Fault-tolerant Field Oriented Control Method for Five-phase Permanent Magnet Linear Motor

Abstract

The invention discloses an adjacent two phase short-circuit fault-tolerant filed-oriented control method for a five-phase permanent magnet embedded fault-tolerant linear motor. The method comprises the steps of solving fault-tolerant current of healthy phases according to principles that traveling waves are constant in magnetomotive force before and after a fault and the sum of healthy-phase current is zero; transforming a nonlinear strong-coupling system of the type of motor at a fault state into a one-order inertia system by adopting an internal model controller, a one-order inertia feedforward voltage compensator and a counter potential observer; solving a healthy-phase voltage command on the basis, adding the voltage command to the counter potential of each phase so as to realize fault-tolerant field-oriented control after an adjacent two phase short-circuit fault of the motor. The method disclosed by the invention not only suppresses motor output thrust ripples caused by the adjacent two phase short-circuit fault of the motor, but also can realize fault-tolerant running of a fault that one of the two adjacent phases is open-circuit and the other phase is short-circuit. More importantly, the dynamic performance and the steady-state performance are consistent with the performance at a normal state, the switching frequency of a voltage source inverter is constant, and certain universality is provided.

Description

technical field [0001] The invention relates to a fault-tolerant control method for adjacent two-phase short-circuit faults of a five-phase permanent magnet motor, in particular to a fault-tolerant magnetic field oriented control method for adjacent two-phase short-circuit faults of a five-phase fault-tolerant permanent magnet linear motor. It is suitable for occasions that have high requirements on the reliability and dynamic performance of the motor, such as aerospace, electric vehicles, deep sea, and medical equipment. Background technique [0002] With the development of society and the improvement of people's living standards, the requirements for the comfort, safety and stability of car driving are getting higher and higher. As an important part of modern automobiles, the performance of the suspension system has an extremely important impact on the ride comfort and operational stability of the vehicle. Therefore, the research on active suspension systems has been highl...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies in the existing motor fault-tolerant control technology, according to the characteristics of the five-phase permanent magnet embedded fault-tolerant linear motor and the characteristics of the adjacent two-phase short-circuit fault of this type of motor, the purpose of the present invention is to overcome the short-circuit fault of the adjacent two-phase motor. The existing fault-tolerant strategy uses current hysteresis control to cause disordered switching frequency of the inverter, decreased motor response speed, poor dynamic performance, inability to accurately follow the current, and severe noise. The traditional current PI control is caused by the contradiction between rapid response and overshoot. The problem of difficult parameter adjustment, and the fact that the existing fault-tolerant vector control strategy cannot realize the fault-tolerant operation of the two-phase short-circuit fault situation, a kind of adjacent two-phase short-circuit fault-tolerant rotor for the five-phase permanent magnet embedded fault-tolerant linear motor of the present invention is proposed The field-oriented control method realizes the accurate estimation of the back EMF, reduces the difficulty of controller parameter adjustment, realizes high fault tolerance performance, high dynamic performance, and good current followability of this type of motor system in the state of adjacent two-phase short-circuit faults, and reduces CPU overhead, to achieve constant switching frequency of the inverter, reduce noise, and then improve the dynamic performance and reliability of the five-phase permanent magnet embedded fault-tolerant linear motor of the present invention under the condition of adjacent two-phase short-circuit faults

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