Fault-tolerant topology for open-circuit fault of series winding motor inverter and control method of fault-tolerant topology

Abstract

The invention belongs to but is not limited to the technical field of alternating current motor and driving control, and discloses a series winding motor inverter open-circuit fault-tolerant topology and a control method thereof, when an inverter bridge arm has an open-circuit fault or the whole bridge arm is cut off due to a short-circuit fault, a corresponding bipolar diode is switched on, so that the fault tolerance of the inverter is realized. The fault-tolerant topology circuit reconstruction of the series winding motor is realized; and then reconstructing a corresponding voltage vector set, and switching a control algorithm of the series winding motor to realize fault-tolerant driving of the series winding motor without default phase. According to the invention, the residual healthy devices and the bus capacitor of the inverter are fully utilized, the open-phase-free operation of the inverter fault can be realized on the premise of not increasing the system cost and the volume, and the loading capacity of the inverter after the fault is improved. The fault-tolerant topology can also cope with fault-tolerant operation in different fault scenes, the fault-tolerant output performance of the series winding motor can be effectively improved, and stable control after fault-tolerant control is achieved through the fault-tolerant SVPWM and CBPWM modulation algorithms.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the field of AC motor and drive control technology, and in particular relates to an open-circuit fault-tolerant topology of a series winding motor inverter. Background Art

[0002] The series winding motor can achieve 100% bus voltage utilization by connecting the motor winding sequence in series, effectively expanding the motor speed operating range. However, when using this topology drive, due to the two bridge arms in the middle of the inverter L 2. L 3 is subjected to greater current stress, making L 2. L 3Compared to the bridge arms on both sides L 1. L 4. More prone to failure. In addition, compared with the traditional star-connected three-phase motor, the series-wound motor uses more inverters, which reduces the overall reliability of the system. According to the survey, in the motor system, the probability of inverter failure is much higher than the failure rate of other components of the drive system. Inverter failures can be divided into open circuit failures and short circuit failures. After a short circuit failure occurs, it can be switched to an open circuit failure according to the protection circuit. When an open circuit failure occurs in the inverter, the motor torque pulsation will increase and the torque output will decrease, resulting in obvious mechanical vibration in the system or even shutdown.

[0003] At present, the fault-tolerant topology of the traditional star-connected three-phase motor has been widely and deeply studied, but the fault-tolerant topology of the series-wound motor and its drive control method are missing. The series-wound motor topology allows each phase of the winding to be independently decoupled, making its own fault-tolerant capability stronger, but a reliable and stable fault-tolerant strategy is essential. This, to a certain extent, limits the further development and promotion of the series-wound motor in practical applications.

[0004] When a phase arm of a series winding motor fails, the phase winding and the inverter bridge arm are directly cut off, and the other two healthy phase windings can continue to operate without stopping. However, this phase-loss operation puts the motor in a derated operation state and cannot operate under heavy load conditions, limiting the performance of the motor. (For example, X. Sun, Z. Liu, A. Li, Z. Wang, D. Jiang and R. Qu, "Self-Adaptive Fault-Tolerant Control of Three-PhaseSeries-End Winding Motor Drive," in IEEE Transactions on Power Electronics, vol. 37, no. 9, pp. 10939-10950, Sept. 2022, doi: 10.1109 / TPEL.2022.3160747. and X. Zhang and C. Xu, "Second-Time Fault-Tolerant Topology and ControlStrategy for the Open-Winding PMSM System Based on Shared Bridge Arm," in IEEE Transactions on Power Electronics, vol. 35, no. 11, pp. 12181-12193, Nov. 2020, doi: 10.1109 / TPEL.2020.2990303.).

[0005] Through the above analysis, the problems and defects of the existing technology are: the fault-tolerant topology of the series winding motor and its fault-tolerant control method are missing. And the existing solution directly isolates the phase winding and the bridge arm after detecting a fault in a phase bridge arm, realizing phase-loss fault-tolerant operation. At this time, the series winding motor is in a derated operation state, and the performance of the series winding motor cannot be fully utilized in the inverter fault state, and it is not suitable for heavy-load operation. Summary of the invention

[0006] In response to the problems existing in the prior art, the present invention provides an open-circuit fault-tolerant topology of a series-winding motor inverter and a control method thereof. By performing online hardware topology reconstruction on the series-winding motor, it is able to achieve phase-free fault-tolerant operation under fault conditions, thereby effectively improving its fault-tolerant performance and fault load-carrying capacity.

[0007] The present invention is implemented in this way: a series winding motor inverter open circuit fault tolerance topology is composed of four inverter bridge arms, namely bridge arm L 1.L 2. L 3. L 4, and four bipolar diodes: TR 1. TR 2. TR 3. TR 4; Two bus capacitors C 1 and C 2. The motor winding includes A Phase winding, B Phase winding, C Phase winding; After the inverter fails, the corresponding winding circuit is reconstructed so that the series winding motor can achieve phase-to-phase fault-tolerant operation when the inverter fails; A The input end of the phase winding and the bridge arm L 1 are connected to each other, the output end and the bridge arm L 2 connections; B The input end of the phase winding and the bridge arm L 2 are connected to each other, the output end and the bridge arm L 3. Interconnection; C The input end of the phase winding and the bridge arm L 3 connections, output end and bridge arm L 4-phase connection; Bipolar diode TR 1. Set the busbar midpoint O Point and bridge arm L 1 phase connected; TR 2. Connect the midpoint of the bus capacitor to O Point and bridge arm L 2 phase connection; TR 3. Connect the midpoint of the bus capacitor to O Point and bridge arm L 3-phase connection; TR 4. Connect the midpoint of the bus capacitor to O Point and bridge arm L 4 phases connected.

[0008] Furthermore, when an open-circuit fault occurs in the inverter bridge arm, the fault-tolerant circuit is reconstructed by controlling the conduction of the bipolar diode to ensure that the motor operates without phase loss.

[0009] Furthermore, when the bridge arm L 1After an open circuit fault occurs, the bipolar diode is turned on TR 1. At this time A Phase winding input terminal and bus neutral point O Connect the dots, maintainA The phase windings continue to operate in a fault-tolerant manner. B , C The phase windings still maintain normal operation.

[0010] Furthermore, when the bridge arm L 2 After an open circuit fault occurs, the bipolar diode is turned on TR 2. At this time B Phase winding input terminal and bus neutral point O Connect the dots, maintain B The phase windings continue to operate in a fault-tolerant manner. A , C The phase windings still maintain normal operation.

[0011] Furthermore, when the bridge arm L 3 After an open circuit fault occurs, the bipolar diode is turned on TR 3. At this time C Phase winding input terminal and bus neutral point O Connect the dots, maintain C The phase windings continue to operate. A. B The phase windings still maintain normal operation.

[0012] Furthermore, when the bridge arm L 4 After an open circuit fault occurs, the bipolar diode is turned on TR 4. At this time C Phase winding output end and bus neutral point O Connect the dots, maintain C The phase windings continue to operate. A , B The phase windings still maintain normal operation.

[0013] Another object of the present invention is to provide a series winding motor inverter open circuit fault tolerant topology control method, comprising: When an open circuit fault is detected in one phase of the inverter bridge arm, the inverter bridge arm fault is located; the winding voltage distribution is reconstructed according to vector space decoupling, and the series winding motor is in fault tolerance mode at this time; Collect current motor speed n , and set the reference motor speed ; The speed deviation control calculation is performed through the speed PI controller, and the result is projected to dqo Plane, get q Axis reference current ; set up d Axis and zero sequence axis reference current and is zero; Collect the current of each phasei A , i B , i C , after Clark transformation, the result is projected to α-β-o Plane, get i α , i β and i 0 ; Will i α , i β 、i 0 After Park transformation, the result is projected to dqo plane, get the current dqo Plane current i d , i q 、i 0 ; The reference current , and and current dqo Flat i d , i q 、i 0 The reference voltage is obtained by the current PI controller , and ; The reference voltage , and Obtained by Anti-Park transformation , 、 ; Will , 、 Input into the modulation module; the modulation module can adopt the space vector pulse width modulation algorithm SVPWM or the carrier comparison pulse width modulation algorithm CBPWM; When the SVPWM modulation algorithm is used, the fault-tolerant voltage vector set is reconstructed according to the inverter open-circuit fault, and then the required reference voltage vector is synthesized according to the SVPWM, and finally the inverter switching sequence is output to drive the series winding motor to operate in a non-lack-phase fault-tolerant manner; When the CBPWM modulation algorithm is used, the duty cycle of each bridge arm can be obtained according to the following steps: , 、 Input into the modulation module; after coordinate change, α-β-o The reference voltage vector of the plane is converted to abc In the coordinate system, the reference value of the three-phase voltage is obtained , , ; Assume the bridge arm L 1 Open circuit fault occurs, A The phase winding input terminal is connected to the midpoint of the bus capacitor O At point , the duty cycle of each bridge arm is: Bridge arm L 1 is isolated and its duty cycle is: ; Since the bus capacitor midpoint O Point and A The input terminal of the phase winding is connected, and its voltage is 0.5× V dc ; Bridge arm L 2Connect A Phase winding output, bridge arm L The duty cycle of 2 is: ; in, for A Reference value of phase voltage; V dc is the DC bus voltage value; Bridge arm L The duty cycle of 3 is: ; in, for B Reference value of phase voltage; Bridge arm L The duty cycle of 4 is: ; in, for C Reference value of phase voltage; Finally, the duty cycle of each bridge arm is output to the inverter to drive the series winding motor to achieve phase-tolerant fault-free operation.

[0014] Another object of the present invention is to provide a computer device, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the open-circuit fault-tolerant topology control method of the series winding motor inverter.

[0015] Another object of the present invention is to provide a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the open-circuit fault-tolerant topology control method of the series winding motor inverter.

[0016] Another object of the present invention is to provide a three-phase series winding motor inverter topology, including the series winding motor inverter open circuit fault tolerant topology.

[0017] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows: First, the open-circuit fault-tolerant topology of the series-winding motor inverter proposed by the present invention can ensure that the motor can operate without phase loss after the series-winding motor inverter fails, and can effectively improve the fault-tolerant output performance of the series-winding motor; The open-circuit fault-tolerant topology of the series-winding motor inverter proposed in the present invention can realize fault-tolerant control under different fault scenarios of multiple bridge arm faults, and the fault-tolerant topology is simple and easy to implement; The fault-tolerant control method proposed in the present invention includes a space vector pulse width modulation algorithm SVPWM and a carrier comparison pulse width modulation algorithm CBPWM, and makes full use of the remaining healthy devices of the inverter and the bus filter capacitor to achieve stable control after fault-tolerant control.

[0018] Second, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects: (1) The technical solution of the present invention fills the technical gap in the industry at home and abroad: At present, the research on fault-tolerant solutions for bridge arm failures of series-winding motors at home and abroad is relatively simple, mainly realizing the phase-loss operation of series-winding motors through algorithm reconstruction after the failure. There is no strategy to study the non-phase-loss operation under the bridge arm failure of the inverter of the series-winding motor.

[0019] The present invention provides a fault-tolerant topology that does not lack phases after a bridge arm fault of a series-winding motor inverter. Without increasing system cost and volume and without using additional devices, the series-winding motor can operate without lacking phases by utilizing two existing capacitors in the series-winding drive system, thereby effectively improving the load-carrying capacity of the series-winding motor in a fault-tolerant state.

[0020] The technical solution of the present invention provides two detailed fault-tolerant control modulation algorithms, namely SVPWM and CBPWM, which realize high-performance operation of the series winding motor in a fault-tolerant state.

[0021] Third, the technical problems of the prior art solved by the technical solution of the present invention in industrial applications and the significant technical progress achieved; 1. Significant technological progress: Improved load-carrying capacity of the series-winding motor under fault conditions: The fault-tolerant topology provided by the present invention ensures that the series-winding motor can operate without phase loss and does not reduce the load-carrying performance of the series-winding motor.

[0022] No additional increase in system hardware cost and volume: Fault-tolerant operation is achieved by utilizing the two existing bus capacitors of the series-winding motor drive system. No additional hardware circuits are added, and the system cost is not increased, which has certain commercial application prospects.

[0023] Enhanced system robustness: The fault-tolerant topology proposed by the present invention is in a redundant state when the series-wound motor is not faulty, and will not affect the performance of the series-wound motor. When a fault occurs, the fault-tolerant topology is activated, which increases the reliability and robustness of the system.

[0024] 2. The significance of technology promotion: The present invention provides a phase-free fault-tolerant topology and control method under an open-circuit fault of a series-winding motor inverter bridge arm, and also provides a new idea for the application and design of a high-reliability motor drive system. By improving the load capacity under the fault-tolerant state, it provides strong technical support for the intelligent manufacturing and green energy industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the driving topology structure of the three-phase series winding motor in a healthy state provided by an embodiment of the present invention; Figure 2 The open-circuit fault-tolerant drive topology of a three-phase series winding motor inverter provided by an embodiment of the present invention; Figure 3 The fault-tolerant topology provided by the embodiment of the present invention is in the bridge arm L 1. Fault-tolerant topology in case of failure; Figure 4 The fault-tolerant topology provided by the embodiment of the present invention is in the bridge arm L 2. Fault-tolerant topology in case of failure; Figure 5 is a voltage vector distribution diagram of a three-phase series winding motor in a healthy state provided by an embodiment of the present invention; Figure 6 The three-phase series winding motor bridge arm provided by the embodiment of the present invention L 1 Voltage vector distribution diagram after an open circuit fault occurs; Figure 7 The three-phase series winding motor bridge arm provided by the embodiment of the present invention L 1 Fault-tolerant control block diagram after an open circuit fault occurs; Figure 8 It is a three-phase series winding motor bridge arm open circuit fault tolerance control flow chart provided by an embodiment of the present invention;

[0026] Fig. 9 The three-phase series winding motor bridge arm provided by the embodiment of the present invention L 1 Speed ​​and torque waveform after an open circuit fault occurs; Fig.10 The three-phase series winding motor bridge arm provided by the embodiment of the present invention L 1 Current waveform after an open circuit fault occurs; Fig.11 The three-phase series winding motor bridge arm provided by the embodiment of the present invention L 1 Duty cycle waveform of each bridge arm after open circuit fault. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Figure 1 Shown is the drive topology for a healthy series-wound motor.

[0028] like Figure 2 As shown, an embodiment of the present invention provides a series winding motor inverter open circuit fault tolerant topology, which reconstructs the corresponding winding drive circuit after the inverter fails, so that the series winding motor can achieve phase-free fault-tolerant operation when the inverter fails; wherein, A The input end of the phase winding and the bridge arm L 1 are connected to each other, the output end and the bridge arm L 2 connections; B The input end of the phase winding and the bridge arm L 2 are connected to each other, the output end and the bridge arm L 3. Interconnection; C The input end of the phase winding and the bridge arm L 3 connections, output end and bridge arm L 4-phase connection; Bipolar diode TR 1. Set the busbar midpoint O Point and bridge arm L 1Connection; TR 2. Set the busbar midpoint O Point and bridge arm L2 connections; TR 3. Set the busbar midpoint O Point and bridge arm L 3 connections; TR 4. Set the busbar midpoint O Point and bridge arm L 4 connections; When an open-circuit fault occurs in the inverter bridge arm, the fault-tolerant circuit is reconstructed by controlling the conduction of the bipolar diode to ensure that the motor runs without phase loss.

[0029] When the bridge arm L 1After an open circuit fault occurs, the bipolar diode is turned on TR 1. At this time A Phase winding input terminal and bus neutral point O Connect the dots, maintain A The phase windings continue to operate in a fault-tolerant manner. B , C The phase winding still maintains normal operation. At this time, the fault-tolerant topology of the series winding motor is as follows Figure 3 shown.

[0030] When the bridge arm L 2 After an open circuit fault occurs, the bipolar diode is turned on TR 2. At this time B Phase winding input terminal and bus neutral point O Connect the dots, maintain B The phase windings continue to operate in a fault-tolerant manner. A , C The phase winding still maintains normal operation. At this time, the fault-tolerant topology of the series winding motor is as follows Figure 4 shown.

[0031] When the bridge arm L 3 After an open circuit fault occurs, the bipolar diode is turned on TR 3. At this time C Phase winding input terminal and bus neutral point O Connect the dots, maintain C The phase windings continue to operate. A. B The phase windings still maintain normal operation.

[0032] When the bridge arm L 4 After an open circuit fault occurs, the bipolar diode is turned on TR 4. At this time C Phase winding output end and bus neutral point O Connect, maintain C The phase windings continue to operate. A , B The phase windings still maintain normal operation.

[0033] The fault-tolerant topology structure of the present invention realizes the reconstruction of the winding drive circuit when an open circuit fault occurs in the inverter by adding bipolar diodes (TR1, TR2, TR3, TR4) in the inverter bridge arm and a specific motor winding connection method, thereby ensuring that the motor runs without missing phases and avoiding system shutdown. In this topology, the input and output ends of the A, B, and C phase windings are respectively connected to the motor windings through the inverter bridge arm, and the bipolar diode is responsible for connecting the bus midpoint O and the bridge arm to provide a fault-tolerant path.

[0034] When an open-circuit fault occurs in the inverter bridge arm L1, the input end of the A-phase winding is connected to the neutral point O of the busbar by turning on the bipolar diode TR1. In this way, the A-phase winding can still obtain current from the busbar and maintain its operating state without being affected by the inverter bridge arm fault. At this time, the B-phase and C-phase windings maintain normal operation. Through this reconstruction, the A-phase winding can continue to operate in a fault-tolerant manner to ensure that the motor is not missing a phase when a single-phase open-circuit fault occurs. The topological structure at this time allows the A-phase winding to continue to play a role in the inverter system. Figure 3 The circuit topology at this time is shown.

[0035] When an open-circuit fault occurs in the inverter bridge arm L2, the input end of the B-phase winding is connected to the bus neutral point O by turning on the bipolar diode TR2. At this time, the B-phase winding can continue to obtain current from the bus and keep running, while the A-phase and C-phase windings continue to operate normally. The reconstructed circuit ensures that the B-phase winding continues to play a role, ensuring the normal operation of the system without phase loss. Figure 4 The circuit topology at this time is shown, which shows how the system can tolerate faults when the B-phase winding fails.

[0036] When an open-circuit fault occurs in the inverter bridge arm L3, the input end of the C-phase winding is connected to the neutral point O of the busbar by turning on the bipolar diode TR3. This method ensures that the C-phase winding continues to operate, while the A-phase and B-phase windings can still maintain normal operation. At this time, the C-phase winding can still obtain current from the midpoint of the busbar to achieve fault-tolerant operation. This fault-tolerant topology ensures that even if an open-circuit fault occurs in the C-phase bridge arm, the system can still maintain normal operation without phase loss.

[0037] When an open circuit fault occurs in the inverter bridge arm L4, the output end of the C phase winding is connected to the bus neutral point O by turning on the bipolar diode TR4. At this time, the output end of the C phase winding can remain connected to the neutral point O, continue to supply power and work, and ensure that the C phase winding continues to operate normally. The A phase and B phase windings maintain their normal operating state. This reconstruction method effectively avoids the failure of the C phase winding due to the bridge arm L4 fault and ensures the fault tolerance of the system.

[0038] The three-phase series winding motor inverter fault-tolerant topology scheme of the present invention ensures that the motor system can still maintain a phase-free operation state when an open-circuit fault occurs in any single-phase bridge arm by intelligently reconstructing the winding drive circuit. This fault-tolerant topology method not only improves the stability and reliability of the system, but also reduces the downtime caused by inverter failure, significantly improving the fault tolerance and work efficiency of the system. Through this design, the series winding motor system can self-repair in the event of a fault, ensuring the continuous and stable operation of the motor.

[0039] like Figure 8 As shown, based on the above fault-tolerant topology structure, an embodiment of the present invention provides a fault-tolerant control method for a three-phase series winding motor inverter, comprising: First, determine whether the inverter is faulty; if an open circuit fault occurs, locate the faulty inverter serial number, turn on the corresponding bipolar diode, and input the corresponding voltage vector set into the control box program; When the inverter is fault-free, the four bipolar diodes do not operate and the series winding motor is in normal operation mode; by using the modulation algorithm SVPWM or CBPWM, and synthesizing the reference voltage vector according to the voltage vector. The series winding motor voltage vector in a healthy state is as follows Figure 5 As shown; Collect current motor speed n , and set the reference motor speed n* ; The speed deviation control calculation is performed through the speed PI controller, and the result is projected to dqo plane, get the reference current i q * ; Setting the reference current i d * and i 0 * is zero; Collect the current of each phase i A , i B , i C , after Clark transformation, the result is projected to α-β-o Plane, get i α , i β and i 0 ; Will i α , i β 、i0 After Park transformation, the result is projected to dqo plane, get the current dqo Plane current i d , i q 、i 0 ; The reference current i q * , i d * and i 0 * and current dqo Flat i d , i q 、i 0 The reference voltage is obtained by the current PI controller u q * , u d * and u 0 * ; Set the reference voltage u q * , u d * and u 0 * Obtained by Anti-Park transformation u α * , u β *、u 0 * ; Will u α * , u β *、u 0 * Input into the three-dimensional SVPWM modulation module to synthesize the required reference voltage vector, and then output the inverter switching sequence to drive the motor to run; When the CBPWM modulation algorithm is used, the duty cycle of each bridge arm can be obtained according to the following steps. uα * , u β *、 u 0 * Input into the modulation module. After the coordinate change α-β-o The reference voltage vector of the plane is converted to abc In the coordinate system, the reference value of the three-phase voltage is obtained u a * , u b * , u c * The duty cycle of each bridge arm is: Bridge arm L 1The duty cycle is: (1); Since the bus capacitor midpoint O Point and A The input terminal of the phase winding is connected, and its voltage is 0.5× V dc . Bridge arm L 2Connect A Phase winding output, bridge arm L The duty cycle of 2 is: (2); in, u a * for A Reference value of phase voltage; V dc is the DC bus voltage value.

[0040] Bridge arm L The duty cycle of 3 is: (3); in, u b * for B Reference value of phase voltage; Bridge arm L The duty cycle of 4 is: (4); in, u c * for C Reference value of phase voltage; The common mode voltage is injected into the duty cycle of the four bridge arms respectively: (5); The duty cycles of the four bridge arms are: (6); Finally, the duty cycle of each bridge arm is output to the inverter to drive the series winding motor to achieve smooth operation in a healthy state.

[0041] When an open-circuit fault occurs in the inverter, the corresponding bipolar diode is turned on and the series winding motor is in a fault-tolerant operation mode; Bridge Arm L 1 Take an open circuit fault as an example. When the inverter bridge arm is detected L 1 When an open circuit fault occurs; reconstruct the winding voltage distribution according to vector space decoupling, such as Figure 6 As shown; Collect current motor speed n , and set the reference motor speed n* ; The speed deviation control calculation is performed through the speed PI controller, and the result is projected to dqo Plane, get q Axis reference current i q * ; set up d Axis and zero sequence axis reference current i d * and i 0 * is zero; Collect the current phase current of each phase winding i A , i B , i C , after Clark transformation, the result is projected to α-β-o plane, get the actual current of each axis i α , i β and i 0 ; Will i α , i β 、i 0 After Park transformation, the result is projected to dqo plane, get the current dqo Plane current i d ,i q 、i 0 ; The reference current i q * , i d * and i 0 * and current dqo Flat i d , i q 、i 0 The reference voltage is obtained by the current loop PI controller u q * , u d * and u 0 * ; The reference voltage u q * , u d * and u 0 * Obtained by Anti-Park transformation u α * , u β *、u 0 * ; Will u α * , u β *、u 0 * Input to the modulation module. The modulation module can use the space vector pulse width modulation algorithm SVPWM or the carrier comparison pulse width modulation algorithm CBPWM. When the SVPWM modulation algorithm is used, the fault-tolerant voltage vector set is obtained according to the inverter open circuit fault reconstruction. Figure 6 The voltage vector diagram shown is used to synthesize the required reference voltage.

[0042] When the CBPWM modulation algorithm is used, the duty cycle of each bridge arm can be obtained according to the following steps. uα * , u β *、 u 0 * Input into the modulation module. After the coordinate change α-β-o The reference voltage vector of the plane is converted to abc In the coordinate system, the reference value of the three-phase voltage is obtained u a * , u b * , u c * Assuming the bridge arm L 1 Open circuit fault occurs, A The phase winding input terminal is connected to the midpoint of the bus capacitor O At point , the duty cycle of each bridge arm is: Bridge arm L 1 is isolated and its duty cycle is: (7); Since the bus capacitor midpoint O Point and A The input terminal of the phase winding is connected, and its voltage is 0.5× V dc . Bridge arm L 2Connect A Phase winding output, bridge arm L The duty cycle of 2 is: (8); in, u a * for A Reference value of phase voltage; V dc is the DC bus voltage value.

[0043] Bridge arm L The duty cycle of 3 is: (9); in, u b * for B Reference value of phase voltage; Bridge arm L The duty cycle of 4 is: (10); in, u c* for C Reference value of phase voltage; Finally, the duty cycle of each bridge arm is output to the inverter to drive the series winding motor to achieve phase-free fault-tolerant operation. Figure 7 shown.

[0044] Industrial Application Example 1: Efficient Control of Electric Vehicle Drive Motor The driving motor of an electric vehicle needs to provide high efficiency and precise power output under high speed and heavy load conditions. However, the traditional star connection can only utilize 57.7% of the bus voltage utilization, which limits the speed operating range of the motor. The series-wound motor proposed in the present invention can utilize 100% of the bus voltage utilization. Compared with the traditional star-connected topology, it has a wider speed operating range. Considering that the series-wound motor uses the method of connecting the windings in series from head to tail to improve the DC bus voltage utilization, the current stress of the two middle bridge arms is much greater than the current stress of the bridge arms on both sides, which increases the probability of system component failure and reduces the reliability of the series-wound motor.

[0045] The fault-tolerant topology of the present invention does not work in a normal state, and switches to the fault-tolerant topology only when the system detects a fault, thereby effectively improving the reliability of the series winding motor and ensuring that the load capacity remains unchanged after a fault.

[0046] When a phase arm fault is detected, the corresponding bipolar diode is quickly turned on to switch the series winding motor to a fault-tolerant topology state. Then, the corresponding modulation algorithm is switched, and the modulation algorithm can use SVPWM or CBPWM.

[0047] The reliability of the drive motor is improved.

[0048] In the event of a series-wound motor fault, the series-wound motor can operate without missing phases, and in the event of a fault, the load capacity can be kept consistent with that before the fault.

[0049] Industrial Application Example 2: Precision Control of Industrial Robot Joint Motors The joint motors of industrial robots need to achieve high-precision angle control and stable and efficient power output under complex and frequently changing working conditions. However, under the conventional star connection mode, the available amplitude of the motor's phase voltage is relatively limited, which to a certain extent limits the joint motor's ability to accurately control subtle movements and the maximum torque output range that can be achieved. The series winding motor proposed in the present invention can achieve a higher phase voltage utilization rate, and has a better torque output range and angle control accuracy than the conventional star connection topology.

[0050] However, considering that the windings of the series-wound motor are connected in series, although the utilization rate of the phase voltage is improved, the current distribution of each inverter bridge arm is uneven, and the bridge arm current overload is prone to occur. This greatly increases the risk of damage to the internal circuits and related electronic components of the motor, and reduces the overall reliability of the operation of the parallel-wound motor.

[0051] By adopting the fault-tolerant switching topology of the present invention, the fault-tolerant topology is in standby state when the motor is operating normally and does not participate in the operation regulation of the motor. Only when the system detects a fault, it immediately switches to the topology, thereby effectively enhancing the reliability of the series-winding motor and ensuring that the torque output capacity of the motor is maintained at the original level after a fault occurs, thereby ensuring that the robot joint movement is not affected.

[0052] When a branch circuit is detected to have a current overload or line break, the corresponding bipolar diode is immediately triggered to switch the series winding motor to a fault-tolerant topology state. Subsequently, the corresponding control algorithm is adjusted in a timely manner.

[0053] It improves the reliability of the industrial robot joint motors, reduces the occurrence of robot operation interruptions due to motor failures, and ensures that the industrial robot can continue to complete various operational tasks accurately and stably.

[0054] It can be seen from these two embodiments that the open-circuit fault-tolerant topology structure and control method of the series-winding motor inverter of the present invention can effectively improve the reliability of the series-winding motor, and can achieve non-phase-lost operation of the series-winding motor after a phase arm of the series-winding motor fails, maintaining the same load capacity as before the fault.

[0055] The steady-state performance of the present invention was tested in a simulation environment. The speed was set to 100 rpm, the load was 3 N·m, and 0-0.3s was the healthy state. After 0.3s, the bridge arm L 1 An open circuit fault occurs, and the bipolar diode TR 1 conduction, A Phase winding input terminal connected to bus capacitor midpoint O The obtained speed and torque waveforms are as follows: Fig. 9 As shown; the phase current waveform and zero sequence current waveform are as follows Fig.10 As shown; the duty cycle of the four bridge arms is as follows Fig.11 shown.

[0056] It can be seen from the figure that the torque pulsation of the series winding motor is small in a healthy state, and the duty ratio of the four bridge arms is not zero. L 1 After the fault, the fault-tolerant topology is activated and the fault-tolerant control algorithm is switched. L Duty cycle of 1 d 1After the fault, the zero-sequence current value is large, but the overall performance of the series-wound motor does not change much, and the series-wound motor can still maintain the same load operation, which verifies the effectiveness of the present invention.

[0057] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0058] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A series winding motor inverter open circuit fault tolerant topology, characterized in that: It consists of four inverter bridge arms, namely bridge arm L 1. L 2. L 3. L 4, and four bipolar diodes: TR 1. TR 2. TR 3. TR 4; Two capacitors C 1 and C 2. The motor winding includes A Phase winding, B Phase winding, C Phase winding; After the inverter fails, the corresponding winding drive circuit is reconstructed so that the series winding motor can achieve phase-to-phase fault-tolerant operation when the inverter fails; A The input end of the phase winding and the bridge arm L 1 are connected to each other, the output end and the bridge arm L 2 connections; B The input end of the phase winding and the bridge arm L 2 are connected to each other, the output end and the bridge arm L 3. Interconnection; C The input end of the phase winding and the bridge arm L 3 connections, output end and bridge arm L 4-phase connection; Bipolar diode TR 1. Set the busbar midpoint O Point and bridge arm L 1Connection; TR 2. Set the busbar midpoint O Point and bridge arm L 2 connections; TR 3. Set the busbar midpoint O Point and bridge arm L 3 connections; TR 4. Set the busbar midpoint O Point and bridge arm L 4Connections.

2. The open circuit fault tolerant topology of the series winding motor inverter according to claim 1, characterized in that: When an open-circuit fault occurs in the inverter bridge arm, the fault-tolerant circuit is reconstructed by controlling the conduction of the bipolar diode to ensure that the motor runs without phase loss.

3. The open circuit fault tolerant topology of the series winding motor inverter according to claim 2, characterized in that: When the bridge arm L 1After an open circuit fault occurs, the bipolar diode is turned on TR 1. At this time A Phase winding input terminal and bus neutral point O Connect the dots, maintain A The phase winding continues to operate with fault tolerance; B , C The phase windings still maintain normal operation.

4. The open circuit fault tolerant topology of the series winding motor inverter according to claim 2, characterized in that: When the bridge arm L 2 After an open circuit fault occurs, the bipolar diode is turned on TR 2. At this time B Phase winding input terminal and bus neutral point O Connect the dots, maintain B The phase winding continues to operate with fault tolerance; A , C The phase windings still maintain normal operation.

5. The open circuit fault tolerant topology of the series winding motor inverter according to claim 2, characterized in that: When the bridge arm L 3 After an open circuit fault occurs, the bipolar diode is turned on TR 3. At this time C Phase winding input terminal and bus neutral point O Connect the dots, maintain C The phase winding continues to operate; A.B The phase windings still maintain normal operation.

6. The open circuit fault tolerant topology of the series winding motor inverter according to claim 2, characterized in that: When the bridge arm L 4 After an open circuit fault occurs, the bipolar diode is turned on TR 4. At this time C Phase winding output end and bus neutral point O Connect, maintain C The phase winding continues to operate; A , B The phase windings still maintain normal operation.

7. A control method for a series winding motor inverter open circuit fault tolerant topology of a series winding motor inverter according to any one of claims 1 to 6, characterized in that: include: When an open circuit fault is detected in one phase bridge arm of the inverter, the inverter bridge arm fault is located; The winding voltage distribution is reconstructed according to the vector space decoupling, and the series winding motor is in a fault-tolerant mode at this time; Collect current motor speed n , and set the reference motor speed ; The speed deviation control calculation is performed through the speed PI controller, and the result is projected to dqo Plane, get q Axis reference current ; set up d Axis and zero sequence axis reference current and is zero; Collect the current of each phase i A , i B , i C , after Clark transformation, the result is projected to α-β-o Plane, get i α , i β and i 0 ; Will i α , i β 、i 0 After Park transformation, the result is projected to dqo plane, get the current dqo Plane current i d , i q 、 i 0 ; The reference current , and and current dqo Flat i d , i q 、i 0 The reference voltage is obtained by the current PI controller , and ; Set the reference voltage , and Obtained by Anti-Park transformation , 、 ; Will , 、 Input to the modulation module; The modulation module can use the space vector pulse width modulation algorithm SVPWM or the carrier comparison pulse width modulation algorithm CBPWM; When the SVPWM modulation algorithm is used, the fault-tolerant voltage vector set is reconstructed according to the inverter open-circuit fault, and then the required reference voltage vector is synthesized according to the SVPWM, and finally the inverter switching sequence is output to drive the series winding motor to operate in a non-lack-phase fault-tolerant manner; When the CBPWM modulation algorithm is used, the duty cycle of each bridge arm can be obtained according to the following steps: , 、 Input to the modulation module; After the coordinate change α-β-o The reference voltage vector of the plane is converted to abc In the coordinate system, the reference value of the three-phase voltage is obtained , , ; Assume the bridge arm L 1 Open circuit fault occurs, A The phase winding input terminal is connected to the midpoint of the bus capacitor O At point , the duty cycle of each bridge arm is: Bridge arm L 1 is isolated and its duty cycle is: ； Since the bus capacitor midpoint O Point and A The phase winding input terminal is connected, and its voltage is 0.5× V dc ; Bridge arm L 2Connect A Phase winding output, bridge arm L The duty cycle of 2 is: ； in, for A Reference value of phase voltage; V dc is the DC bus voltage value; Bridge arm L The duty cycle of 3 is: ； in, for B Reference value of phase voltage; Bridge arm L The duty cycle of 4 is: ； in, for C Reference value of phase voltage; Finally, the duty cycle of each bridge arm is output to the inverter to drive the series winding motor to achieve phase-tolerant fault-free operation.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the open-circuit fault-tolerant topology control method of the series winding motor inverter as described in claim 7.

9. A computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the open-circuit fault-tolerant topology control method for a series-winding motor inverter as claimed in claim 7.

10. A three-phase series winding motor inverter, characterized in that: It includes the open circuit fault tolerant topology of the series winding motor inverter as described in any one of claims 1-6.

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