Four-motor fault-tolerant working topological structure and method

Abstract

The invention belongs to the technical field of motor control, and relates to a four-motor fault-tolerant working topological structure and method. The topological structure comprises twelve phases of bridge arms which are respectively connected with motors I to IV, and each motor is provided with A, B and C three-phase windings. The structure also comprises four bidirectional thyristors which are connected with the C-phase bridge arms of the four motors. During working, the duty ratio of the C-phase bridge arm is taken as a reference, the optimal duty ratio of the motor with the open-circuit fault is calculated, and fault-tolerant control is carried out on the four three-phase star-connected winding permanent magnet synchronous motors. The method not only can prolong the service life of the system, but also considers fault-tolerant control of a large number of 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 invention belongs to but is not limited to the field of motor control technology, and in particular relates to a four-motor fault-tolerant working topology structure and method. Background Art

[0002] With the rapid development of science and technology, the production field is making great strides towards intelligence and automation. In this process, various industries have put forward higher and higher requirements on the performance of production equipment and transportation tools, and are particularly keen on pursuing more stable, efficient and precise power control methods, aiming to perfectly adapt to the complex and changing production operation needs. Whether it is the AGV cart that undertakes the task of transporting materials within the factory, various precision equipment used for large-scale mechanical processing, lifting machinery that plays a key role in construction and other fields, 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 drive solution to enhance their own working ability and improve work quality.

[0003] During the actual operation of the equipment, the hidden danger of open circuit of the inverter phase leg is real. Once this fault occurs, the running equipment will most likely suffer severe damage, leading to huge property losses. In view of this, when such a fault occurs, how to ensure that the equipment continues to operate normally within the specified time and achieve the established work goals has become a key problem that needs to be overcome urgently. Most of the existing fault-tolerant control methods focus on the fault-tolerant control strategy of a single motor, mainly adjusting the parameter mismatch of a single motor. The core purpose is to enhance the ability of a single motor to keep running when a fault occurs. In addition, there are also fault-tolerant control methods for systems with two motors in series. However, this method faces extremely complex conditions in compensating for the magnetic motive force of non-sinusoidal motors, which limits its effect and efficiency in practical applications to a certain extent.

[0004] In a control system equipped with four independent motors, each motor has an independent drive control system. This configuration enables the system to have better performance in steering performance and provide higher steering capabilities; in terms of driving performance, it can also achieve a more scientific and reasonable power distribution ratio, thereby improving the operating efficiency and flexibility of the entire system. The current technical status is insufficient, lacking a comprehensive and integrated working mode for the four motors, especially an effective fault-tolerant working mode in complex fault situations such as open-circuit phase bridge arms of multiple motors at the same time. When multiple motors encounter such faults at the same time, the existing technology is difficult to ensure that the system can still operate stably and reliably, which in turn affects the performance and reliability of the entire control system, resulting in system shutdowns, work interruptions and other problems in actual applications. An innovative solution is urgently needed to fill this technical gap.

[0005] Prior art 1 (CN208316611U) discloses a dual three-phase motor system and a fault-tolerant drive circuit thereof. The system adopts a dual-winding motor, that is, a single motor has two independent windings, namely the first winding and the second winding, and each winding includes phase A, phase B and phase C. The fault-tolerant design of the system relies on a redundant bridge arm structure. Through the connection between the bidirectional thyristor and the redundant bridge arm, when a fault in the inverter bridge arm is detected, the controller disconnects the power tube of the faulty bridge arm and triggers the bidirectional thyristor to conduct, so that the faulty bridge arm is replaced by the redundant bridge arm to achieve continuous operation of the motor.

[0006] The main technical features of this solution include: 1) A dual-winding motor is used, and the C phase of each winding is connected to the redundant bridge arm through a bidirectional thyristor; 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 tolerance of the system, but also increases the hardware cost and complexity of the system.

[0007] The main technical problems of this solution include: first, the fault-tolerant structure relies on redundant bridge arms, which leads to high hardware cost of the overall system and increases the complexity of the circuit. Second, this solution is only applicable to the dual-winding system of a single motor. When multiple motors are running at the same time, the topology cannot be directly expanded and is difficult to adapt to the application requirements of multi-machine cluster systems such as four motors. In addition, this solution uses redundant bridge arms for fault tolerance, but does not optimize the bridge arm selection strategy, which may lead to unnecessary waste of resources and system reliability issues.

[0008] Therefore, although the solution of prior art 1 provides a fault-tolerant drive design, its redundant structure leads to high system cost and is only applicable to dual-winding motors, which cannot meet the needs of larger motor groups. At the same time, the solution is relatively fixed in the bridge arm selection strategy and lacks flexible control methods, which limits the fault tolerance of the system under different working conditions. Therefore, in the application scenario of the four-motor system, it is still necessary to explore a more optimized fault-tolerant topology to reduce hardware redundancy, reduce costs, and improve the flexibility and reliability of the system. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a four-motor fault-tolerant working topology structure and provides a fault-tolerant control, that is, when one phase of the bridge arm of one, two or three motor drive control bridge arms in a four-motor group is open-circuited, an effective control mode is provided. The present invention can comprehensively consider the overall control performance of the system and perform a fault-tolerant control. The four-motor system can operate normally when any motor bridge arm fails, and the operation of the motor with the fault continues during the working process, maintaining the stability of the overall motor group system.

[0010] The present invention is implemented as follows: a four-motor fault-tolerant working topology structure has a total of twelve bridge arms, namely, the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridge arm, the fifth bridge arm, the sixth bridge arm, the seventh bridge arm, the eighth bridge arm, the ninth bridge arm, the tenth bridge arm, the eleventh bridge arm, and the twelfth bridge arm. Motor No. 1, Motor No. 2, Motor No. 3, and Motor No. 4. Each motor has three-phase windings, namely, A-phase winding, B-phase winding, and C-phase winding. Four bidirectional thyristors are connected to the C-phase bridge arms of the four motors.

[0011] The A-phase winding of motor No. 1 is connected to the first-phase bridge arm, the B-phase winding of motor No. 1 is connected to the second-phase bridge arm, and the C-phase winding of motor No. 1 is connected to the tenth-phase bridge arm; the A-phase winding of motor No. 2 is connected to the third-phase bridge arm, the B-phase winding of motor No. 2 is connected to the fourth-phase bridge arm, and the C-phase winding of motor No. 2 is connected to the eleventh-phase bridge arm; the A-phase winding of motor No. 3 is connected to the fifth-phase bridge arm, the B-phase winding of motor No. 3 is connected to the sixth-phase bridge arm, and the C-phase winding of motor No. 3 is connected to the twelfth-phase bridge arm; the A-phase winding of motor No. 4 is connected to the seventh-phase bridge arm, the B-phase winding of motor No. 4 is connected to the eighth-phase bridge arm, and the C-phase winding of motor No. 4 is connected to the ninth-phase bridge arm.

[0012] Furthermore, the motor combination with open circuit failure is one of motor No. 1, motor No. 2, and motor No. 3; motor No. 1, motor No. 2, and motor No. 4; motor No. 1, motor No. 3, and motor No. 4; and motor No. 2, motor No. 3, and motor No. 4. The C-phase winding of the faulty motor is connected to the ninth-phase bridge arm, and the control effects of each motor are comprehensively considered, the duty cycle is allocated, and the fault-tolerant control effect of the motor group is stabilized.

[0013] Further, the first phase bridge arm includes a first phase upper bridge arm power switch device T1 and a first phase lower bridge arm power switch device T2, the second phase bridge arm includes a second phase upper bridge arm power switch device T3 and a second phase lower bridge arm power switch device T4, the third phase bridge arm includes a third phase upper bridge arm power switch device T5 and a third phase lower bridge arm power switch device T6, the fourth phase bridge arm includes a fourth phase upper bridge arm power switch device T7 and a fourth phase lower bridge arm power switch device T8, the fifth phase bridge arm includes a fifth phase upper bridge arm power switch device T9 and a fifth phase lower bridge arm power switch device T10, the sixth phase bridge arm includes a sixth phase upper bridge arm power switch device T11 and a sixth phase lower bridge arm power switch device T12, and the seventh phase bridge arm It includes a seventh-phase upper bridge arm power switch device T13 and a seventh-phase lower bridge arm power switch device T14, the eighth-phase bridge arm includes an eighth-phase upper bridge arm power switch device T15 and an eighth-phase lower bridge arm power switch device T16, the ninth-phase bridge arm includes a ninth-phase upper bridge arm power switch device T17 and a ninth-phase lower bridge arm power switch device T18, the tenth-phase bridge arm includes a tenth-phase upper bridge arm power switch device T19 and a tenth-phase lower bridge arm power switch device T20, the eleventh-phase bridge arm includes an eleventh-phase upper bridge arm power switch device T21 and an eleventh-phase lower bridge arm power switch device T22, and the twelfth-phase bridge arm includes a twelfth-phase upper bridge arm power switch device T23 and a twelfth-phase lower bridge arm power switch device T24.

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

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

[0016] Furthermore, the C-phase winding of motor No. 1 is connected in series with a bidirectional thyristor, the C-phase winding of motor No. 2 is connected in series with a bidirectional thyristor, the C-phase winding of motor No. 3 is connected in series with a bidirectional thyristor, and the C-phase winding of motor No. 4 is connected in series with a bidirectional thyristor.

[0017] The present invention also provides a four-motor fault-tolerant working topology control method, comprising the following steps: S1: Connect the A-phase, B-phase and C-phase windings of the No. 1 motor, the No. 2 motor, the No. 3 motor and the No. 4 motor to the corresponding bridge arms of the twelve-phase bridge arms respectively, and connect the C-phase winding to the ninth-phase bridge arm through a bidirectional thyristor; S2: When an open circuit fault is detected in the motor combination, the C-phase winding of the faulty motor is reconfigured to the ninth-phase bridge arm to ensure that the system can continue to operate with fault tolerance; S3: Dynamically adjust the duty cycle according to the load status of each motor and the impact of the faulty motor to achieve balanced operation under fault conditions; S4: Optimize bridge arm power distribution and maintain system stability and efficiency by real-time monitoring of bridge arm current and voltage.

[0018] Further, the step of dynamically allocating the duty cycle is specifically included: Identify faulty motor combinations through a fault detection module; According to the load demand of the non-faulty motor, the PWM waveform of the corresponding bridge arm is adjusted to maximize the operating efficiency of the motor group; The duty cycle is adjusted in real time using the feedback control mechanism to ensure current balance in each motor winding and prevent secondary faults caused by overload of a single bridge arm.

[0019] Further, the following steps of bridge arm fault detection and processing are included: S1: Perform real-time current monitoring on the upper bridge arm power switch device and the lower bridge arm power switch device of each bridge arm; S2: If an abnormal drop in the bridge arm current is detected, it is determined to be an open circuit fault; S3: through logical judgment, select to reallocate the C-phase winding of the faulty motor to the ninth-phase bridge arm, and enable the bidirectional thyristor for conduction control; S4: After reallocation, the control parameters of the system are updated to adapt to the new bridge arm configuration.

[0020] Further, the method includes the following steps of dynamically adjusting the operating state of the bridge arm: S1: Adjust the output duty cycle of the non-fault bridge arm according to the real-time load requirements to optimize the output current distribution; S2: For the bridge arm to which the C-phase winding is reconnected, the priority scheduling algorithm is used to dynamically adjust its conduction timing to avoid interference with other bridge arms; S3: The PWM duty cycle and phase angle are adjusted by the technical solution algorithm of the present invention through feedback control to ensure the optimal balance between the operating efficiency and control accuracy of the motor group.

[0021] 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 four-motor fault-tolerant working topology of the present invention is essentially different from the prior art 1 in terms of technical solution. Prior art 1 involves a "dual three-phase motor" system, that is, two sets of windings of a single motor, while the solution of the present invention explicitly adopts four independent motors, each of which has A-phase, B-phase and C-phase windings, forming a complete four-motor system. The design of this topology is not a simple expansion of the application of dual-winding motors, but an innovative optimization for the fault-tolerant requirements of the four-motor system.

[0022] In terms of fault tolerance mechanism, the present invention uses four bidirectional thyristors, each of which acts independently on the C-phase bridge arm of a single motor, thereby realizing the current path reconstruction in case of a fault. In contrast, the solution of prior art 1 mainly relies on a shared redundant bridge arm structure for fault tolerance, while the solution of the present invention avoids the limitations of such shared redundancy, making the fault tolerance control of each motor more flexible and improving the independence and controllability of the system.

[0023] The present invention further introduces an intelligent detection and triggering mechanism based on the system controller. When a C-phase bridge arm fault is detected, the system controller can actively adjust the working mode, turn off the power switch of the faulty bridge arm in time, and trigger the corresponding bidirectional thyristor to turn on, so that the motor group can continue to operate normally. This strategy not only enhances the fault tolerance capability, but also improves the operating reliability of the motor group under different working conditions, rather than relying solely on redundant bridge arms.

[0024] In addition, the present invention adopts a centralized control method for fault-tolerant management, rather than the independent redundant strategy based on a single motor in the prior art 1. The advantage of centralized control is that it can coordinate the operating status of multiple motors in a unified manner, so that the system can still maintain the 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.

[0025] The fault-tolerant strategy of the present invention combines the use of the C-phase bridge arm with the bidirectional thyristor, avoiding the cost increase problem caused by the additional redundant bridge arm in the prior art 1. Through reasonable circuit design, the solution reduces unnecessary hardware redundancy and ensures that the system can respond quickly when a fault occurs, thereby optimizing the fault tolerance and economy of the entire four-motor system.

[0026] In summary, the present invention has achieved innovation in the fault-tolerant topology and control strategy of the four-motor system, overcomes the limitations of the prior art, and forms a unique technical solution. The solution has outstanding substantive features and significant progress, successfully avoiding the possibility of direct derivation from the prior art 1, thereby enhancing the creativity of the present invention and making it more technically competitive in the field of motor fault tolerance.

[0027] The inverter topology provided by the present invention is composed of a twelve-phase bridge arm, which includes twenty-four switching devices. This unique topology has a high degree of 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 present invention has achieved a significant improvement in the fault tolerance of the motor. Due to the clever use of bidirectional thyristors, the structure can accurately control the current on the corresponding winding of the faulty motor. When a fault occurs and causes the motor winding to be disconnected, through this control mechanism, the current of the faulty motor winding, which originally has a current of 0, can be changed to a current with the same amplitude as the C-phase winding of the normal motor, thereby ensuring that the four motors can maintain a good balance whether in normal working state or in fault-tolerant working state. Further, the present invention uses the C-phase bridge arm duty cycle as an important reference basis to accurately calculate the optimal duty cycle of the motor with an open circuit fault. In this way, the duty cycle of the faulty motor is adjusted from 0 after the open circuit to a suitable duty cycle of the C-phase winding between 0 and 1. This fault-tolerant control method for four three-phase star-connected permanent magnet synchronous motors has a positive significance for extending the service life of the entire system. Taking into account the fault-tolerant control of a large number of motors, the reliability of the motor group control system can be effectively improved.

[0028] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: the technical solution of the present invention shows significant expected benefits and extremely high commercial value after transformation. In terms of expected benefits, in key areas such as industry, transportation, and logistics, the present invention can effectively expand the market scale by virtue of its excellent improvement in equipment performance, thereby bringing direct benefits to the enterprise. At the same time, by significantly reducing maintenance costs, enterprises can obtain indirect benefits, and this advantage can also effectively prevent casualties and property losses caused by equipment failure. In addition, technology licensing will also become one of the important sources of income. From the perspective of commercial value, the present invention can effectively enhance the brand image of the enterprise and enhance its competitive advantage in the market. It will also serve as a powerful driving force for the development of the industry and actively promote technological progress in the entire industry. More importantly, the present invention is conducive to expanding cooperation opportunities in the industrial chain and creating a broader development space for enterprises and the entire industry.

[0029] The traditional inverter topology has limitations in controlling the number of motors and fault tolerance. The unique inverter topology of the present invention, which consists of 24 switching devices in a twelve-phase bridge arm, breaks through the limitations of previous topologies. Previous inverters can often 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 capabilities of the inverter. Most of the previous fault-tolerant control technologies were concentrated on two motor systems, and the fault-tolerant processing capabilities for multiple motors working simultaneously were insufficient. The present invention has achieved a breakthrough in this regard, and can perform efficient fault-tolerant control on four motors, greatly improving the fault-tolerant capability of the system in the face of motor failures compared to traditional methods. The present invention uses a bidirectional thyristor to control whether the shared duty cycle winding is connected or not, and can increase the phase current of the motor winding and the corresponding phase duty cycle after the circuit is broken from 0 to a more reasonable value, further improving the performance of the system in a fault-tolerant state.

[0030] Third, technical problems and significant progress in industrial application of technical solutions: 1. Existing technical problems solved: When a motor or its drive unit fails in a traditional multi-motor drive system, the entire system usually fails and cannot adapt to industrial applications with high reliability requirements, such as electric vehicles and parallel drives of motor groups.

[0031] Existing multi-motor drive systems lack flexible fault-tolerant strategies in the event of faults, making it difficult to achieve fault isolation and resource reallocation, resulting in a significant decline in the performance and operating efficiency of the overall system.

[0032] The bridge arm resources of a multi-motor system are usually fixed in configuration. Once some of the resources fail, the system cannot dynamically adjust the working mode of the remaining bridge arms, resulting in serious waste of resources and poor system scalability and adaptability.

[0033] In traditional bridge arm drive technology, the response speed of the power switching device is slow, and it is impossible to quickly adjust to the much more complex motor operating conditions, resulting in low motor control accuracy and insufficient efficiency.

[0034] 2. Significant technological progress 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 access mode under various fault combination conditions to ensure fault-tolerant operation of the system. This innovative fault-tolerant design significantly improves the reliability of the system and is suitable for industrial scenarios with high reliability requirements.

[0035] In the event of a fault, 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 the waste of resources caused by faults.

[0036] 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 fault, ensuring that the overall operating efficiency and stability of the system are not significantly affected.

[0037] The system uses high-speed response power switching devices and combines them with advanced control algorithms to achieve rapid fault detection and response. The dynamic reconstruction and current modulation of the bridge arm can be completed in milliseconds, greatly improving the control accuracy and response speed under complex working conditions.

[0038] 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 drives, multi-motor control systems for electric vehicles, fault-tolerant drives in the aerospace field, etc.

[0039] 3. Economic and environmental benefits 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.

[0040] Efficient energy transmission and resource optimization design reduce energy waste, while intelligent power distribution reduces energy consumption during equipment operation, which has significant environmental benefits.

[0041] In summary, the present invention not only solves the key problems of the prior art in industrial applications, but also brings about significant improvements in reliability, resource utilization, and control performance, and has important economic and social value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of the overall control topology provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a control example provided by an embodiment of the present invention; Figure 3 is a schematic diagram of an equivalent topology when there is no fault provided by an embodiment of the present invention; Figure 4 1 is a topological diagram of a single-phase open circuit fault of a No. 1 motor provided by an embodiment of the present invention; Figure 5 This is a topological diagram of a single-phase open circuit fault occurring in motors No. 1 and No. 2 provided in an embodiment of the present invention; Figure 6 1 is a topological diagram of a single-phase open circuit fault occurring in motors 1, 2, and 3 provided by an embodiment of the present invention; Figure 7 is a schematic diagram of a curve showing a change in the bridge arm current when a single-phase open circuit fault occurs in a No. 1 motor provided by an embodiment of the present invention; Figure 81 is a schematic diagram of a change curve of the bridge arm current when a single-phase open circuit fault occurs in the No. 1 and No. 2 motors according to an embodiment of the present invention; Fig. 9 1 is a schematic diagram of the change curve of the bridge arm current when the No. 1, No. 2 and No. 3 motors have a single-phase open circuit fault provided by an embodiment of the present invention; Fig.10 The present invention Figure 4 Schematic diagram of the operating bridge arm current curve under the corresponding state; Fig.11 The present invention Figure 6 Schematic diagram of the operating bridge arm current curve under the corresponding state. DETAILED DESCRIPTION

[0043] 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 used to limit the present invention.

[0044] The four-motor fault-tolerant working topology of the present invention is based on four independent motors, each of which includes A-phase, B-phase and C-phase windings, and the C-phase bridge arm is connected in series with a bidirectional thyristor to provide a fault-tolerant function. Under normal working conditions, the power switches of all bridge arms are turned on normally, and the four motors work according to the established drive signals. The system controller monitors the working status of each bridge arm in real time to ensure that each motor can operate stably. When all bridge arms are working normally, the bidirectional thyristor is in the off state and does not affect the normal current path.

[0045] When the system detects an open circuit or short circuit fault in a C-phase bridge arm, for example, the current cannot flow normally due to damage to the power switch, the system controller first turns off the power switch of the faulty bridge arm to prevent the motor from being damaged by abnormal current. At the same time, the system controller triggers the bidirectional thyristor in series with the C-phase bridge arm to conduct, establish a new current path, so that the motor can continue to run, thereby realizing fault tolerance. At this time, the C-phase winding current of the motor no longer passes through the faulty bridge arm, but maintains the current flow after the thyristor is turned on, so that the overall operation of the motor group is not affected by a single fault.

[0046] In fault-tolerant mode, the system controller dynamically adjusts the drive signal of the faulty motor according to the state of the faulty motor to optimize the motor's operating efficiency. For example, when the C-phase bridge arm of a motor fails, the motor's operating mode can be adjusted to a degraded mode to reduce 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 and maintain stable operation of the entire four-motor system. In addition, if the failure of a motor reaches a level where it cannot continue to operate, the system can adopt further redundant control strategies, such as limiting the operation of the motor while ensuring the normal function of other motors.

[0047] This topology adopts a centralized control method, which enables the system controller to monitor the working status of the four motors in real time and dynamically adjust the fault-tolerant strategy to improve the stability and reliability of the system. Compared with the traditional redundant bridge arm fault-tolerant solution, the present invention adopts the C-phase bridge arm + bidirectional thyristor fault-tolerant strategy, which reduces the additional hardware redundancy, improves the reliability of the system, and reduces the cost. When a fault occurs, the solution can quickly switch the current path so that the four-motor system can continue to work normally, improving the fault resistance and safety of the overall system.

[0048] The four-motor fault-tolerant working topology structure provided by the present invention has a total of twelve-phase 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. Motor No. 1, Motor No. 2, Motor No. 3, Motor No. 4. The stator windings of the motors are numbered with symbols A, B, and C. Each motor has three-phase windings, namely, A-phase winding, B-phase winding, and C-phase winding. Four bidirectional thyristors are connected to the C-phase windings of the four motors.

[0049] The A-phase winding of motor No. 1 is connected to the first-phase bridge arm, the B-phase winding of motor No. 1 is connected to the second-phase bridge arm, and the C-phase winding of motor No. 1 is connected to the tenth-phase bridge arm; the A-phase winding of motor No. 2 is connected to the third-phase bridge arm, the B-phase winding of motor No. 2 is connected to the fourth-phase bridge arm, and the C-phase winding of motor No. 2 is connected to the eleventh-phase bridge arm; the A-phase winding of motor No. 3 is connected to the fifth-phase bridge arm, the B-phase winding of motor No. 3 is connected to the sixth-phase bridge arm, and the C-phase winding of motor No. 3 is connected to the twelfth-phase bridge arm; the A-phase winding of motor No. 4 is connected to the seventh-phase bridge arm, the B-phase winding of motor No. 4 is connected to the eighth-phase bridge arm, and the C-phase winding of motor No. 4 is connected to the ninth-phase bridge arm.

[0050] Furthermore, the motor combination with open circuit failure is one of motor No. 1, motor No. 2, and motor No. 3; motor No. 1, motor No. 2, and motor No. 4; motor No. 1, motor No. 3, and motor No. 4; and motor No. 2, motor No. 3, and motor No. 4. The C-phase winding of the faulty motor is connected to the ninth-phase bridge arm, and the control effects of each motor are comprehensively considered, the duty cycle is reasonably allocated, and the fault-tolerant control effect of the motor group is stabilized.

[0051] A nine-phase bridge motor fault-tolerant working topology, reference Figure 1 , the switch device is represented by the symbol T. The first phase bridge arm includes the first phase upper bridge arm power switch device T1 and the first phase lower bridge arm power switch device T2, the second phase bridge arm includes the second phase upper bridge arm power switch device T3 and the second phase lower bridge arm power switch device T4, the third phase bridge arm includes the third phase upper bridge arm power switch device T5 and the third phase lower bridge arm power switch device T6, the fourth phase bridge arm includes the fourth phase upper bridge arm power switch device T7 and the fourth phase lower bridge arm power switch device T8, the fifth phase bridge arm includes the fifth phase upper bridge arm power switch device T9 and the fifth phase lower bridge arm power switch device T10, the sixth phase bridge arm includes the sixth phase upper bridge arm power switch device T11 and the sixth phase lower bridge arm power switch device T12, the seventh phase bridge arm includes the seventh phase upper bridge arm power switch device T13 and the seventh phase lower bridge arm power switch device T14. It includes a seventh-phase upper bridge arm power switch device T13 and a seventh-phase lower bridge arm power switch device T14, the eighth-phase bridge arm includes an eighth-phase upper bridge arm power switch device T15 and an eighth-phase lower bridge arm power switch device T16, the ninth-phase bridge arm includes a ninth-phase upper bridge arm power switch device T17 and a ninth-phase lower bridge arm power switch device T18, the tenth-phase bridge arm includes a tenth-phase upper bridge arm power switch device T19 and a tenth-phase lower bridge arm power switch device T20, the eleventh-phase bridge arm includes an eleventh-phase upper bridge arm power switch device T21 and an eleventh-phase lower bridge arm power switch device T22, and the twelfth-phase bridge arm includes a twelfth-phase upper bridge arm power switch device T23 and a twelfth-phase lower bridge arm power switch device T24.

[0052] The upper nodes of the first phase upper bridge arm power switch device T1, the second phase upper bridge arm power switch device T3, the third phase upper bridge arm power switch device T5, the fourth phase upper bridge arm power switch device T7, the fifth phase upper bridge arm power switch device T9, the sixth phase upper bridge arm power switch device T11, the seventh phase upper bridge arm power switch device T13, the eighth phase upper bridge arm power switch device T15, the ninth phase upper bridge arm power switch device T17, the tenth phase upper bridge arm power switch device T19, the eleventh phase upper bridge arm power switch device T21, and the twelfth phase upper bridge arm power switch device T23 are respectively connected to the DC bus. voltage; the first phase lower bridge arm power switch device T2, the second phase lower bridge arm power switch device T4, the third phase lower bridge arm power switch device T6, the fourth phase lower bridge arm power switch device T8, the fifth phase lower bridge arm power switch device T10, the sixth phase lower bridge arm power switch device T12, the seventh phase lower bridge arm power switch device T14, the eighth phase lower bridge arm power switch device T16, the ninth phase lower bridge arm power switch device T18, the tenth phase lower bridge arm power switch device T20, the eleventh phase lower bridge arm power switch device T22, and the twelfth phase lower bridge arm power switch device T24 are connected to the power ground respectively.

[0053] The lower node of the first-phase upper bridge arm power switch device T1 and the upper node of the first-phase lower bridge arm power switch device T2 are connected as the output node of the first-phase bridge arm; the lower node of the second-phase upper bridge arm power switch device T3 and the upper node of the second-phase lower bridge arm power switch device T4 are used as the output node of the second-phase bridge arm; the lower node of the third-phase upper bridge arm power switch device T5 and the upper node of the third-phase lower bridge arm power switch device T6 are used as the output node of the third-phase bridge arm; the lower node of the fourth-phase upper bridge arm power switch device T7 and the upper node of the fourth-phase lower bridge arm power switch device T8 are used as the output node of the fourth-phase bridge arm; the lower node of the fifth-phase upper bridge arm power switch device T9 and the upper node of the fifth-phase lower bridge arm power switch device T10 are used as the output node of the fifth-phase bridge arm; the lower node of the sixth-phase upper bridge arm power switch device T11 and the upper node of the sixth-phase lower bridge arm power switch device T12 are used as the output node of the sixth-phase bridge arm; the seventh-phase upper bridge arm The lower node of the power switch device T13 and the upper node of the seventh-phase lower bridge arm power switch device T14 serve as the output node of the seventh-phase bridge arm; the lower node of the eighth-phase upper bridge arm power switch device T15 and the upper node of the eighth-phase lower bridge arm power switch device T16 serve as the output node of the eighth-phase bridge arm; the lower node of the ninth-phase upper bridge arm power switch device T17 and the upper node of the ninth-phase lower bridge arm power switch device T18 serve as the output node of the ninth-phase bridge arm; the lower node of the tenth-phase upper bridge arm power switch device T19 and the upper node of the tenth-phase lower bridge arm power switch device T20 serve as the output node of the tenth-phase bridge arm; the lower node of the eleventh-phase upper bridge arm power switch device T21 and the upper node of the eleventh-phase lower bridge arm power switch device T22 serve as the output node of the eleventh-phase bridge arm; the lower node of the twelfth-phase upper bridge arm power switch device T23 and the upper node of the twelfth-phase lower bridge arm power switch device T24 serve as the output node of the twelfth-phase bridge arm.

[0054] The four-motor fault-tolerant working topology provided by the present invention adopts a twelve-phase bridge arm drive, and each bridge arm is composed of upper and lower bridge arm power switch devices. For example, the first phase bridge arm includes T1 and T2, which are connected to the A-phase winding of the first motor through its output node. The upper bridge arm power switch device of each bridge arm is connected to the DC bus voltage, and the lower bridge arm power switch device is connected to the power ground. By controlling the conduction state of the upper and lower bridge arm power switch devices, a PWM waveform is formed to provide AC current to the motor winding to drive the motor to run.

[0055] When some motors fail, such as an open-circuit fault in the C-phase winding of a motor, the topology can achieve fault-tolerant operation by adjusting its access point (such as connecting the faulty C-phase winding to the ninth-phase bridge arm). This strategy ensures the normal operation of the remaining motors by properly allocating the duty cycle of the bridge arm, while maximizing the use of the remaining resources to maintain the overall performance of the motor group and reduce the impact of the fault.

[0056] By setting up a 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 drive signal. For multiple fault combinations (such as the simultaneous failure of motors 1, 2, and 3), the system can flexibly adjust the allocation logic and optimize the bridge arm resources through control strategies to meet the fault-tolerant operation requirements under different working conditions.

[0057] The power switch devices of each bridge arm (such as T1 to T24) have high-speed response characteristics. Through accurate PWM waveform modulation, the motor winding current waveform can be quickly adjusted to achieve precise control. At the same time, the connection between the DC bus voltage and the power ground ensures efficient energy transfer of the power switch devices when they are turned on, reducing power loss and improving the overall efficiency of the system.

[0058] The control unit in the system adjusts the control signal of the power switch device in real time by detecting the operating status of each phase bridge arm and the feedback signal of the motor winding. For a motor with a fault, the control unit can reallocate 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.

[0059] The system quickly identifies open circuit or short circuit faults by monitoring the current and voltage status of the bridge arm output nodes. After detecting a fault, the system starts the fault-tolerant operation mode and protects the remaining normally operating bridge arms and motors by means of soft start and current limiting. This mechanism can effectively prevent the fault from expanding and ensure the safety of equipment and personnel.

[0060] The invention connects the motor C phase to the output node of the ninth phase bridge arm and shares the duty cycle of the C phase to achieve the purpose of fault-tolerant control. The invention adopts the method of adding a zero voltage control vector to perform fault-tolerant control on the remaining motors. The specific implementation steps are as follows: Step 1: Collect the duty cycle of each motor at the current control moment. ij , where i represents the i-th motor and j represents the j-phase winding of the motor, such as d 1A Represents the A-phase winding of motor No. 1. After integrating the C-phase duty cycles of the four motors, the largest duty cycle is selected, and the corresponding motor is the reference motor.

[0061] Step 2: Allocate the duty ratios of the remaining faulty motors based on the selected reference motor. Figure 2 A switching state shown in the figure, motor No. 1 is the selected reference motor, d 1C is the maximum duty cycle of the four motor C-phase windings, , is the difference in duty cycle between motor number 1 and motor number i C.

[0062] when and hour, ; in, , , To allocate the duty cycle corresponding to motor A, B, and C before i; , and is the duty cycle corresponding to motor A, B and C after allocation.

[0063] when or hour, According to the formula , , in, represents the bus voltage, is the difference between the voltage reference value and the actual value, , , , They are respectively the actual value and reference value of the voltage component on the α-β axis of the motor in the stationary coordinate system.

[0064] The value function can be calculated The duty ratio of the A and B phase windings corresponding to the i-th motor when it is the smallest is recorded as and Its value is between 0 and 1. Finally, except for the reference motor, the corresponding redistributed duty cycle of the i-th motor is , and .

[0065] Step 3: 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 from the four motors in the system, and the duty cycle of the motor can be redistributed to achieve the goal that the motor can efficiently follow the reference voltage value in the fault-tolerant working mode.

[0066] The faulty motor can be connected to the faulty working topology according to the method in the above example. The i value can be selected in three combinations: (2), (2, 3), and (2, 3, 4). Different combinations correspond to different numbers of faulty motors.

[0067] The following is a strategy for selecting whether to turn on or off the bidirectional thyristor when an open circuit fault occurs. When i is (2), the bidirectional thyristors corresponding to motors No. 1 and No. 4 are turned on; when i is (2, 3), the bidirectional thyristors corresponding to motors No. 1, No. 2, and No. 4 are turned on; when i is (2, 3, 4), the bidirectional thyristors corresponding to motors No. 1, No. 2, No. 3, and No. 4 are turned on.

[0068] In order to more clearly illustrate the working state of the present invention, the change of the bridge arm current in the topology of the present invention is briefly described below.

[0069] When i is (2), the topological structures of the tenth phase bridge arm and the ninth phase bridge arm change, as shown in Figure 7 The figure shows the change of the bridge arm current corresponding to each changing bridge arm in this fault-tolerant working mode.

[0070] i is (2, 3) The eleventh phase bridge arm, the tenth phase bridge arm and the ninth phase bridge arm have changed in topological structure, such as Figure 7 The figure shows the change of the bridge arm current corresponding to each changing bridge arm in this fault-tolerant working mode.

[0071] i is (2, 3, 4) and the topological structures of the twelfth phase bridge arm, the eleventh phase bridge arm, the tenth phase bridge arm and the ninth phase bridge arm have changed, such as Figure 8 and Fig. 9 As shown, the change of the bridge arm current corresponding to each changing bridge arm in this fault-tolerant working mode.

[0072] Specific application fields or related products of the present invention:

[0073] AGV cart field. In scenarios such as large logistics warehouses and port terminals, AGV carts are responsible for heavy cargo handling and long-distance transportation tasks, and have extremely high requirements for power and stability. The four-motor fault-tolerant working topology of the present invention brings significant advantages to the AGV cart. Its unique inverter topology can accurately control four three-phase motors and output strong and stable power, so that the AGV cart has higher efficiency and reliability when transporting goods. For example, during the peak season of e-commerce logistics, a large amount of goods need to be processed and transported quickly. With this technology, the AGV cart can operate continuously and stably to ensure 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. By reasonably adjusting the duty cycle, the current of the faulty motor winding is effectively controlled, so that the car can continue to work normally, avoiding interruptions in cargo transportation, greatly ensuring the efficient continuity of logistics operations, and reducing economic losses caused by equipment failures.

[0074] Conveyor belt field. In various industrial production lines, conveyor belts play a key role in material transportation, and their operating stability directly affects production efficiency. After the present invention is applied to the conveyor belt motor drive system, the smooth and precise operation of the conveyor belt is ensured by virtue of the precise control ability of the four motors. Taking the automobile manufacturing assembly line as an example, the conveyor belt must run stably according to a strict production rhythm to ensure the efficient and coordinated operation of each workstation. The present invention enables the four motors to maintain a good balance in both normal and fault-tolerant working conditions, effectively maintains the speed and tension stability of the conveyor belt, reduces the risk of production line shutdown due to motor failure, and greatly improves production efficiency. Once a motor has an open-circuit bridge arm failure, the fault-tolerant working mode allows the system to continue to operate, reducing the impact of the failure on the entire production line, while extending the overall service life of the conveyor belt system, reducing equipment maintenance costs, and providing strong guarantees for the company's production operations.

[0075] Four-wheel drive electric locomotive field. Four-wheel drive electric locomotives undertake important tasks of heavy-load freight and high-speed passenger transportation in railway transportation, and have extremely high requirements for power performance and operational reliability. After the present invention is applied to its drive system, it provides efficient and stable power output for four motors. Under working conditions such as heavy-load freight trains climbing or high-speed passenger trains accelerating, the four motors can accurately distribute power according to actual needs and work together to effectively improve the operating efficiency and safety of the train. For example, in mountain railway transportation, the train needs strong traction to overcome the slope resistance. The present invention ensures that the motor can output power stably to ensure the safe driving of the train. When a phase bridge arm open circuit fault occurs in a motor during the operation of the locomotive, the fault-tolerant control technology plays a key role, enabling the locomotive to continue to operate and ensure the normal order of railway transportation. By reasonably adjusting the duty cycle and controlling the current, the impact of the faulty motor on the entire drive system is reduced, so that the locomotive can complete the transportation task or arrive at the maintenance site safely within the specified time, reducing train delays and transportation interruptions caused by faults, and having a positive and important impact on the reliability and economy of railway transportation.

[0076] In the present invention, the simulation software construction work of the three-phase permanent magnet synchronous motor is carried out under the same motor parameter conditions. In the specific operation, the duty cycle of the reference motor winding C is selected and shared with the duty cycle of the faulty motor winding C. Then, the duty cycles corresponding to the other two phase windings of the corresponding faulty motor are calculated according to the inherent law of the motor. After obtaining the duty cycle, the motor is controlled based on it. Fig.10 The figure shows the corresponding bridge arm current after one of the motors fails. In this figure, ia is the A-phase winding current of motor No. 1, ia1 is the A-phase winding current of motor No. 2, ib is the B-phase winding current of motor No. 1, ib1 is the B-phase winding current of motor No. 2, and ic is the current on the C common bridge arm. Fig.11The figure shows the bridge arm current when two of the motors fail. In this figure, ia is the A-phase winding current of motor No. 1, ia1 is the A-phase winding current of motor No. 2, ia2 is the A-phase winding current of motor No. 3, ib is the B-phase winding current of motor No. 1, ib1 is the B-phase winding current of motor No. 2, ib2 is the B-phase winding current of motor No. 3, and ic is the current on the C common bridge arm. It can be found from observation that the bridge arm current of the common bridge arm has increased compared to before the failure. However, under the topological power supply mode of the present invention, the currents of the remaining phases can maintain a normal working state, 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 invention in motor fault-tolerant control.

[0077] The subsequent situation of more motor failures has the same principle as this situation, and no further elaboration is given here. Theoretical reasoning and actual experiments can also be performed according to the topological structure and explanation method provided by the present invention.

[0078] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0079] 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 modification, equivalent substitution and improvement 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 four-motor fault-tolerant working topology structure, characterized in that: The four-motor fault-tolerant working topology structure includes: four motors, namely motor No. 1, motor No. 2, motor No. 3, and motor No. 4, each motor being provided with an A-phase winding, a B-phase winding, and a C-phase winding; Twelve 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; Four bidirectional thyristors are connected to the C-phase bridge arms of the four motors respectively to provide fault tolerance function; The connection between the motor winding and the bridge arm is as follows: The A-phase winding of the No. 1 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 respectively connected in series with the C-phase bridge arms of the four motors, and are triggered to conduct when a corresponding bridge arm fault is detected to form a new current path, thereby achieving fault-tolerant operation; The fault-tolerant control strategy includes: when an open circuit or short circuit fault is detected in the C-phase bridge arm, the system controller automatically turns off the power switch of the faulty bridge arm and activates the corresponding bidirectional thyristor to allow the motor to continue to work normally; The four-motor fault-tolerant working topology adopts a centralized control method, and the system controller can adjust the fault-tolerant strategy according to the real-time operating status to improve the stability and reliability of the system.

2. The four-motor fault-tolerant working topology structure according to claim 1, characterized in that: The motor combination with open circuit failure is one of motor No. 1, motor No. 2, and motor No. 3; motor No. 1, motor No. 2, and motor No. 4; motor No. 1, motor No. 3, and motor No. 4; and motor No. 2, motor No. 3, and motor No.

4. The C-phase winding of the faulty motor is connected to the ninth-phase bridge arm, and the control effect of each motor is considered and the duty cycle is allocated to stabilize the fault-tolerant control effect of the motor group.

3. The four-motor fault-tolerant working topology structure according to claim 1, characterized in that: The first phase bridge arm includes a first phase upper bridge arm power switch device T1 and a first phase lower bridge arm power switch device T2, the second phase bridge arm includes a second phase upper bridge arm power switch device T3 and a second phase lower bridge arm power switch device T4, the third phase bridge arm includes a third phase upper bridge arm power switch device T5 and a third phase lower bridge arm power switch device T6, the fourth phase bridge arm includes a fourth phase upper bridge arm power switch device T7 and a fourth phase lower bridge arm power switch device T8, the fifth phase bridge arm includes a fifth phase upper bridge arm power switch device T9 and a fifth phase lower bridge arm power switch device T10, the sixth phase bridge arm includes a sixth phase upper bridge arm power switch device T11 and a sixth phase lower bridge arm power switch device T12, and the seventh phase bridge arm includes The seventh-phase upper bridge arm power switch device T13 and the seventh-phase lower bridge arm power switch device T14, the eighth-phase bridge arm includes the eighth-phase upper bridge arm power switch device T15 and the eighth-phase lower bridge arm power switch device T16, the ninth-phase bridge arm includes the ninth-phase upper bridge arm power switch device T17 and the ninth-phase lower bridge arm power switch device T18, the tenth-phase bridge arm includes the tenth-phase upper bridge arm power switch device T19 and the tenth-phase lower bridge arm power switch device T20, the eleventh-phase bridge arm includes the eleventh-phase upper bridge arm power switch device T21 and the eleventh-phase lower bridge arm power switch device T22, and the twelfth-phase bridge arm includes the twelfth-phase upper bridge arm power switch device T23 and the twelfth-phase lower bridge arm power switch device T24.

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

5. The four-motor fault-tolerant working topology structure according to claim 1, characterized in that: The lower node of the first-phase upper bridge arm power switch device T1 and the upper node of the first-phase lower bridge arm power switch device T2 are connected as the output node of the first-phase bridge arm; the lower node of the second-phase upper bridge arm power switch device T3 and the upper node of the second-phase lower bridge arm power switch device T4 are used as the output node of the second-phase bridge arm; the lower node of the third-phase upper bridge arm power switch device T5 and the upper node of the third-phase lower bridge arm power switch device T6 are used as the output node of the third-phase bridge arm; the lower node of the fourth-phase upper bridge arm power switch device T7 and the upper node of the fourth-phase lower bridge arm power switch device T8 are used as the output node of the fourth-phase bridge arm; the lower node of the fifth-phase upper bridge arm power switch device T9 and the upper node of the fifth-phase lower bridge arm power switch The upper node of the device T10 is used as the output node of the fifth phase bridge arm; the lower node of the sixth phase upper bridge arm power switch device T11 and the upper node of the sixth phase lower bridge arm power switch device T12 are used as the output node of the sixth phase bridge arm; the lower node of the seventh phase upper bridge arm power switch device T13 and the upper node of the seventh phase lower bridge arm power switch device T14 are used as the output node of the seventh phase bridge arm; the lower node of the eighth phase upper bridge arm power switch device T15 and the upper node of the eighth phase lower bridge arm power switch device T16 are used as the output node of the eighth phase bridge arm; the lower node of the ninth phase upper bridge arm power switch device T17 and the upper node of the ninth phase lower bridge arm power switch device T18 are used as the output node of the ninth phase bridge arm; The lower node of the tenth-phase upper bridge arm power switch device T19 and the upper node of the tenth-phase lower bridge arm power switch device T20 serve as the output node of the tenth-phase bridge arm; the lower node of the eleventh-phase upper bridge arm power switch device T21 and the upper node of the eleventh-phase lower bridge arm power switch device T22 serve as the output node of the eleventh-phase bridge arm; the lower node of the twelfth-phase upper bridge arm power switch device T23 and the upper node of the twelfth-phase lower bridge arm power switch device T24 serve as the output node of the twelfth-phase bridge arm.

6. A four-motor fault-tolerant working topology control method, characterized in that: The following steps are involved: S1: Connect the A-phase, B-phase and C-phase windings of the No. 1 motor, the No. 2 motor, the No. 3 motor and the No. 4 motor to the corresponding bridge arms of the twelve-phase bridge arms respectively, and connect the C-phase winding to the ninth-phase bridge arm through a bidirectional thyristor; S2: When an open circuit fault is detected in the motor combination, the C-phase winding of the faulty motor is reconfigured to the ninth-phase bridge arm to ensure that the system can continue to operate with fault tolerance; S3: Dynamically adjust the duty cycle according to the load status of each motor and the impact of the faulty motor to achieve balanced operation under fault conditions; S4: Optimize bridge arm power distribution and maintain system stability and efficiency by real-time monitoring of bridge arm current and voltage.

7. The four-motor fault-tolerant working topology control method according to claim 6, characterized in that: Specifically include the steps of dynamically allocating duty cycle: Identify faulty motor combinations through a fault detection module; According to the load demand of the non-faulty motor, the PWM waveform of the corresponding bridge arm is adjusted to maximize the operating efficiency of the motor group; The duty cycle is adjusted in real time using the feedback control mechanism to ensure current balance in each motor winding and prevent secondary faults caused by overload of a single bridge arm.

8. The four-motor fault-tolerant working topology control method according to claim 6, characterized in that: The following steps are included for bridge arm fault detection and processing: S1: Perform real-time current monitoring on the upper bridge arm power switch device and the lower bridge arm power switch device of each bridge arm; S2: If an abnormal drop in the bridge arm current is detected, it is determined to be an open circuit fault; S3: through logical judgment, select to reallocate the C-phase winding of the faulty motor to the ninth-phase bridge arm, and enable the bidirectional thyristor for conduction control; S4: After reallocation, the control parameters of the system are updated to adapt to the new bridge arm configuration.

9. The four-motor fault-tolerant working topology control method according to claim 6, characterized in that: The following steps are included to dynamically adjust the operating state of the bridge arm: S1: Adjust the output duty cycle of the non-fault bridge arm according to the real-time load requirements to optimize the output current distribution; S2: For the bridge arm to which the C-phase winding is reconnected, the priority scheduling algorithm is used 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 operating efficiency and control accuracy.

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