A current-fed hf link direct DC/AC converter with active harmonic filter for fuel cell power systems

Abstract

This paper describes a current-fed high frequency (HF) link direct DC/AC converter suitable for fuel cell power source. The proposed current-fed HF link direct DC/AC converter consists of a current-fed full-bridge inverter with an active harmonic filter, a HF link transformer, and a simple cycloconverter. The high frequency full-bridge inverter at the primary generates sinusoidally PWM modulated current pulses with zero current switching (ZCS), and the cycloconverter at the secondary which consists of only two bidirectional switches and output filter capacitors produces sinusoidally modulated 60 Hz split single phase output voltage waveforms with near zero current switching. An optional active harmonic filter connected to the input terminal compensates the low order input current harmonics drawn from the fuel cell without long-term energy storage devices such as batteries and super capacitors. The basic concept and operation of the proposed current-fed HF link DC/AC converter and active harmonic filter are presented. The various simulation results are provided to verify the feasibility of the proposed DC/AC converter.