A Novel High Power Density Asynchronous Motor Adjustable Speed Drive System Design

The study and applications of high power density motor (HPDM) have received more attentions urgently by motion control experts. This paper discusses a drive method used to a kind of special high power density asynchronous motor, which we designed and its power density is more than 1.6 kW/kg. But its frequency conversion adjustable speed drives (ASDs) has particularity, such as: high output torque, harmonic, common-mode voltage, current distorted and loss factor etc. Harmonic can result in the calorific severity of HPDM. The ac/dc/ac conversion system used to provide ac voltages with adjustable frequency in the ASD, consists of a voltage source inverter (VSI). The design adopted an inverter output Passive Filter on drive inverter's hardware structure, and introduced a sort of Over-modulation algorithm for Space Vector PWM, which is proposed on inverter's software control. It is shown that the proposed approach can achieve the characteristic demands of ASD used to HPDM.