A novel, high efficiency, high gain, front end DC-DC converter for low input voltage solar photovoltaic applications

Several solar PV systems require a high gain front end dc-dc converter. Conventional dc-dc converters can offer limited gain and their efficiency drops as the gain requirement increases. This paper proposes a high gain, high efficiency dc-dc converter suitable for low voltage PV fed applications. The underlying concept of the converter is based on energy storage in an intermediate capacitor by a coupled inductor. In the proposed converter, a clamp circuit is used to recycle the energy stored in the leakage inductance (of the coupled inductor) to increase the efficiency. This facilitates realization of high voltage gain without extreme duty cycle. Presence of a clamp circuit reduces voltage stresses in the main switch, which leads to the use of low voltage switch having a low “on-state” resistance (R_DS(ON)). Also, diode reverse recovery problem is eliminated, which reduces the losses across the diode and improves the efficiency. The operational principle of the converter is discussed in detail and all the relevant analysis is included.