Overmodulation strategy for high-performance torque control

摘要

In the overmodulation region, the operation of the electricalndrive system with a current controller is characterized by a rapidndeterioration of motor torque and speed. It is desirable to use thenovermodulation strategy, which guarantees the fast response even inntransient state and satisfies the overall closed-loop controlnperformance. In this paper, in order to improve the dynamicncharacteristics of the electrical drive, a new overmodulation techniquenis proposed. Considering the current transition characteristics, annefficient overmodulation strategy is introduced to achieve betterntransient performance through an adequate voltage selection. With thenhelp of a new overmodulation strategy, required electrical torque can bendirectly produced as quickly as possible, and stable drivencharacteristics can be achieved in the transient condition. The proposednmethod has been implemented on an actual inverter system and thoroughlyntested on a 900-W interior permanent magnet synchronous machine (IPMSM)nto confirm its feasibility