System for improving average torque under fault-tolerant control of double three-phase motors and application

Abstract

The invention relates to the field of permanent magnet synchronous motor control, and discloses a system for improving average torque under fault-tolerant control of double three-phase motors and application, the system comprises a six-phase eight-bridge-arm inverter, and a first bridge arm n and a second bridge arm n are newly added on the basis of a standard six-phase six-bridge-arm topology; the output end of the first bridge arm n is connected with a neutral point N of a first set of three-phase windings of the dual-three-phase motor, and the output end of the second bridge arm n is connected with a neutral point N of a second set of three-phase windings; and the control unit is configured to inject a zero input voltage signal into the newly added first bridge arm n and the second bridge arm n, and generate a bridge arm driving signal by comparing the zero input voltage signal with a triangular modulation wave. The method can solve the problems of overlarge average torque attenuation or capacitor voltage fluctuation, high system current harmonic rate and low direct current utilization rate during fault-tolerant control of an existing dual three-phase motor fault-tolerant control system.

Description

Technical Field

[0001] The present application relates to the field of permanent magnet synchronous motor control, and more specifically, to a system and application for improving average torque under fault-tolerant control of dual three-phase motors. Background Art

[0002] Due to their high power density and excellent fault tolerance, dual three-phase motors are widely used in electric vehicles and aviation. Based on the principle of constant total magnetomotive force, when the phase current is in sinusoidal mode, the maximum average torque that can be achieved by a dual three-phase motor with a dual neutral point structure during fault-tolerant operation with a single phase loss is 57.74% of the original torque. To address the issue of excessive average torque attenuation during fault-tolerant control of dual three-phase motors with a single phase loss, relevant literature has proposed connecting the neutral points of the motor's two sets of three-phase windings to the neutral point of the DC power supply capacitor (i.e., a split capacitor structure) to remove the constraints imposed by the original structure and thereby increase the motor's average torque under fault-tolerant control. However, this strategy suffers from issues such as capacitor voltage fluctuations, high system current harmonics, and low DC utilization. Summary of the Invention

[0003] In response to at least one defect or improvement need in the prior art, the present invention provides a system and application for improving the average torque under fault-tolerant control of a dual three-phase motor, aiming to solve the problems of excessive average torque attenuation or capacitor voltage fluctuation, high system current harmonic rate, and low DC utilization rate in the neutral point connection method adopted in the existing dual three-phase motor fault-tolerant control system during fault-tolerant control.

[0004] To achieve the above-mentioned objectives, according to the first aspect of the present invention, a system for improving the average torque under fault-tolerant control of a dual three-phase motor is provided, comprising: a six-phase eight-bridge-arm inverter, in which a first bridge arm n1 and a second bridge arm n2 are newly added on the basis of a standard six-phase six-bridge-arm topology; the output end of the first bridge arm n1 is connected to the neutral point N1 of the first set of three-phase windings of the dual three-phase motor, and the output end of the second bridge arm n2 is connected to the neutral point N2 of the second set of three-phase windings; a control unit is configured to inject a zero input voltage signal into the newly added first bridge arm n1 and second bridge arm n2, and generate a bridge arm drive signal by comparing with a triangular modulation wave.

[0005] In one embodiment of the present invention, the control unit performs the following steps: controlling the first bridge arm n1 to make its current in1=−(iA+iB+iC) The control target of the second bridge arm n2 is to make its current in2=−(iD+iE+iF) ,in, iA ~ iF is the current of each phase winding.

[0006] In one embodiment of the present invention, the control unit adopts a closed-loop control strategy, including: calculating the actual neutral point current of the first bridge arm n1 and the second bridge arm n2 ing 1=−( iA + iB + iC )and ing 2=−( iD + iE + iF ) The difference between the target current and the actual current is input into the PI controller to generate a modulation signal.

[0007] In one embodiment of the present invention, the closed-loop control is simplified to a modulation structure in which zero input voltage is directly compared with a triangular modulation wave, so that the duty cycle functions of the newly added first bridge arm n1 and second bridge arm n2 satisfy: dn 1= dn 2=0.5; where dn 1 is the duty cycle of the first bridge arm n1, dn 2 is the duty cycle of the second bridge arm n2.

[0008] In one embodiment of the present invention, the fundamental wave content in the duty cycle of the newly added first bridge arm n1 and second bridge arm n2 is expressed as: ;in, i Number the bridge arms.

[0009] In one embodiment of the present invention, the frequency of the triangular modulation wave is consistent with a standard six-phase modulation carrier, and the amplitude range covers a zero input voltage signal.

[0010] In one embodiment of the present invention, the system for increasing average torque under fault-tolerant control of dual three-phase motors triggers a fault-tolerant control mode upon detecting a single-phase open circuit fault, including: maintaining the maximum current amplitudes of the remaining five phases the same as before the fault; and removing the current constraint of the double neutral point structure by adding the first bridge arm n1 and the second bridge arm n2. iA + iB + iC = 0 and iD + iE + iF= 0.

[0011] According to a second aspect of the present invention, a fault-tolerant control method for a dual three-phase motor based on the system described in any of the above embodiments is provided, comprising the following steps: upon detecting a single-phase open-circuit fault, switching to a six-phase, eight-bridge-leg drive mode; injecting a zero-voltage reference signal into the newly added bridge leg to generate a PWM wave with a duty cycle of 0.5; and controlling the currents of the remaining five phases to maintain the total magnetomotive force consistent with that before the fault.

[0012] In one embodiment of the present invention, the post-fault fault-tolerant control satisfies: the maximum current amplitude of each phase does not exceed the pre-fault limit; and the voltage clamping of the neutral points of the two sets of windings to the midpoint of the DC bus is achieved by adding a bridge arm.

[0013] According to the third aspect of the present invention, a computer-readable storage medium is also provided, which stores a computer program that can be executed by an access authentication device. When the computer program runs on the access authentication device, the access authentication device executes the dual three-phase motor fault-tolerant control method described in any one of the above embodiments.

[0014] In general, the above technical solutions conceived by the present invention can achieve at least the following beneficial effects compared with the prior art: The system for improving the average torque under fault-tolerant control of dual three-phase motors proposed in the present invention analyzes the maximum average torque that can be achieved before and after the current constraints are lifted when the dual three-phase motors are operating in fault-tolerant mode under a single-phase open circuit. A six-phase eight-bridge-leg inverter structure is adopted, and the working principle and modulation algorithm of the structure are analyzed to meet the requirements of lifting the constraints on phase current of the double neutral point structure, thereby greatly improving the average torque of the motor during fault-tolerant operation under a single-phase open circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic diagram of the structure of a system for improving average torque under fault-tolerant control of dual three-phase motors provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of two neutral point connection methods for dual three-phase motors provided in an embodiment of the present application; Figure 3 A schematic diagram of the average large signal model structure of a six-phase eight-leg inverter provided in an embodiment of the present application; Figure 4 A schematic diagram of the zero-sequence current control circuit structure provided in an embodiment of the present application; Figure 5 Schematic diagram of the fault-tolerant control effect under two neutral point connection modes provided in the embodiments of the present application; Figure 6 A flow chart of a dual three-phase motor fault-tolerant control method provided in an embodiment of the present application; Figure 7 A schematic diagram of a computer-readable storage medium provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0018] The terms "first," "second," "third," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0019] like Figure 1 As shown, the first embodiment of the present invention proposes a system for improving the average torque under fault-tolerant control of dual three-phase motors, adopting a driving structure of a six-phase eight-bridge-arm inverter. Compared with the existing six-phase six-bridge-arm inverter structure, two new bridge arms n1 and n2 are added, which are respectively connected to the neutral points N1 and N2 of the two sets of three-phase windings to realize the circulation of neutral point current of the two sets of windings.

[0020] The following first analyzes and explains the dual three-phase motor fault-tolerant control system of the existing six-phase six-leg inverter. The dual neutral point method can effectively suppress zero-sequence current and reduce two current controllers. Therefore, the dual neutral point method is often used during normal operation of the dual three-phase permanent magnet synchronous motor. Other neutral point connection methods can achieve better performance during fault-tolerant operation due to the reduction of constraints. Among them, the structure with the best performance is the structure that connects the neutral points of the two sets of three-phase windings of the motor to the neutral point of the DC power supply capacitor. The two structures are represented by neutral point connection method 1 and neutral point connection method 2, respectively. Figure 2 shown.

[0021] According to Kirchhoff's current law, the neutral point connection method 1 has a current constraint as shown in formula (1), which does not exist in the neutral point connection method 2.

[0022] (1) In a dual three-phase permanent magnet synchronous motor, electromagnetic torque can be considered the result of the interaction between the rotating magnetomotive force of the winding current in the air gap and the magnetomotive force of the permanent magnet. Therefore, it is only necessary to ensure that the magnetic force generated by the residual phase current after the motor loses a phase remains the same as before the phase loss to maintain normal operation of the motor. The total magnetomotive force of the stator of a dual three-phase permanent magnet synchronous motor can be expressed as: (2) When the dual three-phase motor is in normal operation, the current of each phase is: (3) Substituting equation (3) into equation (2), the total magnetic potential of the dual three-phase motor during normal operation is: (4) When the motor has an open circuit fault in phase F, i F =0. Comparing Equations (2) and (4), in order to obtain the same stator synthetic magnetomotive force, the remaining five-phase currents must satisfy the conditions shown in Equation (5).

[0023] (5) The current of each phase maintains a sinusoidal mode, and the current of each phase can be expressed as shown in the formula.

[0024] (6) Substituting equation (6) into equation (5) and separating the real and imaginary parts, we can get (7) Since there are a total of 10 unknown variables, neutral point connection method 1 has two sets of constraints, equations (1) and (7), that is, 8 constraints, and neutral point connection method 2 has only one set of constraints, equation (7), that is, 4 constraints. Therefore, both structural equations have no unique solution. In research, the above equations are often used as constraints, and a certain performance indicator is used as the optimization target to find a set of optimal solutions through continuous optimization.

[0025] In practical applications, there are often two optimization indicators: one is to minimize the stator current amplitude, that is, the maximum torque output, and the other is to minimize the stator copper loss, that is, the minimum copper loss. The former optimal goal is to minimize the current amplitude as much as possible, which is beneficial to the design of the inverter and reduces the average torque attenuation caused by open circuit faults. Therefore, this embodiment takes the maximum torque output as the optimal goal. Its performance index can be expressed by the maximum value of the current amplitude of each phase, as shown in formula (8). The purpose of optimization is to find the value that makes The smallest set of solutions.

[0026] (8) For example, through numerical calculations using MATLAB software, we can obtain the solutions for two neutral point connection methods with maximum torque output as the optimal goal, as shown below.

[0027] Neutral point connection method 1: (9) Neutral point connection method 2: (10) Since the motor uses i d =0 control, the current amplitude of each phase is q The shaft currents are equal, that is, the current amplitude of each phase is linearly related to the electromagnetic torque. When the motor speed remains unchanged, the current amplitude of each phase is linearly related to the average torque of the motor. In order to ensure the normal operation of the switching device, the maximum current amplitude of each phase is kept unchanged before and after the phase failure. Therefore, the maximum torque that can be achieved after the phase failure of the neutral point connection method 1 is 1 / 2 of the original torque. times, that is, 0.577 times, and the maximum torque that can be achieved after the neutral point connection method 2 is missing is the original torque times, that is 0.806 times.

[0028] As can be seen from the above, neutral point connection mode 2 removes the voltage constraint shown in formula (1), thereby increasing the average torque of the motor from 57.7% of the original torque to 80.6% during fault-tolerant operation under single-phase fault. However, neutral point connection mode 2 has problems such as capacitor voltage fluctuation and low DC utilization.

[0029] In order to effectively solve the problems caused by the split capacitor structure, this embodiment proposes an equivalent six-phase eight-bridge-leg inverter driving structure, such as Figure 1 As shown in .

[0030] First, define the duty cycle function of each phase bridge arm as: (11) Since only the fundamental content in the duty cycle is analyzed, the harmonic components caused by pulse width modulation are ignored. d i Available expression, for the convenience of analysis, the subsequent express d i The amount of communication.

[0031] (12) like Figure 3 As shown, the average signal model of the circuit structure in 1 can be obtained according to the bridge arm average modeling method.

[0032] Among them, the DC side current i pand i n Expressed as: (13) (14) Since the DC side voltage midpoint is suspended, the following constraints exist: (15) Substituting equations (13) and (14) into equation (15), we can obtain (16) Splitting equation (16) into two equations, we can get (17) By adding bridge arms n1 and n2 through current loop control to make equation (17) valid, the current constraint shown in equation (1) can be released.

[0033] The control of bridge arms n1 and n2 is actually to control the opening and closing of the upper and lower bridge arms of the two bridge arms. i n1 、 i n2 Track the negative sum of the two sets of three-phase winding currents. According to Kirchhoff's current law, we can get i n1 、 i n2 The actual value of 、 for: (18) Comparing formula (17) and formula (18), we can find that i ng1 、 i ng2 The given value is the same as the actual value, so the value after subtracting the two and passing through the PI controller is still 0, so the control circuit can be simplified to Figure 4 The structure shown.

[0034] according to Figure 4 The structure shown controls the newly added bridge arms n1 and n2. Since the input comparison voltage is 0, the AC component in the duty cycle bridge arm is 0. The duty cycle function of the newly added bridge arm is: (19) Under this duty cycle function, the average large signal model voltage of the two bridge arms is , that is, the voltage clamping of the neutral point of the DC power supply by the neutral points N1 and N2 of the two sets of windings is realized. Therefore, the six-phase eight-leg inverter structure under this control structure has the same control effect as the neutral point connection mode 2.

[0035] In order to verify the validity of the theoretical derivation, this embodiment builds simulation models according to the neutral point connection mode 1 and the six-phase eight-bridge-leg inverter structure respectively. The motor operates under fault-tolerant control under the F-phase open circuit condition. The maximum phase current amplitude and motor speed are kept unchanged before and after fault-tolerant control. The average output torque of the motor under the two structures is compared. The results are as follows: Figure 5 shown.

[0036] from Figure 5 It can be seen that while keeping the current amplitude and speed unchanged before and after the fault, the six-phase eight-leg inverter drive structure can increase the electromagnetic torque under fault-tolerant control from 0.577 times the rated torque of the original structure to 0.806 times the rated torque.

[0037] To sum up, the first embodiment of the present invention proposes a system for improving the average torque of a dual three-phase motor under fault-tolerant control. By analyzing the maximum average torque that can be achieved before and after the current constraint is released when the dual three-phase motor is performing fault-tolerant operation under a single-phase open circuit, a six-phase eight-bridge-arm inverter structure is adopted, and the working principle and modulation algorithm of the structure are analyzed to meet the requirements of releasing the constraints of the double neutral point structure on the phase current, thereby greatly improving the average torque of the motor during fault-tolerant operation under a single-phase open circuit.

[0038] In addition, if Figure 6 As shown, the second embodiment of the present invention proposes a dual three-phase motor fault-tolerant control method based on the system described in the first embodiment, for example, including: step S1, when a single-phase open circuit fault is detected, switching to a six-phase eight-bridge arm drive mode; injecting a zero voltage reference signal into the newly added bridge arm to generate a PWM wave with a duty cycle of 0.5; controlling the remaining five-phase current to maintain the total magnetomotive force consistent with that before the fault.

[0039] In one embodiment, the fault-tolerant control after the system fault satisfies: the maximum current amplitude of each phase does not exceed the pre-fault limit; and the voltage clamping of the neutral points of the two sets of windings to the midpoint of the DC bus is achieved through the newly added bridge arms.

[0040] It should be noted that the dual three-phase motor fault-tolerant control method disclosed in the second embodiment of the present invention is implemented by the system for improving the average torque under the dual three-phase motor fault-tolerant control described in the aforementioned first embodiment. The specific system structure and the functions it implements can refer to the contents described in the first embodiment and will not be described in detail here. The beneficial effects of the dual three-phase motor fault-tolerant control method proposed in this embodiment are the same as those of the aforementioned first embodiment. For the sake of brevity, they will not be repeated here.

[0041] like Figure 7As shown, the third embodiment of the present application also provides a computer readable storage medium 40, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above method. The computer readable storage medium 40 provided by the embodiment has the same beneficial effects as the average torque improvement method based on the fault-tolerant control of the dual three-phase motor provided by the first embodiment.

[0042] The computer readable storage medium can include, but is not limited to, any type of disk including floppy disks, optical disks, DVD, CD-ROMs, micro-drives, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nano-systems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0043] It should be noted that, for the foregoing method embodiments, in order to simply describe, they are all described as a series of action combinations, but those skilled in the art should know that the present application is not limited to the order of the actions described, because according to the present application, certain steps can be performed in other order or at the same time. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0044] In the above embodiments, the description of each embodiment is focused on, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0045] In the several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic. The division of the units is only a logical function division. There can be another division manner for actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some services interfaces, devices or units, and can be electrical or other forms.

[0046] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment.

[0047] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0048] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk, or optical disk, etc., various media that can store program code.

[0049] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructing related hardware through a program. The program may be stored in a computer-readable memory, which may include a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0050] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0051] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for increasing average torque under fault-tolerant control of dual three-phase motors, characterized in that: include: Six-phase eight-leg inverter, which adds the first leg (n1) and second leg (n2) to the standard six-phase six-leg topology; The output end of the first bridge arm (n1) is connected to the neutral point (N1) of the first set of three-phase windings of the dual three-phase motor, and the output end of the second bridge arm (n2) is connected to the neutral point (N2) of the second set of three-phase windings; The control unit is configured to inject a zero input voltage signal into the newly added first bridge arm (n1) and the second bridge arm (n2), and generate a bridge arm driving signal by comparing with the triangular modulation wave.

2. The system for improving average torque under fault-tolerant control of dual three-phase motors according to claim 1, characterized in that: The control unit performs: The control target of the first bridge arm (n1) is to make its current in1=−(iA+iB+iC) ; The control target of the second bridge arm (n2) is to make its current in2=−(iD+iE+iF) ,in, iA ~ iF is the current of each phase winding.

3. The system for improving average torque under fault-tolerant control of dual three-phase motors according to claim 2, characterized in that: The control unit adopts a closed-loop control strategy, including: Calculate the actual neutral point current of the first bridge arm (n1) and the second bridge arm (n2) ing 1=−( iA + iB + iC )and ing 2=−( iD + iE + iF ); The difference between the target current and the actual current is input into the PI controller to generate a modulation signal.

4. The system for improving average torque under fault-tolerant control of dual three-phase motors according to claim 3, characterized in that: The closed-loop control is simplified to a modulation structure in which zero input voltage is directly compared with a triangular modulation wave, so that the duty cycle functions of the newly added first bridge arm (n1) and the second bridge arm (n2) satisfy: dn 1= dn 2=0.5； in, dn 1 is the duty cycle of the first bridge arm (n1), dn 2 is the duty cycle of the second bridge arm (n2).

5. The system for improving average torque under fault-tolerant control of dual three-phase motors according to claim 1, characterized in that: The fundamental wave content in the duty cycle of the newly added first bridge arm (n1) and the second bridge arm (n2) is expressed as: ； in, i Number the bridge arms.

6. The system for increasing average torque under fault-tolerant control of dual three-phase motors according to claim 1, characterized in that: The frequency of the triangular modulation wave is consistent with the standard six-phase modulation carrier, and the amplitude range covers the zero input voltage signal.

7. The system for increasing average torque under fault-tolerant control of dual three-phase motors according to claim 1, characterized in that: Triggering fault-tolerant control mode when a single-phase open circuit fault is detected, including: Maintain the maximum current amplitudes of the remaining five phases to be the same as before the fault; The current constraint of the double neutral point structure is released by the newly added first bridge arm (n1) and second bridge arm (n2): iA + iB + iC= 0 and iD + iE + iF= 0.

8. A dual three-phase motor fault-tolerant control method based on the system of any one of claims 1-8, characterized in that: Including steps: When a single-phase open circuit fault is detected, it switches to the six-phase eight-bridge arm drive mode; Inject a zero voltage reference signal into the newly added bridge arm to generate a PWM wave with a duty cycle of 0.5; Control the remaining five-phase currents to maintain the total magnetomotive force consistent with that before the fault.

9. The dual three-phase motor fault-tolerant control method according to claim 8, characterized in that: The fault-tolerant control after the failure satisfies: The maximum current amplitude of each phase does not exceed the pre-fault limit; The voltage of the neutral points of the two windings to the midpoint of the DC bus is clamped by adding a bridge arm.

10. A computer-readable storage medium storing a computer program executable by an access authentication device, wherein when the computer program is run on the access authentication device, the access authentication device executes the steps of the dual three-phase motor fault-tolerant control method according to any one of claims 8 to 9.

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