Research and implementation of a single phase stand-alone photovoltaic inverter with parallel topology

A system scheme of the stand-alone photovoltaic inverter based on parallel charge topology for the purpose of improving the energy conversion efficiency and optimizing the battery management was introduced. A novel circuit topology of the DC-AC inverter with the soft switching property using IGBTs and MOSFETs was presented. A modified P&O algorithm for better tracking performance with adaptive step length adjustment was proposed. And a comprehensive strategy for maximum power point tracking (MPPT) with the Constant Voltage Tracking (CVT) algorithm and the modified adaptive Perturbation and Observation (P&O) algorithm was developed. A prototype was implemented to very the feasibility of the proposed scheme.