Design and development of a non isolated high gain interleaved boost converter for pv interface

Abstract

The energy mix from the non-renewable sources has drooped to a large extent due to many factors resulting in the hunt for power generation from renewable energy sources. Among renewable sources, power generation from photovoltaic (PV) systems has attracted many researchers as sunlight is freely available in abundance with no harmful emissions. However, low voltage output and intermittent nature of PV system are the major issues which need to be addressed. Applications like battery backup systems, electric vehicles, gridconnected systems, power supplies for aircraft, aerospace and medical equipment require a high step-up converter with wider control flexibility including reduced input current ripple and low voltage stress. Many dc-dc converter topologies for PV systems to improve the voltage gain with reduced ripples have been discussed in the previous literature, but most of them are based on isolated topologies. Isolated architecture leads to more losses that reduce the power conversion efficiency and has a complex circuitry. This architecture employs a transformer for attaining high gain. Increasing the number of turns in the transformer improves the voltage gain, but there exists a problem of leakage inductance. The leakage inductance produces substantial voltage spikes which in turn cause large voltage stress across the switches resulting in serious Electromagnetic Interference (EMI) and poor efficiency. A separate circuit to recycle the energy due to leakage reactance has to be added which increases the complexity of the converter. Above all, the saturation effect of transformer results in significant hazards on the top of the failure to work properly. newline