Examination of the Output Characteristics for a Series Resonant DC Link PWM Inverter

Abstract

Recently, the soft-switching technique is used for the power conversion systems. This prevents the switching losses and EMI (electro-magnetic interference). Therefore, the authors had proposed a new series resonant dc link PWM (pulse width modulation) inverter. The prototype inverter had some merits that had small dc inductance and the output capacitors with fixed pulse frequency. However, the waveform of the output current was clamped at around zero with open loop control, and the voltage of the resonant capacitor had to be inverted. Because of these problems, the control became difficult. This paper proposes a series resonant dc link PWM inverter for the solution of these problems. The result of improvement, the control becomes easier, and the efficiency becomes higher than the prototype inverter. In this paper, the system, the operation, the experimental result, and the design of the improved inverter are explained.