A four-motor fault-tolerant operation topology and method

Abstract

The application belongs to the technical field of motor control, and relates to a four-motor fault-tolerant working topology structure and method. The topology structure contains twelve-phase bridge arms, which are connected with No. 1 to No. 4 motors respectively, and each motor has A, B and C three-phase windings. The structure further contains four bidirectional thyristors connected with the C-phase bridge arms of the four motors. In working, the application takes the C-phase bridge arm duty cycle as a reference, calculates the optimal duty cycle of the motor with an open circuit fault, and performs fault-tolerant control on the four three-phase star-connected winding permanent magnet synchronous motors. The application not only can prolong the service life of the system, but also considers the fault-tolerant control of multiple motors, effectively improves the reliability of the motor group control system, and has important application value in the field of motor control.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor control, and particularly relates to a four-motor fault-tolerant working topology and method. BACKGROUND

[0002] With the rapid development of science and technology, the production field is marching towards the direction of intelligentization and automation. In this process, various industries have put forward higher and higher requirements for the performance of production equipment and transportation tools, especially the pursuit of more stable, efficient and accurate power control methods, aiming to perfectly adapt to the complex and changeable production operation needs. Whether it is AGV car that undertakes the task of material transportation in the factory, various precision equipment used for large-scale mechanical processing, hoisting machinery that plays a key role in the field of construction, or the booming emerging electric vehicle industry, all of them will use the technology of comprehensive control of multiple motors, and urgently need a new power driving scheme to enhance their working ability and improve the quality of work.

[0003] During the actual operation of the equipment, the fault of open circuit of the inverter phase foot exists. Once this fault occurs, the equipment that is running will be damaged, and then cause huge property loss. Therefore, when such a fault occurs, how to ensure that the equipment continues to operate normally within the specified time and achieves the intended work goal has become a key problem to be solved. The existing fault-tolerant control methods mostly focus on the fault-tolerant control strategy of a single motor, mainly adjusting the parameter mismatch of a single motor, and the core purpose is to enhance the ability of a single motor to keep running when a fault occurs. In addition, there is also a fault-tolerant control method for two-motor series systems, but this method faces extremely complex conditions in compensating for the non-sinusoidal motor magnetic motive force, which limits its effect and efficiency in actual application to a certain extent.

[0004] In a control system equipped with four independent motors, each motor has an independent drive control system. This configuration makes the system have better performance in steering and can provide higher steering capability; in terms of driving performance, it can also achieve a more scientific and reasonable power distribution ratio, thereby improving the running efficiency and flexibility of the whole system. The current technical status has some shortcomings, and there is a lack of an effective fault-tolerant working mode that comprehensively considers the working mode of four motors, especially in the case of complex fault such as open circuit of multiple motors. When multiple motors encounter such a fault, the existing technology cannot ensure that the system can still operate stably and reliably, thereby affecting the performance and reliability of the whole control system, leading to problems such as system shutdown and work interruption in actual application, and an innovative solution is needed to fill this technical gap.

[0005] The prior art 1 (CN208316611U) discloses a dual three-phase motor system and its fault-tolerant driving circuit. The system adopts a dual-winding motor, i.e., a single motor has two independent windings, which are a first set of windings and a second set of windings. Each set of windings includes A phase, B phase and C phase. The fault-tolerant design of the system relies on a redundant bridge arm structure. Through the connection of bidirectional thyristors and redundant bridge arms, when a bridge arm fault of the inverter is detected, the controller disconnects the power tube of the fault bridge arm and triggers the bidirectional thyristor to conduct, so that the fault bridge arm is replaced by the redundant bridge arm to realize the continuous operation of the motor.

[0006] The main technical features of this scheme include: 1) dual-winding motor is adopted, and the C phase of each set of windings is connected to the redundant bridge arm through bidirectional thyristors; 2) when an open-circuit fault occurs in a bridge arm, the controller switches the current path through the bidirectional thyristor, so that the system can still work normally; 3) the use of redundant bridge arms enhances the fault-tolerant capability of the system, but also increases the hardware cost and complexity of the system.

[0007] The main technical problems of this scheme include: first, the fault-tolerant structure relies on redundant bridge arms, resulting in high hardware cost of the overall system and increasing the complexity of the circuit. Second, this scheme is only applicable to dual-winding systems of a single motor, and when multiple motors are running simultaneously, this topology structure cannot be directly extended, making it difficult to adapt to the application requirements of four-motor and other multi-machine group systems. In addition, this scheme uses redundant bridge arms for fault tolerance, but does not optimize the selection strategy of the bridge arms, which may cause unnecessary resource waste and system reliability problems.

[0008] Therefore, although the scheme of the prior art 1 provides a fault-tolerant driving design, the redundant structure results in high system cost and is only applicable to dual-winding motors, which cannot meet the needs of larger-scale motor groups. At the same time, the scheme has a fixed bridge arm selection strategy and lacks flexible control methods, limiting the fault-tolerant capability of the system under different working conditions. Therefore, in the application scenario of a four-motor system, it is still necessary to explore a more optimized fault-tolerant topology structure to reduce hardware redundancy, reduce cost, and improve the flexibility and reliability of the system. SUMMARY

[0009] In view of the problems existing in the prior art, the present application provides a four-motor fault-tolerant working topology structure, which provides a fault-tolerant control, i.e., when one or two or three motor driving control bridge arms in a four-motor group have an open-circuit fault, an effective control mode is provided. The present application can comprehensively consider the control performance of the whole system and perform a fault-tolerant control. The four-motor system can operate normally when any motor bridge arm fails, the operation of the motor during the fault occurrence is continued, and the stability of the overall motor group system is maintained.

[0010] The application is implemented by a four-motor fault-tolerant operation topology, which has twelve-phase bridge arms, namely a first-phase bridge arm, a second-phase bridge arm, a third-phase bridge arm, a fourth-phase bridge arm, a fifth-phase bridge arm, a sixth-phase bridge arm, a seventh-phase bridge arm, an eighth-phase bridge arm, a ninth-phase bridge arm, a tenth-phase bridge arm, an eleventh-phase bridge arm and a twelfth-phase bridge arm.

[0011] The A-phase winding of the first motor is connected to the first-phase bridge arm, the B-phase winding of the first motor is connected to the second-phase bridge arm, and the C-phase winding of the first motor is connected to the tenth-phase bridge arm; the A-phase winding of the second motor is connected to the third-phase bridge arm, the B-phase winding of the second motor is connected to the fourth-phase bridge arm, and the C-phase winding of the second motor is connected to the eleventh-phase bridge arm; the A-phase winding of the third motor is connected to the fifth-phase bridge arm, the B-phase winding of the third motor is connected to the sixth-phase bridge arm, and the C-phase winding of the third motor is connected to the twelfth-phase bridge arm; and the A-phase winding of the fourth motor is connected to the seventh-phase bridge arm, the B-phase winding of the fourth motor is connected to the eighth-phase bridge arm, and the C-phase winding of the fourth motor is connected to the ninth-phase bridge arm.

[0012] Further, the motor combination in which an open-circuit fault occurs is one of the first motor, the second motor and the third motor, the first motor and the second motor, the first motor and the third motor, and the second motor and the third motor, the C-phase winding of the motor in which a fault occurs is connected to the output node of the ninth-phase bridge arm, and the duty cycle is allocated in consideration of the control effect of each motor, so that the control effect of the motor group fault tolerance is stabilized.

[0013] Further, the first phase upper bridge arm power switching device T1, the second phase upper bridge arm power switching device T3, the third phase upper bridge arm power switching device T5, the fourth phase upper bridge arm power switching device T7, the fifth phase upper bridge arm power switching device T9, the sixth phase upper bridge arm power switching device T11, the seventh phase upper bridge arm power switching device T13, the eighth phase upper bridge arm power switching device T15, the ninth phase upper bridge arm power switching device T17, the tenth phase upper bridge arm power switching device T19, the eleventh phase upper bridge arm power switching device T21, and the twelfth phase upper bridge arm power switching device T23 are respectively connected with a DC bus voltage; the first phase lower bridge arm power switching device T2, the second phase lower bridge arm power switching device T4, the third phase lower bridge arm power switching device T6, the fourth phase lower bridge arm power switching device T8, the fifth phase lower bridge arm power switching device T10, the sixth phase lower bridge arm power switching device T12, the seventh phase lower bridge arm power switching device T14, the eighth phase lower bridge arm power switching device T16, the ninth phase lower bridge arm power switching device T18, the tenth phase lower bridge arm power switching device T20, the eleventh phase lower bridge arm power switching device T22, and the twelfth phase lower bridge arm power switching device T24 are respectively connected with a power supply ground.

[0014] Further, the first phase upper bridge arm power switching device T1, the second phase upper bridge arm power switching device T3, the third phase upper bridge arm power switching device T5, the fourth phase upper bridge arm power switching device T7, the fifth phase upper bridge arm power switching device T9, the sixth phase upper bridge arm power switching device T11, the seventh phase upper bridge arm power switching device T13, the eighth phase upper bridge arm power switching device T15, the ninth phase upper bridge arm power switching device T17, the tenth phase upper bridge arm power switching device T19, the eleventh phase upper bridge arm power switching device T21, and the twelfth phase upper bridge arm power switching device T23 are respectively connected with a DC bus voltage; the first phase lower bridge arm power switching device T2, the second phase lower bridge arm power switching device T4, the third phase lower bridge arm power switching device T6, the fourth phase lower bridge arm power switching device T8, the fifth phase lower bridge arm power switching device T10, the sixth phase lower bridge arm power switching device T12, the seventh phase lower bridge arm power switching device T14, the eighth phase lower bridge arm power switching device T16, the ninth phase lower bridge arm power switching device T18, the tenth phase lower bridge arm power switching device T20, the eleventh phase lower bridge arm power switching device T22, and the twelfth phase lower bridge arm power switching device T24 are respectively connected with a power supply ground.

[0015] Further, the first phase upper bridge arm power switch device T1 lower node and the first phase lower bridge arm power switch device T2 upper node are connected, serving as the output node of the first phase bridge arm; the second phase upper bridge arm power switch device T3 lower node and the second phase lower bridge arm power switch device T4 upper node, serving as the output node of the second phase bridge arm; the third phase upper bridge arm power switch device T5 lower node and the third phase lower bridge arm power switch device T6 upper node, serving as the output node of the third phase bridge arm; the fourth phase upper bridge arm power switch device T7 lower node and the fourth phase lower bridge arm power switch device T8 upper node, serving as the output node of the fourth phase bridge arm; the fifth phase upper bridge arm power switch device T9 lower node and the fifth phase lower bridge arm power switch device T10 upper node, serving as the output node of the fifth phase bridge arm; the sixth phase upper bridge arm power switch device T11 lower node and the sixth phase lower bridge arm power switch device T12 upper node, serving as the output node of the sixth phase bridge arm; the seventh phase upper bridge arm power switch device T13 lower node and the seventh phase lower bridge arm power switch device T14 upper node, serving as the output node of the seventh phase bridge arm; the eighth phase upper bridge arm power switch device T15 lower node and the eighth phase lower bridge arm power switch device T16 upper node, serving as the output node of the eighth phase bridge arm; the ninth phase upper bridge arm power switch device T17 lower node and the ninth phase lower bridge arm power switch device T18 upper node, serving as the output node of the ninth phase bridge arm; the tenth phase upper bridge arm power switch device T19 lower node and the tenth phase lower bridge arm power switch device T20 upper node, serving as the output node of the tenth phase bridge arm; the eleventh phase upper bridge arm power switch device T21 lower node and the eleventh phase lower bridge arm power switch device T22 upper node, serving as the output node of the eleventh phase bridge arm; the twelfth phase upper bridge arm power switch device T23 lower node and the twelfth phase lower bridge arm power switch device T24 upper node, serving as the output node of the twelfth phase bridge arm.

[0016] Further, the C phase winding of the first motor is connected in series with a bidirectional thyristor, the C phase winding of the second motor is connected in series with a bidirectional thyristor, the C phase winding of the third motor is connected in series with a bidirectional thyristor, and the C phase winding of the fourth motor is connected in series with a bidirectional thyristor.

[0017] The application further provides a four-motor fault-tolerant operation topology control method, comprising the following steps:

[0018] S1: connecting the A phase, B phase and C phase windings of the first motor, the second motor, the third motor and the fourth motor to the corresponding bridge arms of the twelve-phase bridge arms respectively, and connecting the C phase winding to the ninth phase bridge arm through a bidirectional thyristor;

[0019] S2: when an open-circuit fault in the motor combination is detected, reconfiguring the C phase winding of the fault motor to the ninth phase bridge arm, so as to ensure that the system can continue to operate fault-tolerantly;

[0020] S3: Dynamically adjust the duty cycle based on the load status of each motor and the impact of the faulty motor, achieving balanced operation under fault conditions;

[0021] S4: Optimize bridge arm power distribution by real-time monitoring of bridge arm current and voltage, maintaining system stability and efficiency.

[0022] Further, it specifically includes the step of dynamically allocating the duty cycle:

[0023] Identify the faulty motor combination through the fault detection module;

[0024] Adjust the PWM waveform of the corresponding bridge arm according to the load demand of the non-faulty motor, maximizing the efficiency of the motor group operation;

[0025] Use feedback control mechanism to adjust the duty cycle in real time, ensuring the current balance of each motor winding, preventing secondary faults caused by single bridge arm overload.

[0026] Further, it includes the following steps of bridge arm fault detection and processing:

[0027] S1: Real-time current monitoring of the upper bridge arm power switching device and the lower bridge arm power switching device of each bridge arm;

[0028] S2: If the bridge arm current is abnormally reduced, it is determined as an open circuit fault;

[0029] S3: Reallocate the faulty motor C-phase winding to the ninth phase bridge arm and enable the bidirectional thyristor for conduction control through logical judgment;

[0030] S4: Update the system control parameters to adapt to the new bridge arm configuration after reallocation.

[0031] Further, it includes the following steps of dynamically adjusting the bridge arm operating state:

[0032] S1: Adjust the output duty cycle of the non-faulty bridge arm according to the real-time load requirement, optimizing the output current distribution;

[0033] S2: For the bridge arm with the C-phase winding reconnected, use priority scheduling algorithm to dynamically adjust its conduction timing to avoid interference with other bridge arms;

[0034] S3: Adjust the PWM duty cycle and phase angle through feedback control algorithm to ensure the optimal balance between motor group operation efficiency and control accuracy.

[0035] In combination with the above technical solutions and the technical problems solved, the technical solution to be protected by the present application has the following advantages and positive effects:

[0036] Firstly, the four-motor fault-tolerant working topology of the present application is essentially different from the prior art 1 in technical solutions. The prior art 1 relates to a "double three-phase motor" system, that is, two sets of windings of a single motor, while the scheme of the present application explicitly adopts four independent motors, each motor having A-phase, B-phase and C-phase windings, forming a complete four-motor system. The design of this topology is not simply an extension of the application of double-winding motors, but an innovative optimization for the fault-tolerant requirements of the four-motor system.

[0037] In terms of fault-tolerant mechanism, the present application adopts four bidirectional thyristors, each thyristor independently acting on the C-phase bridge arm of a single motor, thereby realizing current path reconstruction in the event of a fault. In contrast, the scheme of the prior art 1 mainly relies on a shared redundant bridge arm structure for fault tolerance, while the scheme of the present application avoids the limitations of such shared redundancy, making the fault-tolerant control of each motor more flexible and improving the independence and controllability of the system.

[0038] The present application further introduces an intelligent detection and triggering mechanism based on a system controller. When a C-phase bridge arm fault is detected, the system controller can actively adjust the working mode, timely turn off the power switch of the faulty bridge arm, and trigger the corresponding bidirectional thyristor to conduct, so that the motor group can continue to operate normally. This strategy not only enhances the fault-tolerant capability, but also improves the operation reliability of the motor group under different working conditions, rather than relying solely on redundant bridge arms.

[0039] In addition, the present application adopts a centralized control method for fault-tolerant management, rather than the independent redundancy strategy based on a single motor of the prior art 1. The advantage of centralized control is that it can uniformly coordinate the operating states of multiple motors, enabling the system to maintain overall performance efficiently in the event of a fault. At the same time, this control method also makes the implementation of the fault-tolerant strategy more refined, which helps to further optimize the stability of the system.

[0040] The fault-tolerant strategy of the present application combines the use of C-phase bridge arms and bidirectional thyristors, avoiding the problem of cost increase caused by the additional redundant bridge arms in the prior art 1. Through reasonable circuit design, this scheme reduces unnecessary hardware redundancy, while ensuring that the system can respond quickly in the event of a fault, so that the fault-tolerant capability and economy of the entire four-motor system are optimized.

[0041] In summary, the present application realizes innovation in the fault-tolerant topology structure and control strategy of the four-motor system, overcoming the limitations of the prior art and forming a unique technical solution. The scheme has outstanding substantive features and significant progress, successfully avoiding the possibility of directly deriving from the prior art 1, thereby enhancing the creativity of the present application and making it have stronger technical competitiveness in the field of motor fault tolerance.

[0042] The inverter topology provided by the application is composed of twelve-phase bridge arms, which contains twenty-four switching devices. This unique topology has high control freedom, and a single inverter topology can effectively control four three-phase motors. Compared with the previous fault-tolerant control method for only two motors, the application has significantly improved the motor fault-tolerant capability. Due to the ingenious use of bidirectional thyristors, the structure can accurately control the current on the corresponding winding of the fault motor. When the motor winding is disconnected due to a fault, through this control mechanism, the current of the fault motor winding, which was originally 0, becomes the same current as the normal motor C-phase winding, ensuring that the four motors can maintain good balance in both normal and fault-tolerant working states. Further, the application uses the C-phase bridge arm duty cycle as an important reference to accurately calculate the optimal duty cycle of the open-circuit fault motor. In this way, the duty cycle of the fault motor is adjusted from 0 after opening to an appropriate duty cycle between 0 and 1 for the C-phase winding. This fault-tolerant control method for four three-phase star-connected winding permanent magnet synchronous motors has a positive significance for extending the service life of the entire system. Considering the fault-tolerant control of multiple motors, the reliability of the motor group control system can be effectively improved.

[0043] Second, the expected income and commercial value of the technical solution of the application after transformation are: the technical solution of the application shows significant expected income and high commercial value after transformation. In terms of expected income, in key fields such as industry, transportation, and logistics, the application can effectively expand the market size by significantly improving the performance of equipment, thereby bringing direct income to enterprises. At the same time, by greatly reducing maintenance costs, enterprises can obtain indirect income, and this advantage can also effectively prevent personnel injuries and property losses caused by equipment failure. In addition, technology authorization will also become an important source of income. From the perspective of commercial value, the application can effectively improve the brand image of enterprises and enhance their competitive advantage in the market. It will also serve as a strong driving force for industry development and actively promote the technological progress of the entire industry. More importantly, the application is conducive to expanding cooperation opportunities in the industrial chain and creating more space for the development of enterprises and the entire industry.

[0044] Traditional inverter topologies have limitations in controlling the number of motors and fault tolerance. The unique inverter topology of the present invention, composed of twelve-phase bridge arms and twenty-four switching devices, breaks through the limitations of previous topologies. Previous inverters can only control a small number of motors, while the single inverter topology of the present invention can accurately control four three-phase motors, greatly expanding the application range and control ability of the inverter. Previous fault tolerance control techniques mostly focus on two-motor systems, and lack sufficient fault tolerance processing capability for multiple motors working simultaneously. The present invention breaks through in this regard, enabling efficient fault tolerance control of four motors, greatly improving the fault tolerance capability of the system when facing motor failures. The present invention uses bidirectional thyristors to control the connection and disconnection of shared duty cycle windings, allowing the motor winding phase current and corresponding phase duty cycle to rise from 0 to a more reasonable value after disconnection, further improving the performance of the system in fault tolerance state.

[0045] Third, the technical problems and significant progress of the technical solution in industrial application:

[0046] 1. The existing technical problems solved:

[0047] Traditional multi-motor drive systems often fail when a motor or its drive unit fails, causing the entire system to malfunction and unable to meet the high reliability requirements of industrial applications such as electric vehicles and parallel drive of motor groups.

[0048] Existing multi-motor drive systems lack flexible fault tolerance strategies under fault conditions, making it difficult to achieve fault isolation and resource reallocation, resulting in a significant decline in overall system performance and operating efficiency.

[0049] The bridge arm resources of a multi-motor system are usually fixed, and once a part of the resources fails, the system cannot dynamically adjust the working mode of the remaining bridge arms, resulting in serious resource waste and poor system scalability and adaptability.

[0050] In traditional bridge arm drive technology, the response speed of power switching devices is slow, and it is difficult to quickly adjust to complex motor operating conditions, resulting in low motor control precision and insufficient efficiency.

[0051] 2. Significant technical progress

[0052] The present invention uses a twelve-phase bridge arm structure and bidirectional thyristors to achieve dynamic bridge arm reconstruction, which can adjust the motor winding connection mode under various fault combinations to ensure system fault tolerance operation. This innovative fault tolerance design significantly improves the reliability of the system and is suitable for high-reliability industrial scenarios.

[0053] In the event of a failure, the system can flexibly allocate the remaining bridge arm resources and maintain stable operation by adjusting the duty cycle. Compared with traditional designs, this solution greatly improves the utilization rate of bridge arm resources and reduces resource waste caused by failures.

[0054] By optimizing the PWM waveform control strategy in real time, the system achieves high-precision current modulation of each motor winding and can dynamically adjust the workload distribution of each motor in the event of a failure, ensuring that the overall system efficiency and stability are not significantly affected.

[0055] The system uses high-speed response power switching devices and combines advanced control algorithms to achieve fast fault detection and response. The dynamic reconstruction of the bridge arm and current modulation can be completed in milliseconds, greatly improving the control accuracy and response speed under complex working conditions.

[0056] The modular design of the present invention supports flexible expansion and dynamic adaptation of multi-motor systems, and can be applied in a wide range of industrial scenarios, such as robot driving, multi-motor control systems for electric vehicles, fault-tolerant driving in aerospace, etc.

[0057] 3. Economic and environmental benefits

[0058] By reducing downtime and repair costs caused by single-point failures, the present invention reduces the operating costs of equipment in practical applications and enhances the economic benefits of industrial users.

[0059] Efficient energy transfer and resource optimization design reduces energy waste, while intelligent power distribution reduces energy consumption during equipment operation, with significant environmental benefits.

[0060] In summary, the present invention not only solves the key problems of existing technology, but also significantly improves reliability, resource utilization, and control performance, with important economic and social value. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 is the overall control topology schematic diagram provided by the embodiment of the present invention;

[0062] Figure 2 is a control example schematic diagram provided by the embodiment of the present invention;

[0063] Figure 3 is the equivalent topology schematic diagram provided by the embodiment of the present invention when there is no failure;

[0064] Figure 4 is a single-phase open-circuit fault topology schematic diagram provided by the embodiment of the present invention for a No. 1 motor;

[0065] Figure 5is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application;

[0066] Figure 6 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application;

[0067] Figure 7 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application;

[0068] Figure 8 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application;

[0069] Figure 9 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application.

[0070] Figure 10 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application. Figure 4 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application.

[0071] Figure 11 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application. Figure 6 is a single-phase open circuit fault topology diagram of a first motor according to an embodiment of the present application. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0073] The four-motor fault-tolerant working topology structure of the present application is based on four independent motors, each motor containing A-phase, B-phase and C-phase windings, and each C-phase bridge arm is in series with a bidirectional thyristor to provide fault-tolerant function. In the normal working state, the power switches of all bridge arms are normally turned on, and the four motors work according to the established driving signal. The system controller monitors the working state of each bridge arm in real time to ensure that each motor can run stably. When all bridge arms work normally, the bidirectional thyristor is in the off state, which does not affect the normal current path.

[0074] When the system detects an open-circuit or short-circuit fault in a C-phase bridge arm, for example, due to a damaged power switch that prevents normal current flow, the system controller first turns off the power switch in the faulty bridge arm to prevent damage to the motor from abnormal current. At the same time, the system controller triggers the conduction of the bidirectional thyristor connected in series with the C-phase bridge arm, establishing a new current path to allow the motor to continue running, thereby achieving fault tolerance. At this time, the C-phase winding current of the motor no longer passes through the faulty bridge arm, but flows through the thyristor after conduction, allowing the overall operation of the motor group to be unaffected by a single fault.

[0075] In fault tolerance mode, the system controller dynamically adjusts the drive signals of the faulty motor based on its state to optimize the motor's operating efficiency. For example, when a C-phase bridge arm of a motor fails, the motor's operating mode can be adjusted to a degraded mode to reduce its dependence on the C-phase winding to minimize the impact of the fault. At the same time, the system controller can adjust the operating parameters of other motors to adapt to the new current distribution, ensuring stable operation of the entire four-motor system. In addition, if a motor's fault reaches a level where it cannot continue to operate, the system can implement further redundancy control strategies, such as limiting the operation of the motor while ensuring the normal functioning of other motors.

[0076] The topology uses centralized control, allowing the system controller to monitor the operating state of the four motors in real time and dynamically adjust the fault tolerance strategy to improve the stability and reliability of the system. Compared to traditional redundant bridge arm fault tolerance solutions, the invention uses a C-phase bridge arm + bidirectional thyristor fault tolerance strategy, reducing the need for additional hardware redundancy, improving system reliability, and reducing costs. In the event of a fault, this solution can quickly switch the current path, allowing the four-motor system to continue to operate normally and improving the overall system's fault tolerance and safety.

[0077] The four-motor fault tolerance working topology provided by the invention has a total of twelve bridge arms, namely the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, and twelfth bridge arms. The four motors are labeled as Motor 1, Motor 2, Motor 3, and Motor 4. The stator winding numbers of the motors are represented by the symbols A, B, and C. Each motor has three-phase windings, namely the A-phase winding, B-phase winding, and C-phase winding. Four bidirectional thyristors are connected to the C-phase windings of the four motors.

[0078] The A-phase winding of the first motor is connected to the first phase bridge arm, the B-phase winding of the first motor is connected to the second phase bridge arm, and the C-phase winding of the first motor is connected to the tenth phase bridge arm; the A-phase winding of the second motor is connected to the third phase bridge arm, the B-phase winding of the second motor is connected to the fourth phase bridge arm, and the C-phase winding of the second motor is connected to the eleventh phase bridge arm; the A-phase winding of the third motor is connected to the fifth phase bridge arm, the B-phase winding of the third motor is connected to the sixth phase bridge arm, and the C-phase winding of the third motor is connected to the twelfth phase bridge arm; the A-phase winding of the fourth motor is connected to the seventh phase bridge arm, the B-phase winding of the fourth motor is connected to the eighth phase bridge arm, and the C-phase winding of the fourth motor is connected to the ninth phase bridge arm.

[0079] Further, the motor combination in which the open-circuit fault occurs is one of the following combinations: the first motor, the second motor and the third motor; the first motor and the second motor; the first motor and the third motor; and the second motor and the third motor, and the C-phase winding of the motor in which the fault occurs is connected to the ninth phase bridge arm, and the duty cycle is reasonably distributed to stabilize the control effect of the motor group fault tolerance by comprehensively considering the control effect of each motor.

[0080] A nine-phase bridge motor fault-tolerant working topology is provided according to Figure 1 The first phase bridge arm includes a first phase upper bridge arm power switching device T1 and a first phase lower bridge arm power switching device T2, the second phase bridge arm includes a second phase upper bridge arm power switching device T3 and a second phase lower bridge arm power switching device T4, the third phase bridge arm includes a third phase upper bridge arm power switching device T5 and a third phase lower bridge arm power switching device T6, the fourth phase bridge arm includes a fourth phase upper bridge arm power switching device T7 and a fourth phase lower bridge arm power switching device T8, the fifth phase bridge arm includes a fifth phase upper bridge arm power switching device T9 and a fifth phase lower bridge arm power switching device T10, the sixth phase bridge arm includes a sixth phase upper bridge arm power switching device T11 and a sixth phase lower bridge arm power switching device T12, the seventh phase bridge arm includes a seventh phase upper bridge arm power switching device T13 and a seventh phase lower bridge arm power switching device T14, the eighth phase bridge arm includes an eighth phase upper bridge arm power switching device T15 and an eighth phase lower bridge arm power switching device T16, the ninth phase bridge arm includes a ninth phase upper bridge arm power switching device T17 and a ninth phase lower bridge arm power switching device T18, the tenth phase bridge arm includes a tenth phase upper bridge arm power switching device T19 and a tenth phase lower bridge arm power switching device T20, the eleventh phase bridge arm includes an eleventh phase upper bridge arm power switching device T21 and an eleventh phase lower bridge arm power switching device T22, and the twelfth phase bridge arm includes a twelfth phase upper bridge arm power switching device T23 and a twelfth phase lower bridge arm power switching device T24.

[0081] The upper nodes of the first-phase upper bridge arm power switching device T1, the second-phase upper bridge arm power switching device T3, the third-phase upper bridge arm power switching device T5, the fourth-phase upper bridge arm power switching device T7, the fifth-phase upper bridge arm power switching device T9, the sixth-phase upper bridge arm power switching device T11, the seventh-phase upper bridge arm power switching device T13, the eighth-phase upper bridge arm power switching device T15, the ninth-phase upper bridge arm power switching device T17, the tenth-phase upper bridge arm power switching device T19, the eleventh-phase upper bridge arm power switching device T21, and the twelfth-phase upper bridge arm power switching device T23 are respectively connected with a direct current bus voltage; the first-phase lower bridge arm power switching device T2, the second-phase lower bridge arm power switching device T4, the third-phase lower bridge arm power switching device T6, the fourth-phase lower bridge arm power switching device T8, the fifth-phase lower bridge arm power switching device T10, the sixth-phase lower bridge arm power switching device T12, the seventh-phase lower bridge arm power switching device T14, the eighth-phase lower bridge arm power switching device T16, the ninth-phase lower bridge arm power switching device T18, the tenth-phase lower bridge arm power switching device T20, the eleventh-phase lower bridge arm power switching device T22, and the twelfth-phase lower bridge arm power switching device T24 are respectively connected with a power supply ground.

[0082] The lower node of the first-phase upper bridge arm power switching device T1 and the upper node of the first-phase lower bridge arm power switching device T2 are connected, serving as an output node of the first-phase bridge arm; the lower node of the second-phase upper bridge arm power switching device T3 and the upper node of the second-phase lower bridge arm power switching device T4 serve as an output node of the second-phase bridge arm; the lower node of the third-phase upper bridge arm power switching device T5 and the upper node of the third-phase lower bridge arm power switching device T6 serve as an output node of the third-phase bridge arm; the lower node of the fourth-phase upper bridge arm power switching device T7 and the upper node of the fourth-phase lower bridge arm power switching device T8 serve as an output node of the fourth-phase bridge arm; the lower node of the fifth-phase upper bridge arm power switching device T9 and the upper node of the fifth-phase lower bridge arm power switching device T10 serve as an output node of the fifth-phase bridge arm; the lower node of the sixth-phase upper bridge arm power switching device T11 and the upper node of the sixth-phase lower bridge arm power switching device T12 serve as an output node of the sixth-phase bridge arm; the lower node of the seventh-phase upper bridge arm power switching device T13 and the upper node of the seventh-phase lower bridge arm power switching device T14 serve as an output node of the seventh-phase bridge arm; the lower node of the eighth-phase upper bridge arm power switching device T15 and the upper node of the eighth-phase lower bridge arm power switching device T16 serve as an output node of the eighth-phase bridge arm; the lower node of the ninth-phase upper bridge arm power switching device T17 and the upper node of the ninth-phase lower bridge arm power switching device T18 serve as an output node of the ninth-phase bridge arm; the lower node of the tenth-phase upper bridge arm power switching device T19 and the upper node of the tenth-phase lower bridge arm power switching device T20 serve as an output node of the tenth-phase bridge arm; the lower node of the eleventh-phase upper bridge arm power switching device T21 and the upper node of the eleventh-phase lower bridge arm power switching device T22 serve as an output node of the eleventh-phase bridge arm; and the lower node of the twelfth-phase upper bridge arm power switching device T23 and the upper node of the twelfth-phase lower bridge arm power switching device T24 serve as an output node of the twelfth-phase bridge arm.

[0083] The four-motor fault-tolerant working topology provided by the application adopts twelve-phase bridge arm driving, each bridge arm is composed of upper and lower bridge arm power switching devices, for example, the first-phase bridge arm includes T1 and T2, and is connected to the A-phase winding of the first motor through the output node thereof. The upper bridge arm power switching device of each bridge arm is connected to the DC bus voltage, and the lower bridge arm power switching device is connected to the power supply ground. By controlling the conduction state of the upper and lower bridge arm power switching devices, a PWM waveform is formed to provide an alternating current for the motor winding and drive the motor to run.

[0084] When part of the motors fail, for example, the C-phase winding of a motor fails in an open circuit, the topology can realize fault-tolerant operation by adjusting the access point (for example, connecting the fault C-phase winding to the ninth-phase bridge arm). This strategy ensures the normal operation of the remaining motors by reasonably allocating the duty cycle of the bridge arm, maximizes the use of the remaining resources to maintain the overall performance of the motor group, and reduces the impact of the fault.

[0085] By setting the bidirectional thyristor to connect the C-phase winding of the faulty motor with the spare bridge arm (such as the ninth-phase bridge arm), the bridge arm output network can be dynamically reconstructed to ensure that the motor winding obtains a stable current driving signal. For various fault combinations (such as the simultaneous faults of the first motor, the second motor, and the third motor), the system can flexibly adjust the distribution logic, optimize the bridge arm resources through the control strategy, and meet the fault-tolerant operation requirements under different working conditions.

[0086] The power switching devices (such as T1 to T24) of each bridge arm have high-speed response characteristics, and through accurate PWM waveform modulation, the motor winding current waveform can be quickly adjusted to achieve accurate control. At the same time, the connection of the DC bus voltage and the power supply ground ensures efficient energy transfer when the power switching device is turned on, reduces power loss, and improves the overall efficiency of the system.

[0087] The control unit in the system adjusts the control signal of the power switching device in real time by detecting the operating state of each phase bridge arm and the feedback signal of the motor winding. For the motor that has failed, the control unit can redistribute the work tasks of each bridge arm and dynamically adjust the duty cycle to keep the remaining motors running stably, thereby improving the reliability and adaptability of the system.

[0088] The system quickly identifies open-circuit or short-circuit faults by monitoring the current and voltage states of the bridge arm output nodes. After detecting a fault, the system starts the fault-tolerant operation mode, and at the same time, protects the remaining normally operating bridge arms and motors through soft start and current limiting. This mechanism can effectively prevent the expansion of the fault and protect the safety of equipment and personnel.

[0089] The invention adopts the method of connecting the C-phase of the motor to the output node of the ninth-phase bridge arm, sharing the duty cycle of the C-phase, to achieve fault-tolerant control. The invention adopts the method of increasing zero-voltage control vectors to perform fault-tolerant control on the remaining motors. The specific implementation steps are as follows:

[0090] Step one, collect the duty cycle of each motor at the current control time.d ij where i represents the ith motor, and j represents the j-phase winding of the motor, such as d 1A represents the A-phase winding of the first motor. After synthesizing the C-phase duty cycles of the four motors, the maximum duty cycle is selected, and the corresponding motor is the reference motor.

[0091] Step two, according to the selected reference motor, distribute the duty cycles of the remaining faulty motors. To more specifically describe the duty cycle distribution method of the invention, a switching state as shown in Figure 2 is adopted, in which the first motor is the selected reference motor, d 1C is the maximum duty cycle of the C-phase winding of the four motors, i = 2, 3, 4, The difference between the duty cycles of the reference motor and the i-th motor.

[0092] When and ,

[0093] ,

[0094] wherein, , , is the duty cycle of the i-th motor A, B, C before distribution; , and is the duty cycle of the i-th motor A, B, and C after distribution.

[0095] When or ,

[0096] According to the formula , ,

[0097] wherein, represents the bus voltage, is the difference between the voltage reference value and the actual value, , , , are the actual value and reference value of the voltage component of the motor on the α-β axis in the stationary coordinate system, respectively.

[0098] The duty cycles of the A, B phase windings corresponding to the i-th motor can be calculated to minimize the value function , denoted as and . The size is between 0 and 1, and the newly distributed duty cycles of the i-th motor except the reference motor are , and .

[0099] Step three, according to the above steps, the most reasonable duty cycle of each motor in the fault-tolerant working mode is obtained. The reference motor can be reasonably selected among the four motors of the system, and the duty cycle of the motor is redistributed, so that the motor can efficiently follow the reference voltage value when the fault-tolerant working mode is achieved.

[0100] The faulty motor can be connected to the faulty working topology according to the method as shown in the above example, i can be (1), (1, 2), (1, 2, 3) three combination ways, different combination ways correspond to different number of faulty motors.

[0101] The selection strategy of whether the bidirectional thyristor is turned on or not when an open circuit fault occurs is as follows: when i is (1), the bidirectional thyristors corresponding to the first motor and the fourth motor are turned on; when i is (1, 2), the bidirectional thyristors corresponding to the first motor, the second motor and the fourth motor are turned on; when i is (1, 2, 3), the bidirectional thyristors corresponding to the first motor, the second motor, the third motor and the fourth motor are turned on.

[0102] To more clearly illustrate the working state of the application, the change of the bridge arm current in the application topology is briefly described below.

[0103] When i is (1), the tenth phase bridge arm and the ninth phase bridge arm change in the topology structure, as shown in Figure 7 The bridge arm current change corresponding to each changed bridge arm in this fault-tolerant working mode is shown in

[0104] When i is (1, 2), the eleventh phase bridge arm, the tenth phase bridge arm and the ninth phase bridge arm change in the topology structure, as shown in Figure 8 The bridge arm current change corresponding to each changed bridge arm in this fault-tolerant working mode is shown in

[0105] When i is (1, 2, 3), the twelfth phase bridge arm, the eleventh phase bridge arm, the tenth phase bridge arm and the ninth phase bridge arm change in the topology structure, as shown in Figure 9 The bridge arm current change corresponding to each changed bridge arm in this fault-tolerant working mode is shown in

[0106] I. The specific application field or related product of the application.

[0107] AGV car field. In large logistics warehouses, port terminals and other scenarios, AGV cars undertake heavy cargo handling and long-distance transportation tasks, with extremely high requirements for power and stability. The four-motor fault-tolerant working topology structure of the application brings significant advantages to AGV cars. The unique inverter topology structure can accurately control four three-phase motors, output powerful and stable power, and make the AGV car have higher efficiency and reliability when handling goods. For example, in the peak season of e-commerce logistics, a large amount of goods need to be quickly processed and transported, and AGV cars can continuously and stably operate with this technology, ensuring the smoothness of the logistics process. When an open circuit fault occurs in the motor phase bridge arm, the fault-tolerant control mechanism takes effect immediately, and the duty cycle is reasonably allocated to effectively control the fault motor winding current, so that the car can continue to work normally, avoiding the interruption of cargo transportation, greatly guaranteeing the efficient continuity of logistics operation, and reducing economic losses caused by equipment failure.

[0108] The application is applied to the motor driving system of the conveyor belt, and the stable and accurate operation of the conveyor belt is ensured by virtue of the accurate control capability of the four motors.Taking the automobile manufacturing assembly line as an example, the conveyor belt must be stably operated according to the strict production rhythm, so as to ensure the efficient cooperative work of each work station.The application can keep the four motors in good balance in the normal and fault-tolerant working states, effectively maintain the speed and tension stability of the conveyor belt, reduce the production line shutdown risk caused by motor failure, and greatly improve the production efficiency.Once a bridge arm open circuit fault occurs in a motor, the fault-tolerant working mode can enable the system to continue to operate, reduce the influence of the fault on the whole production line, prolong the overall service life of the conveyor belt system, reduce the equipment maintenance cost, and provide a powerful guarantee for the production and operation of enterprises.

[0109] The application is applied to the motor driving system of the conveyor belt, and the stable and accurate operation of the conveyor belt is ensured by virtue of the accurate control capability of the four motors.Taking the automobile manufacturing assembly line as an example, the conveyor belt must be stably operated according to the strict production rhythm, so as to ensure the efficient cooperative work of each work station.The application can keep the four motors in good balance in the normal and fault-tolerant working states, effectively maintain the speed and tension stability of the conveyor belt, reduce the production line shutdown risk caused by motor failure, and greatly improve the production efficiency.Once a bridge arm open circuit fault occurs in a motor, the fault-tolerant working mode can enable the system to continue to operate, reduce the influence of the fault on the whole production line, prolong the overall service life of the conveyor belt system, reduce the equipment maintenance cost, and provide a powerful guarantee for the production and operation of enterprises.

[0110] In the application, the simulation software of the three-phase permanent magnet synchronous motor is constructed under the same motor parameter condition. In the specific operation, the duty cycle of the reference motor winding C is selected, and the duty cycle of the fault motor winding C is shared. Then, the corresponding duty cycles of the other two windings of the corresponding fault motor are calculated according to the internal law of the motor. After obtaining the duty cycle, the motor is controlled based on the duty cycle. Figure 10 The corresponding bridge arm current of one of the motors is shown in the figure, where ia is the A-phase winding current of the first motor, ia1 is the A-phase winding current of the second motor, ib is the B-phase winding current of the first motor, ib1 is the B-phase winding current of the second motor, and ic is the current on the C shared bridge arm. Figure 11For the bridge arm current situation when two of the motors fail, in the figure, ia is the No. 1 motor A-phase winding current, ia1 is the No. 2 motor A-phase winding current, ia2 is the No. 3 motor A-phase winding current, ib is the No. 1 motor B-phase winding current, ib1 is the No. 2 motor B-phase winding current, ib2 is the No. 3 motor B-phase winding current, and ic is the current on the common bridge arm. It can be found through observation that the bridge arm current of the common bridge arm is larger than before the failure occurs. However, in the power supply mode of the topology of the present application, the currents of the remaining phases can maintain normal working conditions, thereby ensuring that the entire motor system can still operate stably and efficiently under the fault-tolerant control mechanism, providing a reliable solution for motor systems in practical applications when facing similar failures, and further verifying the effectiveness and feasibility of the present application in motor fault-tolerant control.

[0111] For subsequent situations with more number of motor failures, the same principle applies, and no further elaboration is made here. Theoretical reasoning and actual experiments can be carried out according to the topology structure and description method provided by the present application.

[0112] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0113] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any modification, equivalent replacement and improvement made by any person skilled in the art within the technical scope disclosed by the present application, as long as it is within the spirit and principles of the present application, should be covered within the protection scope of the present application.

Claims

1. A four-motor fault-tolerant operation topology control method, characterized by, The four-motor fault-tolerant operation topology control method comprises the following steps: S1: connecting the A-phase, B-phase and C-phase windings of the first motor, the second motor, the third motor and the fourth motor to the corresponding bridge arms of the twelve-phase bridge arms respectively, and connecting the C-phase winding to the ninth-phase bridge arm through a bidirectional thyristor; S2: when an open-circuit fault in the motor combination is detected, reconfiguring the C-phase winding of the faulty motor to the ninth-phase bridge arm to ensure that the system can continue to operate fault-tolerantly; S3: dynamically adjusting the duty cycle according to the load state of each motor and the influence of the faulty motor to achieve balanced operation under fault conditions; S4: optimizing the bridge arm power distribution by real-time monitoring of the bridge arm current and voltage to maintain system stability and efficiency; The four-motor fault-tolerant operation topology structure comprises four motors, namely the first motor, the second motor, the third motor and the fourth motor, each motor being provided with an A-phase winding, a B-phase winding and a C-phase winding; twelve bridge arms, namely the first-phase bridge arm, the second-phase bridge arm, the third-phase bridge arm, the fourth-phase bridge arm, the fifth-phase bridge arm, the sixth-phase bridge arm, the seventh-phase bridge arm, the eighth-phase bridge arm, the ninth-phase bridge arm, the tenth-phase bridge arm, the eleventh-phase bridge arm and the twelfth-phase bridge arm; four bidirectional thyristors connected to the C-phase bridge arms of the four motors to provide fault-tolerant function; The connection mode of the motor windings and the bridge arms is as follows: the A-phase winding of the first motor is connected to the first-phase bridge arm, the B-phase winding is connected to the second-phase bridge arm, and the C-phase winding is connected to the tenth-phase bridge arm; the A-phase winding of the second motor is connected to the third-phase bridge arm, the B-phase winding is connected to the fourth-phase bridge arm, and the C-phase winding is connected to the eleventh-phase bridge arm; the A-phase winding of the third motor is connected to the fifth-phase bridge arm, the B-phase winding is connected to the sixth-phase bridge arm, and the C-phase winding is connected to the twelfth-phase bridge arm; the A-phase winding of the fourth motor is connected to the seventh-phase bridge arm, the B-phase winding is connected to the eighth-phase bridge arm, and the C-phase winding is connected to the ninth-phase bridge arm; The four bidirectional thyristors are connected in series with the C-phase bridge arms of the four motors, and are triggered to conduct when a fault in the corresponding bridge arm is detected, so as to form a new current path and realize fault-tolerant operation; The fault-tolerant control strategy comprises: when an open-circuit or short-circuit fault in the C-phase bridge arm is detected, the system controller automatically closes the power switch of the faulty bridge arm and activates the corresponding bidirectional thyristor to enable the motor to continue to operate normally; The four-motor fault-tolerant operation topology structure adopts a centralized control mode, and the system controller can adjust the fault-tolerant strategy according to the real-time operating state to improve the stability and reliability of the system; The four-motor fault-tolerant operation topology control method adopts the mode of adding zero-voltage control vectors to perform fault-tolerant control on the remaining motors, and the specific implementation steps are as follows: Step one, collect the duty cycle d of each motor at the current control time ij Where i represents the i motor, j represents the j phase winding of the motor, and after synthesizing the C phase duty cycles of the four motors, the maximum duty cycle is selected, and the corresponding motor is the reference motor; Step two, distribute the duty cycle of the rest of the faulty motor according to the selected reference motor;d 1C is the maximum duty cycle in the C phase winding of the four motors, i is the motor number except the reference motor, is the difference between the duty cycle of the reference motor and the i-th motor C phase. When and then, ， wherein, , , is the duty cycle of the i-th motor A, B, C before distribution; , and is the duty cycle of the i-th motor A, B, and C after distribution; When or then, According to the formula , , wherein, represents the bus voltage, is the difference between the voltage reference value and the actual value, , , , are the actual and reference values of the voltage components of the motor on the α-β axes of the stationary reference frame, respectively. The value function The duty cycle corresponding to the A and B phase windings of the i-th motor is calculated to minimize the value function and , which is between 0 and 1. The duty cycles corresponding to the redistribution of the i-th motor, excluding the reference motor, are , and , respectively. Step three: according to the above steps, the most reasonable duty cycle of each motor in the fault-tolerant operation mode is obtained; a reference motor can be reasonably selected among the four motors of the system, and the duty cycle of the motor is redistributed to achieve the goal that the motor can efficiently follow the reference voltage value in the fault-tolerant operation mode.

2. The four-motor fault-tolerant operation topology control method of claim 1, wherein, The motor combination that occurs open circuit fault is one of the following combinations: the first motor, the second motor and the third motor; the first motor and the second motor; the first motor and the third motor; the second motor and the third motor, the C-phase winding of the motor that occurs fault is connected to the ninth phase bridge arm, considering the control effect of each motor, distributing the duty cycle, stabilizing the control effect of motor group fault tolerance.

3. The four-motor fault-tolerant operation topology control method of claim 1, wherein, The first phase bridge arm includes the first phase upper bridge arm power switching device T1 and the first phase lower bridge arm power switching device T2, the second phase bridge arm includes the second phase upper bridge arm power switching device T3 and the second phase lower bridge arm power switching device T4, the third phase bridge arm includes the third phase upper bridge arm power switching device T5 and the third phase lower bridge arm power switching device T6, the fourth phase bridge arm includes the fourth phase upper bridge arm power switching device T7 and the fourth phase lower bridge arm power switching device T8, the fifth phase bridge arm includes the fifth phase upper bridge arm power switching device T9 and the fifth phase lower bridge arm power switching device T10, the sixth phase bridge arm includes the sixth phase upper bridge arm power switching device T11 and the sixth phase lower bridge arm power switching device T12, the seventh phase bridge arm includes the seventh phase upper bridge arm power switching device T13 and the seventh phase lower bridge arm power switching device T14, the eighth phase bridge arm includes the eighth phase upper bridge arm power switching device T15 and the eighth phase lower bridge arm power switching device T16, the ninth phase bridge arm includes the ninth phase upper bridge arm power switching device T17 and the ninth phase lower bridge arm power switching device T18, the tenth phase bridge arm includes the tenth phase upper bridge arm power switching device T19 and the tenth phase lower bridge arm power switching device T20, the eleventh phase bridge arm includes the eleventh phase upper bridge arm power switching device T21 and the eleventh phase lower bridge arm power switching device T22, and the twelfth phase bridge arm includes the twelfth phase upper bridge arm power switching device T23 and the twelfth phase lower bridge arm power switching device T24.

4. The four-motor fault-tolerant operation topology control method of claim 1, wherein, The upper nodes of the first phase upper bridge arm power switching device T1, the second phase upper bridge arm power switching device T3, the third phase upper bridge arm power switching device T5, the fourth phase upper bridge arm power switching device T7, the fifth phase upper bridge arm power switching device T9, the sixth phase upper bridge arm power switching device T11, the seventh phase upper bridge arm power switching device T13, the eighth phase upper bridge arm power switching device T15, the ninth phase upper bridge arm power switching device T17, the tenth phase upper bridge arm power switching device T19, the eleventh phase upper bridge arm power switching device T21 and the twelfth phase upper bridge arm power switching device T23 are respectively connected to the DC bus voltage; the first phase lower bridge arm power switching device T2, the second phase lower bridge arm power switching device T4, the third phase lower bridge arm power switching device T6, the fourth phase lower bridge arm power switching device T8, the fifth phase lower bridge arm power switching device T10, the sixth phase lower bridge arm power switching device T12, the seventh phase lower bridge arm power switching device T14, the eighth phase lower bridge arm power switching device T16, the ninth phase lower bridge arm power switching device T18, the tenth phase lower bridge arm power switching device T20, the eleventh phase lower bridge arm power switching device T22 and the twelfth phase lower bridge arm power switching device T24 are respectively connected to the power supply ground.

5. The four-motor fault-tolerant operation topology control method of claim 1, wherein, The lower node of the first-phase upper bridge arm power switching device T1 and the upper node of the first-phase lower bridge arm power switching device T2 are connected, serving as an output node of the first-phase bridge arm; the lower node of the second-phase upper bridge arm power switching device T3 and the upper node of the second-phase lower bridge arm power switching device T4 serve as an output node of the second-phase bridge arm; the lower node of the third-phase upper bridge arm power switching device T5 and the upper node of the third-phase lower bridge arm power switching device T6 serve as an output node of the third-phase bridge arm; the lower node of the fourth-phase upper bridge arm power switching device T7 and the upper node of the fourth-phase lower bridge arm power switching device T8 serve as an output node of the fourth-phase bridge arm; the lower node of the fifth-phase upper bridge arm power switching device T9 and the upper node of the fifth-phase lower bridge arm power switching device T10 serve as an output node of the fifth-phase bridge arm; the lower node of the sixth-phase upper bridge arm power switching device T11 and the upper node of the sixth-phase lower bridge arm power switching device T12 serve as an output node of the sixth-phase bridge arm; the lower node of the seventh-phase upper bridge arm power switching device T13 and the upper node of the seventh-phase lower bridge arm power switching device T14 serve as an output node of the seventh-phase bridge arm; the lower node of the eighth-phase upper bridge arm power switching device T15 and the upper node of the eighth-phase lower bridge arm power switching device T16 serve as an output node of the eighth-phase bridge arm; the lower node of the ninth-phase upper bridge arm power switching device T17 and the upper node of the ninth-phase lower bridge arm power switching device T18 serve as an output node of the ninth-phase bridge arm; The lower node of the tenth-phase upper bridge arm power switching device T19 and the upper node of the tenth-phase lower bridge arm power switching device T20 serve as an output node of the tenth-phase bridge arm; the lower node of the eleventh-phase upper bridge arm power switching device T21 and the upper node of the eleventh-phase lower bridge arm power switching device T22 serve as an output node of the eleventh-phase bridge arm; the lower node of the twelfth-phase upper bridge arm power switching device T23 and the upper node of the twelfth-phase lower bridge arm power switching device T24 serve as an output node of the twelfth-phase bridge arm.

6. The four-motor fault-tolerant operation topology control method of claim 1, wherein, Specifically comprising the following steps of dynamically allocating duty cycles: Identifying a faulty motor combination through a fault detection module; Adjusting the PWM waveform of the corresponding bridge arm according to the load demand of the non-faulty motor to maximize the operating efficiency of the motor group; Using a feedback control mechanism to adjust the duty cycle in real time to ensure the current balance of each motor winding and prevent secondary faults caused by single-bridge arm overload.

7. The four-motor fault-tolerant operation topology control method of claim 1, wherein, Comprising the following steps of bridge arm fault detection and processing: S1: Real-time current monitoring of the upper bridge arm power switching device and the lower bridge arm power switching device of each bridge arm; S2: If an abnormal decrease in bridge arm current is detected, it is determined to be an open circuit fault; S3: Through logical judgment, the C-phase winding of the faulty motor is redistributed to the ninth-phase bridge arm, and a bidirectional thyristor is enabled for conduction control; S4: After redistribution, update the control parameters of the system to adapt to the new bridge arm configuration.

8. The four-motor fault-tolerant operation topology control method of claim 1, wherein, Comprising the following steps of dynamically adjusting the operating state of the bridge arm: S1: Adjusting the output duty cycle of the non-faulty bridge arm according to the real-time load requirement to optimize the output current distribution; S2: For the bridge arm to which the C-phase winding is reconnected, use a priority scheduling algorithm to dynamically adjust its conduction timing to avoid interference with other bridge arms; S3: Adjust the PWM duty cycle and phase angle through feedback control algorithm to ensure the optimal balance between motor group operation efficiency and control accuracy.

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