A SOFT SWITCHED CASCADED BOOST CONVERTER FOR PHOTOVOLTAIC APPLICATIONS

Abstract

In this paper, a soft-switched cascaded boost converter connected with a single active switch and simple auxiliary resonant
circuit is adopted for photovoltaic applications with high transformation ratio and low voltage stress across the switch. Switching
losses and electromagnetic interference (EMI) noises are condensed by restricting di/dt of the diode reverse recovery current and
dv/dt of Metal-Oxide semiconductor Field Effect Transistor (MOSFET) drain-source voltage. In this converter an auxiliary
circuit consists of one auxiliary switch, a resonant inductor and a clamp capacitor is operated under zero current transition
technique. The main switch turns-on by means of zero current switching (ZCS) and turns-off by means of zero voltage switching
(ZVS), while the auxiliary switch turns-on and turns-off by means of zero voltage switching (ZVS). This switching configuration
can improve the system efficiency and reduce the switching losses likewise it is very easy to control. The detailed theoretical
analysis and the design equations are described. To verify the performances of the proposed converter, it is demonstrated by
PSIM simulation.