Method for suppressing rotational speed and torque ripple of PMSM under three-phase asymmetric fault

Abstract

The invention discloses a method for suppressing the rotational speed and torque ripple of a permanent magnet synchronous motor under a three-phase asymmetric fault. According to the characteristics of the rotational speed and torque periodic pulsation oscillation under the fault state, an iterative learning controller based on a rotor position is designed, a closed-loop iterative learning law with a forgetting factor is constructed, and the convergence analysis of the iterative learning controller is performed. By periodically compensating a cross-axis reference current iqref, the rotationalspeed and torque closely follow given values. The method of the invention is applied to the constant speed operation of the motor in the fault state and also has a good suppression effect on the periodic oscillation of the rotational speed and the torque during a shifting operation.

Description

technical field [0001] The invention relates to the field of new energy vehicle motor drive, in particular to a method for suppressing rotational speed torque ripple of a permanent magnet synchronous motor under a three-phase asymmetrical fault. Background technique [0002] In recent years, with the deepening of people's understanding of the concept of environmental protection, governments of various countries have vigorously developed and supported new energy electric vehicles. Permanent Magnet Synchronous Motor (PMSM) is widely used in new energy vehicles due to its advantages of high torque density, high power density and high performance. When the permanent magnet synchronous motor has a three-phase asymmetric fault, the speed and torque will pulsate and oscillate, which will affect the safety of the vehicle, and even a tragedy that endangers personal safety will occur, resulting in irreparable and serious consequences. [0003] So far, the methods of speed and torque ...

AI Technical Summary

Problems solved by technology

When the permanent magnet synchronous motor has a three-phase asymmetric fault, the speed and torque will pulsate and oscillate, which will affect the safety of the vehicle, and even a tragedy that endangers personal safety will occur, resulting in irreparable and serious consequences

[0003] So far, the methods of speed and torque ripple suppression mainly focus on the mathematical model of the motor in a symmetrical state, and there is not much research and analysis on the motor with asymmetrical operation of the three-phase stator winding.

Moreover, the pulsation suppression of permanent magnet synchronous motors in the traditional sense is mainly based on the iterative learning control strategy (Iterative Learning Control, ILC) in the time domain, and its iteration period is generally proportional to the rotor rotation period, so it is limited to constant speed motion

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