A deep fault-tolerant method based on open-winding motor driver

Abstract

This application discloses a deep fault-tolerant method based on an open-winding motor driver, comprising: obtaining a reference voltage vector; redistributing the reference voltage vector based on a preset modulation weight to obtain a modulation reference voltage vector; performing coordinate transformation on the modulation reference voltage vector to obtain α-axis and β-axis components; obtaining the fault state based on the number of faulty bridge arms; determining the fault type from the fault state based on the faulty bridge arm; if the fault type is the first fault type, judging the sector of the three-phase inverter where the faulty bridge arm is located using the α-axis and β-axis components; subsequently obtaining preset variables using the α-axis and β-axis components; judging the sector of another three-phase inverter using the preset variables; if the fault type is the second or third fault type, judging the sector of both three-phase inverters using the α-axis and β-axis components. This application enables the system to maintain reliability and availability when facing different fault conditions.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a deep fault-tolerant method based on an open-winding motor driver. Background Technology

[0002] Under complex operating conditions, open-winding permanent magnet synchronous motor drive systems are prone to two main types of faults: electrical faults and mechanical faults. Electrical faults are mainly concentrated in the power conversion of the electric drive system. As the core drive unit, the inverter is in a high-frequency switching state during operation, resulting in a significantly higher probability of fault occurrence than the motor itself. Therefore, it is of great significance to study the fault-tolerant control of the electric drive system under inverter switching device failures.

[0003] The fault-tolerant control strategies for isolated DC bus type open-winding motor drive systems mainly include short-circuit reconfiguration, symmetrical reconfiguration, and residual vector reconfiguration. Short-circuit reconfiguration short-circuits the windings by faulty inverter lower bridge arm, degrading the dual-inverter drive to a single-inverter mode. Its modulation strategy uses traditional SVPWM, simplifying the reference voltage vector from V1-V2 to V1. However, this method discards a large number of non-faulty power devices, significantly reducing the system's voltage output capability, leaving room for optimization. Symmetrical reconfiguration sets the lower bridge arms of phase A of both inverter 1 and inverter 2 to normally open simultaneously when inverter 1's phase A bridge arm fails, achieving a symmetrical reconfiguration with phase A short-circuited to ground. Residual reconfiguration only isolates the faulty switch. Although this increases the number of voltage vectors, its maximum output voltage remains 50% of the pre-fault level while maintaining system linear modulation. Existing strategies require further optimization in balancing fault tolerance and voltage output capability. Summary of the Invention

[0004] The purpose of this application is to provide a deep fault-tolerant method based on an open-winding motor driver, in order to solve the technical problem that existing systems are difficult to handle various fault conditions. The numerous technical effects of the preferred solutions among the many technical solutions provided in this application are detailed below.

[0005] To achieve the above objectives, this application provides the following technical solutions: The first aspect of this application provides a deep fault-tolerant method based on an open-winding motor driver. This method is applied to a deep fault-tolerant drive system for an open-winding permanent magnet synchronous motor, which includes two three-phase inverters. The deep fault-tolerant method includes: acquiring a reference voltage vector; redistributing the reference voltage vector based on a preset modulation weight to obtain a modulation reference voltage vector; performing a coordinate transformation on the modulation reference voltage vector to obtain an α-axis component and a β-axis component; acquiring a fault state based on the number of faulty bridge arms; determining a fault type from the fault states based on the faulty bridge arms; if the fault type is a first fault type, adjusting the faulty bridge arm using the α-axis component and the β-axis component. The sector of the three-phase inverter where the arm is located is determined, and then a preset variable is obtained through the α-axis component and the β-axis component. The sector of another three-phase inverter is determined through the preset variable. If the fault type is the second fault type or the third fault type, both three-phase inverters determine the sector through the α-axis component and the β-axis component. Based on the modulation reference voltage vector, sector number and switching cycle, the action time of each voltage vector in different three-phase inverters is calculated, and the duty cycle of each is calculated according to the action time. The duty cycle is compared with the triangular carrier to obtain the PWM pulse signal. The PWM pulse signal is used to control the switching transistors corresponding to each bridge arm to obtain the target voltage.

[0006] In some embodiments, if the fault type is the fourth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, turning on the upper transistor of the non-faulty bridge arm and closing the lower transistor of the non-faulty bridge arm; when the triangular carrier wave is less than 0.5, closing the upper transistor of the non-faulty bridge arm and turning on the lower transistor of the non-faulty bridge arm; and judging the sector of another three-phase inverter by the preset variable.

[0007] In some embodiments, when the fault type is the fifth fault type or the sixth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the two-phase faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, turning on the upper switch of the non-faulty bridge arm and closing the lower switch of the non-faulty bridge arm; when the triangular carrier wave is less than 0.5, closing the upper switch of the non-faulty bridge arm and turning on the lower switch of the non-faulty bridge arm; and judging the sector of another three-phase inverter by using the α-axis component and the β-axis component.

[0008] In some embodiments, when the fault type is the seventh fault type, the deep fault-tolerant method based on the open-winding motor driver includes: judging the sectors of the non-faulty three-phase inverter through the preset variable.

[0009] In some embodiments, when the fault type is the eighth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: judging the sector of the single-phase faulted three-phase inverter by the α-axis component and the β-axis component.

[0010] In some embodiments, the modulation reference voltage vector is calculated using the following formula: Where α is a preset modulation weight set based on the maximum modulated radius.

[0011] In some embodiments, when the fault type is the first fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located is one-third; when the fault type is the second fault type or the third fault type, the preset modulation weight is one-half; when the fault type is the fourth fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located is 0.

[0012] In some embodiments, obtaining the reference voltage vector includes: Obtain the rotor position angle; Obtain the current of a three-phase open-winding motor in a stationary coordinate system, perform coordinate transformation on the three-phase open-winding motor current, compare the coordinate-transformed current with the reference current, and obtain the error current. The reference voltage is calculated using the error current. The reference voltage vector in the stationary coordinate system is obtained using the reference voltage and the rotor position angle. Then, the reference voltage vector in the stationary coordinate system is transformed to obtain the reference voltage vector in the rotating coordinate system.

[0013] In some embodiments, the maximum modulated interval radius of the first fault type is The maximum modulated range radius of the second fault type, the third fault type, the fourth fault type, and the seventh fault type is all The maximum modulated interval radius of the fifth fault type, the sixth fault type, and the eighth fault type is all V dc It is a DC power supply.

[0014] A second aspect of this application provides a deep fault-tolerant drive system for an open-winding permanent magnet synchronous motor. This system utilizes the deep fault-tolerant method based on an open-winding motor driver as described above, and includes two DC power supplies, two DC bus capacitor banks, two three-phase inverters, and two bidirectional thyristor banks. The DC power supplies, DC bus capacitor banks, three-phase inverters, and bidirectional thyristor banks are symmetrically arranged on both sides of the open-winding permanent magnet synchronous motor. Each three-phase inverter includes three bridge arms, and each bridge arm includes two switching transistors and two fast-blow fuses, one end of which is connected to the positive terminal of the DC power supply. One end is connected to one end of a switch, the other end of which is connected to one end of another switch, the other end of which is connected to one end of another fast-acting fuse, and the other end of the fast-acting fuse is connected to the negative terminal of the DC power supply; the DC bus capacitor bank is connected in parallel with the bridge arm across the two ends of the DC power supply; the bidirectional thyristor bank includes six bidirectional thyristors corresponding to the bridge arm; the midpoint of each bridge arm is connected to a corresponding terminal of the open-winding permanent magnet synchronous motor and one end of the bidirectional thyristor; the other end of the bidirectional thyristor is connected to the midpoint of the DC bus capacitor bank.

[0015] Implementing one of the technical solutions described above in this application has the following advantages or beneficial effects: In this application, the sector judgment conditions under different fault conditions are obtained by acquiring the fault state and fault type, that is, by... α Axial components, β The system uses axis components or preset variables to determine the sector, and then generates PWM pulse signals for each switching transistor based on the determination results. In this case, by classifying fault states and fault types and setting corresponding strategies for each fault type, the system can maintain its reliability and availability when facing different fault conditions, while providing timely and flexible fault handling methods. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a flowchart illustrating the deep fault-tolerant method based on an open-winding motor driver according to an embodiment of this application. Figure 2This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current under the first fault type of this application embodiment; Figure 3 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current under the second fault type of this application embodiment; Figure 4 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current under the third and fourth fault types in the embodiments of this application; Figure 5 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq axis current under the fifth fault type of this application embodiment, with loads of 20 N·m and 15 N·m. Figure 6 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq axis current under the sixth fault type of this application embodiment, with loads of 20 N·m and 15 N·m. Figure 7 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current under the seventh fault type of this application embodiment; Figure 8 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current under the eighth fault type in the embodiments of this application; Figure 9 This is a schematic diagram of the simulation results of three-phase current, speed, electromagnetic torque and dq-axis current for fault-tolerant control with dynamic switching of different fault types according to an embodiment of this application. Figure 10 This is a topology diagram of a deeply fault-tolerant drive system for an open-winding permanent magnet synchronous motor according to an embodiment of this application.

[0017] In the diagram: 1. Deep fault-tolerant drive system for open-winding permanent magnet synchronous motor; 10. DC power supply; 20. DC bus capacitor bank; 30. Three-phase inverter; 40. Bidirectional thyristor bank; 2. Open-winding permanent magnet synchronous motor; 31. Bridge arm; 310. Switching transistor; 311. Fast-acting fuse; 41. Bidirectional thyristor. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments and depict various exemplary embodiments that may be adopted to implement this application. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of this application disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of this application.

[0019] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the referred element must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. The term "multiple" means two or more. The terms "connected" and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more of the related listed items. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] To illustrate the technical solutions described in this application, specific embodiments are provided below, showing only the parts related to the embodiments of this application.

[0021] like Figures 1 to 10 As shown, this application provides a deep fault-tolerant method based on an open-winding motor driver, which may include: S1. Obtain the reference voltage vector, redistribute the reference voltage vector based on the preset modulation weights to obtain the modulation reference voltage vector, and perform coordinate transformation on the modulation reference voltage vector to obtain... α Axial components and β Axial components.

[0022] The deep fault-tolerant method of this application embodiment is applied to a deep fault-tolerant drive system for an open-winding permanent magnet synchronous motor. The deep fault-tolerant drive system for an open-winding permanent magnet synchronous motor may include two three-phase inverters, namely a first three-phase inverter and a second three-phase inverter. The first three-phase inverter includes a first bridge arm, a second bridge arm, and a third bridge arm, and the second three-phase inverter includes a fourth bridge arm, a fifth bridge arm, and a sixth bridge arm. Each bridge arm includes a switching transistor and a fast-blow fuse.

[0023] In some embodiments, obtaining the reference voltage vector may include: obtaining the rotor position angle; obtaining the three-phase open-winding motor current in the stationary coordinate system; performing coordinate transformation on the three-phase open-winding motor current; comparing the coordinate-transformed current with the reference current to obtain the error current; calculating the reference voltage using the error current; obtaining the reference voltage vector in the stationary coordinate system using the reference voltage and the rotor position angle; and then performing coordinate transformation on the reference voltage vector in the stationary coordinate system to obtain the reference voltage vector in the rotating coordinate system.

[0024] Specifically, the rotor position angle θ can be obtained by using a position sensor based on the rotational position of the open-winding motor, and then the motor speed n can be calculated by differentiating the rotor position angle θ. The current i of a three-phase open-winding motor in the stationary coordinate system abc is detected by a current sensor. a i b and i c Then use the abc~dq0 module to process i a i b i c Perform a coordinate transformation to obtain i in the rotated coordinate system dq0. d i q and i0; By rotating the d-axis current i in the coordinate system d With q-axis current i q Relative to the d-axis reference current i dref and q-axis reference current i qref By comparing the two, the d-axis error current and the q-axis error current are obtained. The d-axis reference voltage U is obtained by using the d-axis error current and the q-axis error current. d and q-axis reference voltage U q ; Reference voltage U along the d-axis d q-axis reference voltage U q The rotor position angle θ is used to obtain the reference voltage of each phase of the first three-phase inverter and the reference voltage of each phase of the second three-phase inverter in the stationary coordinate system. Use abc~ αβThe module performs coordinate transformation on the reference voltages of each phase of the first three-phase inverter and the reference voltages of each phase of the second three-phase inverter to obtain a rotating coordinate system. αβ Below α Axial components and β Axial components.

[0025] In some embodiments, the modulation reference voltage vector can be calculated using the following formula: Where α is a preset modulation weight determined based on fault mode and modulation capability optimization, and its value range satisfies 0 < α < 1, U ref1 U is the modulation reference voltage vector of the first three-phase inverter. ref2 This is the modulation reference voltage vector of the second and third phase inverters.

[0026] In some embodiments, the preset modulation weights can be expressed by the following formula: Wherein, R3p4s is the maximum modulated radius of the inverter in 3P4S mode, and R3p6s is the maximum modulated radius of the inverter in 3P6S mode.

[0027] S2. Obtain the fault status based on the number of faulty bridge arms, and determine the fault type from the fault status based on the faulty bridge arm. If the fault type is the first fault type, then... α Axial components, β The shaft component determines the sector of the three-phase inverter where the faulty bridge arm is located, and then... α Axial components, β The axis component acquires preset variables, and the sector of another three-phase inverter is judged based on these preset variables. If the fault type is the second or third fault type, both three-phase inverters pass... α Axial components, β The axis component is used to determine the sector.

[0028] Specifically, the fault states can include a first fault state, a second fault state, a third fault state, and a fourth fault state. The first fault state includes a first fault type, the second fault state includes a second, third, and fourth fault types, the third fault state includes a fifth, sixth, and seventh fault types, and the fourth fault state includes an eighth fault type. The fault states can correspond to the number of faulty bridge arms; for example, the number of faulty bridge arms in the first fault state can be 1, and the number of faulty bridge arms in the second fault state can be 2.

[0029] Furthermore, the first fault type can be used to characterize a single-phase fault in a single inverter, such as a first arm fault or a third arm fault, with a fault arm count of 1.

[0030] The second fault type can be used to characterize in-phase faults in different inverters, such as faults in both the first and fourth bridge arms, or faults in both the second and fifth bridge arms. The third fault type can be used to characterize different phase faults in different inverters, such as faults in both the first and fifth bridge arms, or faults in both the first and sixth bridge arms. The fourth fault type can be used to characterize different phase faults in the same inverter, such as faults in both the first and second bridge arms, or faults in both the first and third bridge arms. The number of faulty bridge arms is 2.

[0031] The fifth fault type can be used to characterize in-phase faults in different inverters, such as faults in the first, second, and fourth bridge arms; the sixth fault type can be used to characterize different phase faults in different inverters, such as faults in the first, second, and sixth bridge arms; the seventh fault type can be used to characterize different phase faults in the same inverter, such as faults in the first, second, and third bridge arms. The number of faulty bridge arms is 3.

[0032] The eighth fault type can be used to characterize in-phase faults in different inverters, such as faults in the first, second, third, and fourth bridge arms, with a faulty bridge arm count of 4.

[0033] S3. Based on the modulation reference voltage vector, sector number, and switching cycle, calculate the duration of each voltage vector in different three-phase inverters, then calculate the duty cycle of each vector according to the duration, and compare the duty cycle with the triangular carrier wave to obtain the PWM pulse signal. The PWM pulse signal is used to control the switching transistors corresponding to each bridge arm to obtain the target voltage.

[0034] When the fault type is the first fault type, it can be done through... α Axial components, β The shaft component is used to determine the sector of the three-phase inverter where the faulty bridge arm is located. The following explanation uses the fault of the first three-phase inverter as an example: If the first bridge arm fails, as shown in Table 1, if α The axial components are positive and β If the axis component is positive, the sector number is 1; if α The axial component is negative and β If the axis component is positive, then the sector number is 2; if α The axial component is negative and β If the axis component is negative, the sector number is 3; if α The axial components are positive and β If the axis component is negative, then the sector number is 4.

[0035] Table 1 It should be noted that, since it is an isolated DC bus, if the faulty bridge arm is the fourth bridge arm of the second three-phase inverter, the sector determination conditions can be the same as those for the first bridge arm.

[0036] If the second bridge arm fails, it can αβ The coordinate system is rotated 120° counterclockwise, as shown in Table 2. α The axial components are positive and β If the axis component is positive, the sector number is 1; if α The axial component is negative and β If the axis component is positive, then the sector number is 2; if α The axial component is negative and β If the axis component is negative, the sector number is 3; if α The axial components are positive and β If the axis component is negative, then the sector number is 4.

[0037] Table 2 Similarly, if the faulty bridge arm is the fifth bridge arm of the second three-phase inverter, the sector determination conditions can be the same as those for the second bridge arm.

[0038] If the third bridge arm fails, αβ The coordinate system is rotated 120° clockwise, as shown in Table 3. α The axial components are positive and β If the axis component is positive, the sector number is 1; if α The axial component is negative and β If the axis component is positive, then the sector number is 2; if α The axial component is negative and β If the axis component is negative, the sector number is 3; if α The axial components are positive and β If the axis component is negative, then the sector number is 4.

[0039] Table 3 Similarly, if the faulty bridge arm is the sixth bridge arm of the second three-phase inverter, the sector determination conditions can be the same as those for the third bridge arm mentioned above.

[0040] In some embodiments, the duration of the voltage vector of a three-phase inverter experiencing a single-phase fault can be calculated using the following formula: Where T1 and T2 are the durations of voltage vectors V1 and V2, Ts is the switching period, and T0 is the duration of the equivalent zero voltage vector. V dc This is the DC bus voltage.

[0041] In some embodiments, the duty cycle of a three-phase inverter experiencing a single-phase fault can be calculated using the following formula: in, D b , D c These are the duty cycles of the SVPWM waveforms of the unfaulty bridge arms. If the faulty bridge arm is the first bridge arm, then these are the duty cycles of the second and third bridge arms. Furthermore, if the faulty bridge arm is the fourth bridge arm of the second three-phase inverter, the duty cycle can also be calculated using the above formula. Similarly, if the faulty bridge arm is the second or third bridge arm, the duty cycles of the other two bridge arms in the same phase are calculated using the same formula.

[0042] If the fault type is the first fault type, the other three-phase inverter can be based on α Axial components, β Axis component acquisition preset variables u a 、u b 、u c By pre-setting variables u a 、u b 、u c The sector is determined by the symbolic characteristics.

[0043] In some embodiments, preset variables u a 、u b 、u c It can be calculated using the following formula: As shown in Table 4, if the preset variables u a Positive, preset variable u b Positive and pre-defined variables u c If the value is negative, the sector number is 1; if the preset variable... u a Positive, preset variable u b Negative and pre-defined variables u c If the value is negative, the sector number is 2; if the preset variable... u a Positive, preset variable u b Negative and pre-defined variables uc If positive, the sector number is 3; if the preset variable... u a Negative, pre-defined variable u b Negative and pre-defined variables u c If positive, the sector number is 4; if the preset variable... u a Negative, pre-defined variable u b Positive and pre-defined variables u c If positive, the sector number is 5; if the preset variable... u a Negative, pre-defined variable u b Positive and pre-defined variables u c If the value is negative, the sector number is 6.

[0044] Table 4 In some embodiments, the duration of the voltage vector of the three-phase inverter under normal conditions (i.e., without a faulty bridge arm) can be calculated using the following formula: Where T1, T2, and T3 are the durations of voltage vectors V1, V2, and V3, respectively; Ts is the switching period; and T0 is the duration of the equivalent zero voltage vector. V dc This is the DC bus voltage.

[0045] In some embodiments, the duty cycle of a non-faulty three-phase inverter can be calculated using the following formula: If the fault type is the second or third fault type, meaning each three-phase inverter has a single-phase faulty bridge arm, then it can be resolved by... α Axial components, β The sector is determined by the axis component, that is, the sector is determined according to Table 1, Table 2 and Table 3.

[0046] In some embodiments, if the fault type is the fourth fault type, the deep fault-tolerant method based on the open-winding motor driver may include: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, turning on the upper transistor of the non-faulty bridge arm and closing the lower transistor of the non-faulty bridge arm; when the triangular carrier wave is less than 0.5, turning on the upper transistor of the non-faulty bridge arm and turning on the lower transistor of the non-faulty bridge arm; and judging the sector of another three-phase inverter by using a preset variable.

[0047] For example, if the first and second arms of the first three-phase inverter fail, the duty cycle of the third arm can be set to 0.5. The second three-phase inverter then uses preset variables for sector determination, which can be done using Table 4. This is equivalent to fixing the output potential of the third arm to the midpoint potential of the DC bus capacitor, which is equivalent to virtually connecting the third winding of the first three-phase inverter to the midpoint of the DC bus capacitor to maintain the symmetry of the electric drive system under fault conditions.

[0048] In some embodiments, when the fault type is the fifth or sixth fault type, the deep fault-tolerant method based on the open-winding motor driver may include: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the two-phase faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, turning on the upper transistor of the non-faulty bridge arm and closing the lower transistor of the non-faulty bridge arm; when the triangular carrier wave is less than 0.5, closing the upper transistor of the non-faulty bridge arm and turning on the lower transistor of the non-faulty bridge arm. α Axial components, β The shaft component is used to determine the sector of another three-phase inverter.

[0049] For example, if the first and second arms of the first three-phase inverter fail, and the fourth arm of the second three-phase inverter fails, then the duty cycle of the third arm can be set to 0.5. Meanwhile, the second three-phase inverter can... α Axial components, β The sector is determined by the axis component, which can be done using Table 1.

[0050] In some embodiments, when the fault type is the seventh fault type, the deep fault-tolerant method based on the open-winding motor driver may include: judging the sectors of the non-faulty three-phase inverter by using preset variables. For example, if the first three-phase inverter has a three-phase fault, the sectors of the second three-phase inverter are judged by using preset variables. At this time, the dual-inverter open-winding permanent magnet synchronous motor control is converted into single-inverter star-connected permanent magnet synchronous motor control.

[0051] In some embodiments, when the fault type is the eighth fault type, the deep fault-tolerant method based on the open-winding motor driver may include: through α Axial components, β The shaft component is used to determine the sector of a three-phase inverter with a single-phase fault. For example, if the first three-phase inverter is faulty, this can be determined by... α Axial components, β The shaft component is used to determine the sector of the second and third phase inverters.

[0052] In some embodiments, when the fault type is the first fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located can be one-third; when the fault type is the second or third fault type, the preset modulation weight can be one-half; when the fault type is the fourth fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located can be 0.

[0053] In some embodiments, the maximum modulation interval radius decreases as the number of faulty bridge arms increases. The maximum modulated interval radius for the first fault type can be... The maximum modulated range radius for the second, third, fourth, and seventh fault types can all be [missing information]. The maximum modulated range radius for the fifth, sixth, and eighth fault types can all be [missing information]. V dc It is a DC power supply.

[0054] The following are simulation results of the embodiments of this application under various fault conditions: Under the first fault condition, after the motor starts, the three-phase current waveform can quickly stabilize and maintain the characteristics of a three-phase sine wave. Moreover, after the load increases, the system can quickly adjust the current amplitude to maintain the stability of speed and torque. Specifically, the speed waveform remains stable before and after the load change, without significant fluctuations; the electromagnetic torque waveform can also accurately track the load change, exhibiting good dynamic response characteristics.

[0055] In the second fault state, after the motor starts, the three-phase current waveform can still quickly stabilize and maintain a three-phase sinusoidal characteristic. Furthermore, as the load increases, the system can rapidly adjust the current amplitude to maintain speed and torque stability. Compared to the first fault state, the output capability of the dual inverters further decreases in the second fault state, and its maximum modulated radius decreases from that in the first fault state. Become ,Right now This directly affects the motor's maximum speed and dynamic response performance. Specifically, under the second fault condition, the motor's maximum speed drops significantly, to approximately two-thirds of that under the first fault condition, i.e., from... Reduce to Furthermore, simulation results show that under the second fault condition, the electromagnetic torque waveform can accurately track load changes, exhibiting good dynamic response characteristics. Specifically, the tracking error of the torque waveform remains at a low level, and no obvious hysteresis or overshoot is observed.

[0056] In the third fault state, the output capability of the dual inverters further decreases under the fifth and sixth fault types, and the maximum motor speed can only reach 400 rpm. Simultaneously, when the load shifts from... Increase to Subsequently, the motor phase current exhibited distortion, and the speed and torque also showed unstable jumps. This is because, in a motor drive system, although the inverter's output voltage and output current functionally mainly affect the motor's speed and torque respectively, in actual operation, the two are closely related, and their combined effect plays a crucial role in the system's dynamic performance and stability. Specifically, if the inverter's current output capability is insufficient, for example, limited by the rated current of the power devices or overcurrent protection settings, even if the inverter's output voltage can maintain the speed setpoint, the motor cannot provide enough torque to drive the load, leading to stalling or unstable operation. Subsequently, without changing other simulation conditions, only the load was transferred from... Reduce to Afterwards, the three-phase current, speed and electromagnetic torque of the motor can all reach a stable state, which further illustrates that there is a close relationship between the motor speed and torque; the seventh fault type belongs to the third fault state, but the fault-tolerant control strategy under this fault type is equivalent to reconstructing the isolated DC bus dual inverter OW-PMSM drive system into a single inverter star-connected PMSM drive system. At this time, the maximum speed of the motor should be 800 rpm.

[0057] In the fourth fault condition, the maximum motor speed is the same as in the fifth and sixth fault conditions, only reaching 400 rpm. Simultaneously, when the load changes from... Increase to Subsequently, the motor phase current became distorted, and the speed and torque also exhibited unstable jumps.

[0058] This application also relates to a deep fault-tolerant drive system 1 for an open-winding permanent magnet synchronous motor, which may include two DC power supplies 10, two DC bus capacitor banks 20, two three-phase inverters 30 and two bidirectional thyristor banks 40. The DC power supplies 10, DC bus capacitor banks 20, three-phase inverters 30 and bidirectional thyristor banks 40 are symmetrically arranged on both sides of the open-winding permanent magnet synchronous motor 2.

[0059] Each three-phase inverter 30 includes three bridge arms 31. Each bridge arm 31 includes two switching transistors 310 and two fast-acting fuses 311. One end of one fast-acting fuse 311 is connected to the positive terminal of the DC power supply 10, and the other end is connected to one end of one switching transistor 310. The other end of one switching transistor 310 is connected to one end of another switching transistor 310. The other end of another switching transistor 310 is connected to one end of another fast-acting fuse 311. The other end of the fast-acting fuse 311 is connected to the negative terminal of the DC power supply 10.

[0060] The DC bus capacitor bank 20 and the bridge arm 31 can be connected in parallel across the two ends of the DC power supply 10. The bidirectional thyristor bank 40 includes six bidirectional thyristors 41 corresponding to the bridge arm 31. The midpoint of each bridge arm 31 is connected to a corresponding terminal of the open-winding permanent magnet synchronous motor 2 and one end of the bidirectional thyristor 41. The other end of the bidirectional thyristor 41 can be connected to the midpoint of the DC bus capacitor bank 20.

[0061] Specifically, the open-winding permanent magnet synchronous motor deep fault-tolerant drive system may include a first DC power supply, a second DC power supply, a first DC bus capacitor bank, a second DC bus capacitor bank, a first three-phase inverter, a second three-phase inverter, a first bidirectional thyristor bank, a second bidirectional thyristor bank, and an open-winding permanent magnet synchronous motor.

[0062] In some embodiments, the first three-phase inverter may include a first bridge arm, a second bridge arm, and a third bridge arm. The first bridge arm may include a first switch, a second switch, a first fast-acting fuse, and a second fast-acting fuse. The second bridge arm may include a third switch, a fourth switch, a third fast-acting fuse, and a fourth fast-acting fuse. The third bridge arm may include a fifth switch, a sixth switch, a fifth fast-acting fuse, and a sixth fast-acting fuse. The first bidirectional thyristor group includes three bidirectional thyristors, referred to as the first bidirectional thyristor, the second bidirectional thyristor, and the third bidirectional thyristor, respectively.

[0063] In some embodiments, the second three-phase inverter may include a fourth bridge arm, a fifth bridge arm, and a sixth bridge arm. The fourth bridge arm may include a seventh switch, an eighth switch, a seventh fast-acting fuse, and an eighth fast-acting fuse. The fifth bridge arm may include a ninth switch, a tenth switch, a ninth fast-acting fuse, and a tenth fast-acting fuse. The sixth bridge arm may include an eleventh switch, a twelfth switch, an eleventh fast-acting fuse, and a twelfth fast-acting fuse. The second bidirectional thyristor group includes three bidirectional thyristors, referred to as the fourth bidirectional thyristor, the fifth bidirectional thyristor, and the sixth bidirectional thyristor, respectively.

[0064] In some embodiments, the second end of the first switch can be connected to the first end of the second switch, the second end of the third switch can be connected to the first end of the fourth switch, and the second end of the fifth switch can be connected to the first end of the sixth switch.

[0065] In some embodiments, the second end of the seventh switch can be connected to the first end of the eighth switch, the second end of the ninth switch can be connected to the first end of the tenth switch, and the second end of the eleventh switch can be connected to the first end of the twelfth switch.

[0066] In some embodiments, the first end of the first switching transistor can be connected to the second end of the first fast-acting fuse, the second end of the second switching transistor can be connected to the first end of the second fast-acting fuse, the first end of the third switching transistor can be connected to the second end of the third fast-acting fuse, the second end of the fourth switching transistor can be connected to the first end of the fourth fast-acting fuse, the first end of the fifth switching transistor can be connected to the second end of the fifth fast-acting fuse, and the second end of the sixth switching transistor can be connected to the first end of the sixth fast-acting fuse.

[0067] In some embodiments, the first end of the seventh switch can be connected to the second end of the seventh fast-acting fuse, the second end of the eighth switch can be connected to the first end of the eighth fast-acting fuse, the first end of the ninth switch can be connected to the second end of the ninth fast-acting fuse, the second end of the tenth switch can be connected to the first end of the tenth fast-acting fuse, the first end of the eleventh switch can be connected to the second end of the eleventh fast-acting fuse, and the second end of the twelfth switch can be connected to the first end of the twelfth fast-acting fuse.

[0068] In some embodiments, an open-winding permanent magnet synchronous motor may include three stator windings, referred to as the first stator winding, the second stator winding, and the third stator winding, respectively.

[0069] In some embodiments, the first DC bus capacitor bank may include a first DC bus capacitor and a second DC bus capacitor, wherein the second terminal of the first DC bus capacitor is connected to the first terminal of the second DC bus capacitor.

[0070] In some embodiments, the second DC bus capacitor bank may include a third DC bus capacitor and a fourth DC bus capacitor, with the second terminal of the third DC bus capacitor connected to the first terminal of the fourth DC bus capacitor.

[0071] In some embodiments, the first DC bus capacitor bank, the first bridge arm, the second bridge arm, and the third bridge arm can be connected in parallel across the two ends of the first DC power supply; the midpoint of the first switch and the second switch are connected to the first terminal of the first stator winding, the midpoint of the third switch and the fourth switch are connected to the first terminal of the second stator winding, and the midpoint of the fifth switch and the sixth switch are connected to the first terminal of the third stator winding.

[0072] In some embodiments, the second DC bus capacitor bank, the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm can be connected in parallel across the two ends of the second DC power supply; the midpoints of the seventh and eighth switching transistors are connected to the second terminal of the first stator winding, the midpoints of the ninth and tenth switching transistors are connected to the second terminal of the second stator winding, and the midpoints of the eleventh and twelfth switching transistors are connected to the second terminal of the third stator winding.

[0073] In some embodiments, the midpoint of the first bridge arm can be connected to the first end of the first bidirectional thyristor, the midpoint of the second bridge arm can be connected to the first end of the second bidirectional thyristor, and the midpoint of the third bridge arm can be connected to the first end of the third bidirectional thyristor; the second ends of the first bidirectional thyristor, the second ends of the second bidirectional thyristor, and the second ends of the third bidirectional thyristor are connected to the midpoint of the first DC bus capacitor bank.

[0074] In some embodiments, the midpoint of the fourth bridge arm can be connected to the first end of the fourth bidirectional thyristor, the midpoint of the fifth bridge arm can be connected to the first end of the fifth bidirectional thyristor, and the midpoint of the sixth bridge arm is connected to the first end of the sixth bidirectional thyristor; the second ends of the fourth bidirectional thyristor, the second ends of the fifth bidirectional thyristor, and the second ends of the sixth bidirectional thyristor are connected to the midpoint of the second DC bus capacitor bank.

[0075] In this application, the sector judgment conditions under different fault conditions are obtained by acquiring the fault status and fault type, that is, by... α Axial components, β The system uses axis components or preset variables to determine the sector, and then generates PWM pulse signals for each switching transistor based on the determination results. In this case, by classifying fault states and fault types and setting corresponding strategies for each fault type, the system can maintain its reliability and availability when facing different fault conditions, while providing timely and flexible fault handling methods.

[0076] Those skilled in the art will understand that all or part of the features / steps of the above-described method embodiments can be implemented by methods, data processing systems, or computer programs. These features may be implemented without hardware, entirely in software, or in a combination of hardware and software. The aforementioned computer program may be stored in one or more computer-readable storage media. When the computer program is executed (e.g., by a processor), it performs the steps of the above-described deep fault-tolerant method embodiments based on open-winding motor drivers.

[0077] The aforementioned storage media capable of storing program code include: static hard disks, solid-state hard disks, random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), optical storage devices, magnetic storage devices, flash memory, magnetic disks or optical disks, and / or combinations of the above devices, that is, they can be implemented by any type of volatile or non-volatile storage devices or combinations thereof.

[0078] This application also provides a processing device embodiment, including one or more processors and a memory; wherein the memory is used to store one or more computer programs, and the one or more processors are used to execute the one or more computer programs stored in the memory, so that the processors execute the features / steps of the above-described embodiment of the deep fault-tolerant method based on an open-winding motor driver.

[0079] The above description is merely a preferred embodiment of this application. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this application. Furthermore, under the teachings of this application, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this application. Therefore, this application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this application.

Claims

1. A deep fault-tolerant method based on an open-winding motor driver, the deep fault-tolerant method being applied to a deep fault-tolerant drive system for an open-winding permanent magnet synchronous motor, the open-winding permanent magnet synchronous motor deep fault-tolerant drive system comprising two three-phase inverters, characterized in that, The deep fault-tolerant method includes: Obtain a reference voltage vector, redistribute the reference voltage vector based on a preset modulation weight to obtain a modulation reference voltage vector, and perform a coordinate transformation on the modulation reference voltage vector to obtain... α Axial components and β Axial components; The fault status is obtained based on the number of faulty bridge arms. The fault type is determined from the fault status based on the faulty bridge arm. If the fault type is the first fault type, then... α Axis component, the β The shaft component determines the sector of the three-phase inverter where the faulty bridge arm is located, and then... α Axis component, the β The axis component acquires a preset variable, and the sector of the other three-phase inverter is judged based on the preset variable. If the fault type is the second fault type or the third fault type, both three-phase inverters pass the... α Axis component, the β The axis component is used to determine the sector; Based on the modulation reference voltage vector, sector number, and switching cycle, the duration of each voltage vector in different three-phase inverters is calculated, and the duty cycle of each vector is calculated according to the duration. The duty cycle is compared with the triangular carrier wave to obtain a PWM pulse signal. The PWM pulse signal is used to control the switching transistors corresponding to each bridge arm to obtain the target voltage.

2. The deep fault-tolerant method based on an open-winding motor driver according to claim 1, characterized in that, If the fault type is the fourth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, the upper transistor of the non-faulty bridge arm is turned on and the lower transistor of the non-faulty bridge arm is closed; when the triangular carrier wave is less than 0.5, the upper transistor of the non-faulty bridge arm is closed and the lower transistor of the non-faulty bridge arm is turned on; and judging the sector of another three-phase inverter by the preset variable.

3. The deep fault-tolerant method based on an open-winding motor driver according to claim 2, characterized in that, When the fault type is the fifth or sixth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: setting the duty cycle of the switching signal of the non-faulty bridge arm in the three-phase inverter where the two-phase faulty bridge arm is located to 0.5; when the triangular carrier wave is greater than 0.5, the upper transistor of the non-faulty bridge arm is turned on and the lower transistor of the non-faulty bridge arm is closed; when the triangular carrier wave is less than 0.5, the upper transistor of the non-faulty bridge arm is closed and the lower transistor of the non-faulty bridge arm is turned on, through... α Axial components, β The axial component is used to determine the sector of another three-phase inverter.

4. The deep fault-tolerant method based on an open-winding motor driver according to claim 3, characterized in that, When the fault type is the seventh fault type, the deep fault-tolerant method based on the open-winding motor driver includes: judging the sector of the non-faulty three-phase inverter through the preset variable.

5. The deep fault-tolerant method based on an open-winding motor driver according to claim 4, characterized in that, When the fault type is the eighth fault type, the deep fault-tolerant method based on the open-winding motor driver includes: through the α Axis component, the β The shaft component is used to determine the sector of a three-phase inverter with a single-phase fault.

6. The deep fault-tolerant method based on an open-winding motor driver according to claim 5, characterized in that, The modulation reference voltage vector is calculated using the following formula: Where α is a preset modulation weight set based on the maximum modulated radius.

7. The deep fault-tolerant method based on an open-winding motor driver according to claim 2, characterized in that, When the fault type is the first fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located is one-third; when the fault type is the second fault type or the third fault type, the preset modulation weight is one-half; when the fault type is the fourth fault type, the preset modulation weight of the three-phase inverter where the faulty bridge arm is located is 0.

8. The deep fault-tolerant method based on an open-winding motor driver according to claim 1, characterized in that, The acquisition of the reference voltage vector includes: Obtain the rotor position angle; Obtain the current of a three-phase open-winding motor in a stationary coordinate system, perform coordinate transformation on the three-phase open-winding motor current, compare the current after coordinate transformation with the reference current, and obtain the error current. The reference voltage is calculated using the error current. The reference voltage vector in the stationary coordinate system is obtained using the reference voltage and the rotor position angle. Then, the reference voltage vector in the stationary coordinate system is transformed to obtain the reference voltage vector in the rotating coordinate system.

9. The deep fault-tolerant method based on an open-winding motor driver according to claim 6, characterized in that, The maximum modulated range radius of the first fault type is The maximum modulated range radius of the second fault type, the third fault type, the fourth fault type, and the seventh fault type is all The maximum modulated interval radius of the fifth fault type, the sixth fault type, and the eighth fault type is all V dc It is a DC power supply.

10. A deeply fault-tolerant drive system for an open-winding permanent magnet synchronous motor, wherein the open-winding permanent magnet synchronous motor deeply fault-tolerant drive system utilizes the deep fault-tolerant method based on an open-winding motor driver as described in any one of claims 1 to 9, characterized in that, It includes two DC power supplies, two DC bus capacitor banks, two three-phase inverters, and two bidirectional thyristor banks. The DC power supplies, the DC bus capacitor banks, the three-phase inverters, and the bidirectional thyristor banks are symmetrically arranged on both sides of the open-winding permanent magnet synchronous motor. Each of the three-phase inverters includes three bridge arms, each bridge arm includes two switching transistors and two fast-blow fuses, one end of one fast-blow fuse is connected to the positive terminal of the DC power supply, the other end of one fast-blow fuse is connected to one end of one of the switching transistors, the other end of one switching transistor is connected to one end of another fast-blow fuse, and the other end of the fast-blow fuse is connected to the negative terminal of the DC power supply. The DC bus capacitor bank is connected in parallel with the bridge arm across the two ends of the DC power supply. The bidirectional thyristor bank includes six bidirectional thyristors corresponding to the bridge arm. The midpoint of each bridge arm is connected to a corresponding terminal of the open-winding permanent magnet synchronous motor and one end of the bidirectional thyristor. The other end of the bidirectional thyristor is connected to the midpoint of the DC bus capacitor bank.

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