A novel modelling and control strategy for a full-wave ZCS quasi-resonant boost converter for a PV-based battery charging system

In this paper, a novel modelling and control strategy is proposed for a DC-DC quasi-resonant boost converter utilised in a photovoltaic-based (PV-based) battery charging system. The MOSFET switch of the boost converter is operated at zero current using a resonant tank, providing soft-switching functionality, to reduce the switching losses experienced by conventional boost converters. The principles of operation of the utilised converter are analysed in detail and a characteristic function representing the model of quasi-resonant converter circuit is derived. This model is then used to design and implement a frequency control technique, which will maintain a constant DC voltage at the output stage of the converter to charge the battery. Simulation studies are conducted using MATLAB Simscape toolbox to evaluate the performance of the proposed controller. Simulation results validate the soft-switching functionality of the converter and its ability to reach and maintain the desired output voltage for charging a battery load in the presence of varying input voltage generated by a PV system with intermittent nature.