A fault-tolerant operation method for multi-phase motors considering multiple degrees of freedom

Abstract

The invention discloses a phase-break fault-tolerant operation method of a multi-phase motor considering multiple degrees of freedom, and belongs to the technical field of multi-phase motor control. It mainly includes the calculation of fault-tolerant current reconstruction coefficient considering multiple degrees of freedom, the harmonic plane based on the symmetrical component method positive and negative sequence current decoupling controller and the fundamental wave plane vector control strategy. In addition to the basic constraints of maintaining the constant magnetomotive force before and after the fault, the current reconstruction calculation method uses the remaining degrees of freedom to constrain the injection current of the harmonic plane, in which the vector trajectory of the third harmonic plane is circular, and the vector trajectory of the residual harmonic plane is circular. The degrees of freedom are combined to optimize the solution to minimize copper loss; the harmonic plane adopts a dual PI current controller with positive and negative sequence decoupling, and the fundamental wave plane control method remains unchanged. The open-phase fault-tolerant operation method of the multi-phase motor disclosed by the present invention satisfies various indicators such as increasing torque, reducing torque ripple, and reducing copper loss in a balanced manner; while suppressing the tracking error of asymmetric current after a fault, it simplifies fault tolerance after a fault algorithm.

Description

technical field [0001] The invention relates to the technical field of multi-phase motor control, in particular to a multi-phase motor fault-tolerant operation method considering multiple degrees of freedom. Background technique [0002] Multi-phase motors have the characteristics of high reliability, high power density, rich control resources, and the ability to distribute power to each phase to achieve low voltage and high power. It is especially suitable for ships, multi-electric aircraft, electric vehicles, etc. that require high reliability. occasion. A three-phase motor cannot operate normally if a phase failure occurs without adding additional hardware, while a multi-phase motor can ensure smooth operation by reconstructing the phase current after a phase failure occurs. Therefore, a significant advantage of a multi-phase motor is that The reliability of the motor system. [0003] After a multi-phase motor fails, a reduced-order Clarke decoupling matrix can be used,...

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Problems solved by technology

However, the above three constraints are only optimized for a specific indicator, and there is no trade-off from a global perspective.

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