A versatile power converter for high frequency link systems

The single-phase high frequency link appears to be an attractive alternative to the dc link commonly employed in power conversion systems. This paper proposes a power converter suitable for one-step conversion of the single-phase high frequency link voltage to the three-phase low frequency voltages typically required for interfacing with system sources and loads. The converter is utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique of pulse density modulation for the control of the amplitude, frequency and the waveshape of the synthesized low frequency signals. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or currents outputs is shown to be straight forward. The feasibility of the proposed power circuit and the control technique have been experimentally verified.