New soft switched interface circuit with reduced switch count for stand-alone photovoltaic systems

In this paper, a new soft switching bidirectional cuk converter is introduced which can be applied as the interface circuit between DC bus and batteries for stand-alone photovoltaic systems. Since the voltage level of DC bus and batteries are different, the interface circuit must be able to increase or decrease the voltage level in each power flow direction while limiting the current. In contrast to almost all previous introduced bidirectional converters, the proposed bidirectional converter uses only one auxiliary switch to provide soft switching condition for all semiconductor devices. Low weight, small volume, high efficiency and reduced switching losses are the most important features of the proposed bidirectional converter. The converter operational modes are analyzed and simulation results are given to confirm the theoretical analysis.