Utility-interactive power conditioning system by using conventional forward converter with single high frequency switching device

Some papers of power converters that interface between photovoltaic arrays and a.c. utility system have been reported [1]–[3]. Some innovative utility-interactive power conditioning systems have been also studied [4],[5]. The characteristics of these systems lie in the fact that a full wave rectified current waveform is generated from the d.c. source and converted into a low distortion sinusoidal current which is fed inphase with the a.c. sinusoidal voltage of the utility. This method has various advantages, but the circuit configurations and control systems are a little complicated. However, as the cost of such systems will rise, it is preferable the utility interactive system without on-site battery. This paper proposes a simple utility interactive photovoltaic power conditioning system with a forward converter. In addition, innovative lossless snubber circuits are presented and discussed.