Control method for achieving high power factor in single-phase to three-phase converters without electrolytic capacitors

Abstract

In this paper, we propose a method for the digital control of IPM motors in order to achieve a high power factor in single-phase to three-phase power converters without reactors or electrolytic capacitors. For achieving the unity power factor under any load condition and any speed condition, we propose a new digital control method that involves the use of a new feedback technique and a new feedforward technique on the source-current regulator side. The proposed digital control system is constructed by using DSP devices. In this paper, we also propose a new method for the compensation of one sampling delay time. The superior performance of the proposed method is demonstrated by experimental results. The experimental results were obtained using 1.5 [kW] inverter system, which consists of a vector control system with a 14 [μF] dc-link capacitor. The maximum power factor obtained in the experiments was 96.8 [%]. © 2009 The Institute of Electrical Engineers of Japan.