Design and implementation of a PV DC/DC converter with high efficiency at low output power

This paper presents a PV DC/DC converter which has high efficiency at low output power. The factors that influence the efficiency are analyzed firstly. On the basis of the analysis, a converter base on interleaved multiple-phase buck converter is proposed. By controlling the number of the phases that is active and the angle shift of the PWM carrier between the active phases, the converter can operates near the point with highest efficiency regardless the variation of output power. High efficiency can be obtained at both full output and low output power, which may increase the energy capture from the PV cell. Analysis, design and implementation of the converter are presented in detail. Tested results show an obvious improvement of the efficiency at low output power, which ratifies the validity of proposed topology and control strategy in PV DC/DC converter application.