Fault-tolerant operation method in PMSM turn-to-turn short circuit fault state

Abstract

The invention discloses a fault-tolerant operation method in a turn-to-turn short-circuit fault state of a PMSM (permanent magnet synchronous motor). The fault-tolerant operation method comprises the following steps: establishing a short-circuit circulating current model and an electromagnetic torque model of the PMSM in the turn-to-turn short-circuit fault state in a synchronous rotating coordinate system; based on a short-circuit circulating current model and an electromagnetic torque model, a plurality of types of fault-tolerant operation points on the dq current plane are obtained under the constraint conditions that the short-circuit circulating current is controlled not to exceed a preset allowable value and the output torque is maximized under the condition that the output torque does not exceed the pre-fault level; based on the voltage information, the current information and the rotating speed information of the PMSM in the turn-to-turn short-circuit fault state, the number of short-circuit turns Nf and the short-circuit point resistance rf during the turn-to-turn short-circuit fault are obtained; and selecting a corresponding fault-tolerant operation point from the plurality of fault-tolerant operation points according to the short-circuit turn number Nf, the short-circuit point resistance rf, the current rotating speed information and the current torque information of the PMSM in the turn-to-turn short-circuit fault state and a pre-established motor parameter query table.

Description

technical field [0001] The present specification relates to the technical field of motor control, and in particular, to a fault-tolerant operation method in a PMSM inter-turn short-circuit fault state. Background technique [0002] Among the many failure modes of PMSM drive systems, the inter-turn short-circuit fault of the stator winding caused by the degradation of the inter-turn insulation is one of the most common failure modes. The inter-turn short circuit is a gradual fault, but when proper fault-tolerant control is not applied, the short-circuit circulating current of the fault loop will also increase in a short time, thereby damaging the motor and threatening the safety of the system and personnel. [0003] In general motor drive applications, after a short-circuit fault between turns of the stator is detected, the adverse effects of the fault can be eliminated by direct shutdown. However, in situations with high safety requirements, the sudden shutdown of the motor...

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Problems solved by technology

However, in occasions with high safety requirements, the sudden shutdown of the motor drive system may cause serious accidents. Therefore, even if the motor has a stator turn-to-turn short circuit fault, it must be ensured that the motor can output torque, at least until it can be safely stopped.

At present, the research on fault-tolerant control of PMSM stator turn-to-turn short-circuit fault mainly focuses on multi-phase motors and three-phase motor drive systems with complex inverter structures. The fault-tolerant control methods or fault-tolerant operation methods are not suitable for traditional three-phase PMSM drive systems.

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