A novel single-stage power conversion system based on T-inverter for photovoltaic system connected to single phase AC grid

摘要

A novel photovoltaic system based on T-inverter connected to a single-phase grid is proposed in this paper to reduce the number of semiconductor device, size and total cost of the system. T-inverter is a DC/AC converter composed of an H-bridge cell, a capacitor and a pulse transformer capable of controlling the output ac voltage and input dc voltage at any moment. T-inverter is proposed in this paper as an alternative for common two-stage intermediary power conversion (DC/DC and DC/AC) in photovoltaic system. The appropriate control structure such as modified incremental conductance method for tracking the maximum power point and the double-loop control for regulating the power injection to the grid and stabilizing Tinverter capacitor voltage is presented and is discussed in detail. The validity of operation of the proposed system is verified through simulation.