Semi Active Rectifier for High Output Voltage Applications in Boost Mode

A method for developing isolated buck boost converter in boost mode is projected in this paper. This method is more efficient because of soft switching operation, low voltage stress on active switches and also a single stage power conversion. Low voltage stress on the components is accomplished. From this efficiency of the converter also improves. On the basis of two switch non isolated buck boost converter, isolated buck boost converter in boost mode is proposed. Semi active rectifier (SAR) is also proposed in this paper. It acts as a secondary rectification circuit for isolated buck boost converter. It improves the converter voltage gain and reduces the voltage stress on the devices in the rectification circuit. By choosing a transformer with a smaller turn’s ratio and reduced parasitic parameters, efficiency can be improved. Primary side of transformer is taken as full bridge isolated buck boost converter. To obtain isolated buck boost conversion, phase shift control strategy is applied to the full bridge. Over a wide load and voltage range, soft-switching performance of all active switches and diode can be achieved.