Stand‐alone multiple input photovoltaic inverter for maximum power extraction and voltage regulation under mismatched atmospheric conditions

In this study, a single-phase multi-input photovoltaic (PV) inverter has been proposed for simultaneously achieving maximum power extraction and load voltage regulation under various operating scenarios involving weather intermittency and dynamic loading. This is achieved by maintaining the PV modules in series for similar atmospheric conditions and by allowing isolated operation of individual modules during mismatched atmospheric conditions among different modules. The weather-dependent operation of the modules allows efficient extraction of maximum power from all the modules by avoiding the modules to operate at the least maximum power point (MPP) among them, which has been a limitation of classical techniques aiming at MPP with multiple modules. A comprehensive analysis of the proposed inverter topology and its associated synchronous reference frame-based control scheme has been carried out by considering a wide range of operating scenarios in terms of (i) maintaining the operation closer to MPP under varying irradiance levels and temperature; (ii) regulated output voltage for load variation. The appropriateness of the scheme has been compared with the existing state-of-the-art topologies. In addition to the MATLAB simulation, validation has been carried out on a 300 W laboratory prototype.