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

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 T-inverter capacitor voltage is presented and is discussed in detail. The validity of operation of the proposed system is verified through simulation.