CN-121984407-A - Fault tolerant operation of six phase motor

Abstract

A method of operating a multi-phase motor includes operating a six-phase motor having six phases configured as a first group having a first neutral connection and a second group having a second neutral connection. The method further includes determining whether at least one of the six phases is experiencing a fault. In response to the determination, the method includes combining the first neutral connection and the second neutral connection to form a common neutral connection to continue operation of the six-phase motor using the remaining phases that are not experiencing the fault.

Inventors

• A. Arafat
• D. S. morsi Baylor

Assignees

• 康明斯公司

Dates

Publication Date

20260505

Application Date

20200720

Priority Date

20190725

Claims (12)

1. 1. A method, the method comprising the steps of: Operating, by a controller, a six-phase motor having six phases configured into a first group having a first neutral connection and a second group having a second neutral connection; Determining, by the controller, whether at least one of the six phases is experiencing a fault, and In response to determining that at least one of the six phases is experiencing a fault, combining, by the controller, the first neutral connection and the second neutral connection to form a common neutral connection, thereby continuing operation of the six-phase motor with the remaining phases that are not experiencing the fault, Wherein the step of combining the first neutral connection and the second neutral connection comprises operating a switch to connect the first neutral connection and the second neutral connection to the common neutral connection, Wherein the step of using the remaining phases to operate the six-phase motor includes providing current to generate a Modified Magnetomotive Force (MMF) that approximates the MMF generated by the six-phase motor before the fault occurs.
2. 2. The method of claim 1, wherein the fault occurs in one of the first set of phases or one of the second set of phases and the step of using the remaining phases to operate the six-phase motor includes operating the six-phase motor as a five-phase motor.
3. 3. The method of claim 1 wherein the fault occurs in both one phase of the first set and one phase of the second set and the step of using the remaining phases to operate the six-phase motor includes operating the six-phase motor as a four-phase motor.
4. 4. The method of claim 1, further comprising the steps of detecting a fault condition causing the fault and generating a signal indicative of the fault condition.
5. 5. A controller, the controller comprising: processor, and A memory comprising instructions that, when executed by the processor, cause the controller to: Operating a six-phase motor having six phases configured into a first group having a first neutral connection and a second group having a second neutral connection; determining whether at least one of the six phases is experiencing a fault, and In response to determining that at least one of the six phases is experiencing a fault, combining the first neutral connection and the second neutral connection to form a common neutral connection to continue operation of the six-phase motor with the remaining phases not experiencing the fault, Wherein the instructions further cause the controller to operate a switch to connect the first neutral connection and the second neutral connection into the common neutral connection, Wherein the instructions, when executed by the processor, cause the controller to use the remaining phases to cause the six-phase motor to operate, further cause the controller to provide current to generate a Modified Magnetomotive Force (MMF) that approximates an MMF generated by the six-phase motor prior to the occurrence of the fault.
6. 6. The controller of claim 5, wherein the fault occurs in one phase of the first set or one phase of the second set and the instructions that when executed by the processor cause the controller to use the remaining phases to operate the six-phase motor further cause the controller to operate the six-phase motor as a five-phase motor.
7. 7. The controller of claim 5, wherein the fault occurs in both one phase of the first set and one phase of the second set, and the instructions that when executed by the processor cause the controller to use the remaining phases to operate the six-phase motor further cause the controller to operate the six-phase motor as a four-phase motor.
8. 8. The controller of claim 5, wherein the instructions, when executed by the processor, further cause the controller to detect a fault condition causing the fault and generate a signal indicative of the fault condition.
9. 9. A system, the system comprising: A six-phase motor having six phases configured into a first group having a first neutral connection and a second group having a second neutral connection; Switch and A controller coupled to the six-phase motor, the controller configured to: Operating the six-phase motor; determining whether at least one of the six phases is experiencing a fault, and In response to determining that at least one of the six phases is experiencing a fault, combining the first neutral connection and the second neutral connection to form a common neutral connection to continue operation of the six-phase motor with the remaining phases not experiencing the fault, Wherein the controller is configured to combine the first neutral connection and the second neutral connection by operating the switch to connect the first neutral connection and the second neutral connection into the common neutral connection, Wherein the controller is configured to generate a Modified Magnetomotive Force (MMF) by providing a current to operate the six-phase motor using the remaining phases, the modified magnetomotive force approximating the MMF generated by the six-phase motor before the fault occurs.
10. 10. The system of claim 9, wherein the fault occurs in one phase of the first set or one phase of the second set, and the controller is configured to operate the six-phase motor using the remaining phases by operating the six-phase motor as a five-phase motor.
11. 11. The system of claim 9, wherein the fault occurs in both one phase of the first set and one phase of the second set, and the controller is configured to operate the six-phase motor using the remaining phases by operating the six-phase motor as a four-phase motor.
12. 12. The system of claim 9, wherein the controller is further configured to detect a fault condition causing the fault and generate a signal indicative of the fault condition.

Description

Fault tolerant operation of six phase motor The application is a divisional application of the application patent application with the application date of 2020, 7-20, the application number of 202080047678.9 (International application number: PCT/US 2020/042770) and the application name of fault-tolerant operation of a six-phase motor. Cross Reference to Related Applications The present application claims priority from U.S. provisional patent application No. 62/878,421 filed on 7.25 2019 and entitled "FAULT TOLERANT OPERATIONS OF A SIX-PHASE MACHINE," the entire disclosure of which is expressly incorporated herein by reference. Technical Field The present disclosure relates generally to multi-phase motors and, more particularly, to techniques for controlling the operation of a six-phase motor (six-PHASE MACHINE) when one or more phases of the motor experience a fault or failure. Background Multiphase motors are used in a variety of applications including electric vehicles. For example, the drive system of an electric vehicle typically includes an Alternating Current (AC) motor driven by a Direct Current (DC) power source (e.g., a main battery). The AC motor is coupled to a DC power source via a power inverter that performs a switching function to convert DC power to AC power. One example of a multi-phase motor is a six-phase AC motor. In the event of failure of one or more phases of a six-phase AC motor, it is important to ensure that the remaining phases can still operate to provide the required torque/power. Accordingly, there remains a need to develop techniques for controlling the operation of a six-phase AC motor when one or more phases of the six-phase AC motor experience a fault/failure condition. Disclosure of Invention According to one embodiment, the present disclosure provides a method of operating a six-phase motor having six phases configured as a first group having a first neutral connection (neutral connection) and a second group having a second neutral connection by a controller. The method includes the step of determining whether at least one of the six phases is experiencing a fault. In response to determining that at least one of the six phases is experiencing a fault, the method includes combining the first neutral connection and the second neutral connection to form a common neutral connection to continue operation of the six-phase motor using the remaining phases that are not experiencing the fault. In one example, the step of combining the first neutral connection and the second neutral connection includes operating a switch to connect the first neutral connection and the second neutral connection into the common neutral connection. In another aspect, the fault occurs in one of the phases of the first or second group. Thus, the step of operating the six-phase motor by using the remaining phases includes operating the six-phase motor as a five-phase motor. In another aspect, the fault occurs in both one phase of the first set and one phase of the second set. Thus, the step of operating the six-phase motor by using the remaining phases includes operating the six-phase motor as a four-phase motor. In yet another aspect, the method includes detecting a fault condition causing a fault and generating a signal indicative of the fault condition. Further, the step of operating the six-phase motor by using the remaining phases includes providing current to generate a modified magnetomotive force that approximates the magnetomotive force generated by the six-phase motor prior to failure. According to another embodiment, the present disclosure provides a controller including a processor and a memory. The memory includes instructions that, when executed by the processor, cause the controller to operate a six-phase motor having six phases configured into a first group having a first neutral connection and a second group having a second neutral connection. The processor also causes the controller to determine whether at least one of the six phases is experiencing a fault. In response to determining that at least one of the six phases is experiencing a fault, the processor causes the controller to combine the first neutral connection and the second neutral connection to form a common neutral connection to continue operation of the six-phase motor by using the remaining phases that are not experiencing the fault. In one example, the step of combining the first neutral connection and the second neutral connection includes the processor causing the controller to operate the switch to connect the first neutral connection and the second neutral connection into a common neutral connection. In another aspect, the fault occurs in one of the phases of the first or second group. Thus, the processor causes the controller to operate the six-phase motor as a five-phase motor. In another aspect, the fault occurs in both one phase of the first set and one phase of the second set. Thus, the processor causes the cont