3, calculating the relationship between the voltage vector and the switching function in the stationary coordinate system by using the method of modifying the reduced-order transformation matrix and the mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit fault; The calculation formula is: ; In the formula, S B、 S c、 S v and S w Indicates the switching state of the inverter bridge arm. "1" means the upper bridge arm is turned on and the lower bridge arm is turned off; "0" means the lower bridge arm is turned on and the upper bridge arm is turned off. S B、 S c、 S v and S w Substitute the 16 states of the A and U phases into the distribution of the voltage vector after the A and U phases are open-circuited. The entire plane is divided into 8 sectors according to the distribution of the voltage vector in the stationary coordinate system, and the boundary vector of the sector is selected as v 1. v 2 The general formula for the duty cycle of each sector in the stationary coordinate system is obtained: ; In the formula f 1. f 2 for v 1. v 2 is the angle between the reference vector and the α axis, θ is the angle between the reference vector and the α axis, | v ref | is the modulus of the reference vector, | v 1|、| v2| is the modulus length of each sector boundary vector. D1 and D2 represent the occupation time of non-zero vectors v1 and v2 respectively. They determine the time ratio of the two non-zero vectors being activated in the whole control cycle. D1 represents the occupation time of zero vector. Zero vector refers to the state where all inverter switches are turned off. Its action time is used to transition to the next voltage vector and helps to maintain the balance of DC side voltage. By reasonably arranging the action time of different voltage vectors, any reference voltage vector can be synthesized. These voltage vectors are used to synthesize the required voltage waveform in motor control, thereby controlling the running state of the motor.

[0035] The present invention is further configured that the steps of the method for correcting the reduced-order transformation matrix are: S1, use the zero-sequence flux to correct the fundamental flux, inject the zero-sequence component into the first two rows of the original matrix, and correct the reduced-order Clark matrix; The calculation formula is: ; S2, price reduction processing of Park matrix; The formula is: ; S3, obtain the corrected magnetic flux; The formula is: ; In the formula, P α0 、P α0 It is the projection of the rotor permanent magnet in the stationary coordinate system during normal operation.

[0036] The present invention is further configured that the mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit faults includes a voltage equation and an electromagnetic torque equation under the A and U phase open circuit faults; The voltage equation is: ; The formula of the electromagnetic torque equation is: 10. ; in, is the d-axis component of the stator voltage, is the q-axis component of the stator voltage, is the d-axis component of the stator current, is the q-axis component of the stator current, R is the stator resistance; is the electrical angular velocity; is the d-axis inductance component, is the q-axis inductance component. is the permanent magnet flux of the motor.

[0037] The present invention also discloses a dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control system, including a speed outer loop and a current inner loop; The speed outer loop includes a PI controller to output the reference q Shaft current; The current inner loop includes a multiple proportional integral quasi-resonant controller and a feedforward decoupling control. The internal structure of the current inner loop is composed of Figure 2 It is used to output the reference dq axis voltage signal and send it to the SVPWM control algorithm module under fault conditions to calculate the action time of each vector, such as Figure 4 As shown, the output is finally sent to the motor through the inverter to complete the fault-tolerant control of the open circuit of the A and U phases of the dual three-phase permanent magnet synchronous motor.

[0038] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0039] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0040] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent results or equivalent process changes made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method, characterized in that: The following steps are involved: S1, obtaining voltage and current data of the dual three-phase permanent magnet synchronous motor under A and U phase open circuit fault; S2. Obtaining the components of current harmonics under the A-phase and U-phase open circuit fault according to the voltage and current data, and obtaining harmonic characteristic information through the components of the current harmonics; S3, based on the harmonic characteristic information, suppressing the current harmonics by a multiple proportional-integral quasi-resonant controller; S4, obtaining voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, converting the voltage data to a stationary coordinate system, calculating a voltage vector after the A and U phases are open-circuited in the stationary coordinate system, dividing the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculating a duty cycle of each sector; S5. Generate a PWM signal according to the duty cycle of each sector to control the inverter to output a new voltage vector, and control the operation of the motor according to the new voltage vector.

2. The open-circuit fault-tolerant control method for phases A and U of a dual three-phase permanent magnet synchronous motor according to claim 1, characterized in that: The components of the current harmonics include terminal voltage harmonics and back electromotive force harmonics introduced by the motor body structure; The terminal voltage harmonics are quantitatively calculated through terminal voltage distortion, and the formula is: ； In the formula, ∆ u n For the n Phase terminal voltage distortion, ∆ u n(1） For the n Phase fundamental voltage distortion, No. n The initial phase of the fundamental current, ∆ u d The voltage distortion coefficient caused by the nonlinearity of the inverter, k is the harmonic order, is the angular velocity, t is the time; The quantitative calculation formula of the back electromotive force harmonics is: ； In the formula, e n For the n The reverse potential of the phase, O + is the set of all positive odd numbers, The fundamental magnetomotive force k The amplitude of the subharmonic back EMF, For the n The initial phase of the fundamental current, where the first phase is the harmonic back electromotive force generated by the fundamental magnetomotive force, , They are ν Positive and negative sequence generation of subharmonic magnetomotive force k The amplitude of the subharmonic back EMF, , They are k Positive and negative sequence generation of subharmonic magnetomotive force k The first phase of the subharmonic back EMF, the second and third phases are the positive and negative sequence harmonic back EMF generated by the harmonic magnetomotive force.

3. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 2, characterized in that: The step of obtaining harmonic characteristic information through the components of the current harmonics is: S1, transform the harmonic current into the dq coordinate system by modifying the reduced-order transformation matrix and removing the elements related to the zero-sequence component in the matrix; S2, obtain the harmonic current dq Coordinate system mapping; S3, through the harmonic current in dq The coordinate system is mapped to obtain the harmonic order.

4. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 3, characterized in that: The step of suppressing the current harmonics by using a multiple proportional-integral quasi-resonant controller is as follows: S1, bringing the harmonic order into the transfer function of the multiple proportional integral quasi-resonant controller; The transfer function of the multiple proportional-integral quasi-resonant controller is: ； In the formula, K p is the proportional coefficient of the PI controller, K i is the integration coefficient, ω 0 is the fundamental frequency, K rh is the resonant gain, ω ch is the resonant angular frequency, h is the harmonic order; S2, suppressing the input current harmonics by using the multiple proportional-integral quasi-resonant controller transfer function; The calculation formula is: y(s) = G(s)*U(s); Among them, U(s) is the input current harmonic signal, G(s) is the discretized transfer function of the multiple proportional-integral quasi-resonant controller, and y(s) is the output signal.

5. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 4, characterized in that: The transfer function of the multiple proportional-integral quasi-resonant controller is: ； In the formula, K p is the proportional coefficient of the PI controller, K i is the integration coefficient, ω 0 is the fundamental frequency, K rh is the resonant gain, ω ch is the resonant angular frequency, and h is the harmonic order.

6. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 5, characterized in that: The discretized multiple proportional-integral quasi-resonant controller transfer function is: ； Where Ts is the sampling period of the system; ； ； ； 。 7. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 6, characterized in that: The step of obtaining the voltage data after the current harmonics are suppressed by the multiple proportional integral quasi-resonant controller, converting the voltage data to a stationary coordinate system, calculating the voltage vector after the A and U phases are open-circuited in the stationary coordinate system, dividing the distribution of the voltage vector in the stationary coordinate system into 8 sectors, and calculating the duty cycle of each sector is as follows: S1, obtaining the relationship between the phase voltage of the motor and the inverter switch state after the fault; The calculation formula is: ； S2, by modifying the reduced-order transformation matrix, applying the modified reduced-order matrix T αβ AU , transform the phase voltage to the stationary coordinate system; The calculation formula is: ； S3, calculating the relationship between the voltage vector and the switching function in the stationary coordinate system by using the method of modifying the reduced-order transformation matrix and the mathematical model of the permanent magnet synchronous motor under the A and U phase open circuit fault; The calculation formula is: ； In the formula, S B、 S c、 S v and S w Indicates the switching state of the inverter bridge arm, "1" means the upper bridge arm is turned on and the lower bridge arm is turned off; "0" means the lower bridge arm is turned on and the upper bridge arm is turned off; S B、 S c、 S v and S w Substitute the 16 states of the A and U phases into the distribution of the voltage vector after the A and U phases are open-circuited. The entire plane is divided into 8 sectors according to the distribution of the voltage vector in the stationary coordinate system, and the boundary vector of the sector is selected as v 1. v 2 The general formula for the duty cycle of each sector in the stationary coordinate system is obtained: ； In the formula φ 1. φ 2 for v 1. v 2 is the angle between the reference vector and the α axis, θ is the angle between the reference vector and the α axis, | v ref | is the modulus of the reference vector, | v 1|、| v 2| is the modulus of each sector boundary vector, D1 and D2 represent the occupation time of non-zero vectors v1 and v2 respectively, and D0 represents the occupation time of the zero vector.

8. The open-circuit fault-tolerant control method for phases A and U of a dual three-phase permanent magnet synchronous motor according to claim 7, characterized in that: The steps of the method for correcting the reduced-order transformation matrix are: S1, use the zero-sequence flux to correct the fundamental flux, inject the zero-sequence component into the first two rows of the original matrix, and correct the reduced-order Clark matrix; The calculation formula is: ； S2, reduce the Park matrix; The formula is: ； S3, obtain the corrected magnetic flux; The formula is: ； In the formula, Ψ α0 ,Ψ α0 It is the projection of the rotor permanent magnet in the stationary coordinate system during normal operation.

9. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control method according to claim 8, wherein the mathematical model of the permanent magnet synchronous motor under the A, U phase open circuit fault includes a voltage equation and an electromagnetic torque equation under the A, U phase open circuit fault; The voltage equation is: ； The formula of the electromagnetic torque equation is: ； in, is the d-axis component of the stator voltage, is the q-axis component of the stator voltage, is the d-axis component of the stator current, is the q-axis component of the stator current, R is the stator resistance; is the electrical angular velocity; is the d-axis inductance component, is the q-axis inductance component. is the permanent magnet flux of the motor.

10. A dual three-phase permanent magnet synchronous motor A, U phase open circuit fault-tolerant control system, characterized in that: Including speed outer loop and current inner loop; The speed outer loop includes a PI controller for outputting a reference q Shaft current; The current inner loop includes a multiple proportional-integral quasi-resonant controller and a feedforward decoupling control, which are used to output a reference dq-axis voltage signal, and send it to the SVPWM control algorithm module under fault conditions to calculate the action time of each vector, and finally output it to the motor through the inverter to complete the fault-tolerant control of the open circuit A and U phases of the dual three-phase permanent magnet synchronous motor.

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