1707 / 2020-09-29 17:52:02

Stability Analysis and Improvement of an V/f controlled Induction Motor Drive Taking the Effect of Inverter Deadtime

deadtime compensation,system stability,light load,asynchronous machine,small signal model

Electric Machine Design and Control > Electric machine drives

Abstract--Asynchronous machine(AM) V/f control system suffer sustained oscillation in light load conditions. Both deadtime compensation(DCS) and constant excitation current control (CECC) system were proposed to suppress the system oscillation. However, DCS cannot suppress the oscillation in some hostile frequencies and the response is slow. And PI parameters of the CECC are difficult to confirm in the entire oscillation frequency. In this paper, the influence of different dead time on Asynchronous motor control system stability is discussed by establishing a small signal model of asynchronous motor including deadtime. And a method is proposed combined DCS with CECC, which can suppress the oscillation under light load and promote stator phase current harmonic performance. The simulation results based on an 7.5kW AM open-loop drive systems are presented to confirm the validity the proposed method.