A Two Stage TCDIC with Five-Level Inverter for Stand-Alone and Grid Connected Applications

Abstract

This Paper aimed at developing a standard procedure for the design of large-scale institutional grid-connected solar PV systems using the roofs of buildings and car parks. The standard procedure developed was validated in the design of a grid-connected solar PV system. Grid-connect PV systems with battery back-up (sometimes referred to as uninterrupted power supply or hybrid solar PV systems) are becoming increasingly popular. With solar customers in many states now receiving a low price for electricity sold back to the grid, battery back-up systems can be a viable alternative as they use the electricity stored during the day to run your house at night. They also have the advantage of being able to supply power during power outages.Grid-connected systems do not need batteries which reduces considerably initial capital costs and energy costs. For a comparable load, grid-tied systems use smaller PV arrays than stand-alone systems. In order to address this issue, a two-stage stand-alone scheme consisting of a novel transformer coupled dual-input converter (TCDIC) followed by a five-level inverter is proposed to reduce the harmonic distortion. The proposed TCDIC can realize maximum power point tracking and battery charge control while maintaining the proper voltage level at the load terminal. The simulation results are performed by using Matlab/Simulink software.