Single-Phase Single-Stage Grid-Tied Solar Inverter

Abstract

The electrical energy generation with renewable energy sources is increasing significantly. By integrating renewable sources with utility grid, the power is injected into the grid. This paper presents the design and simulation of a single-phase grid-tied solar inverter. The topology here used for grid tie is of single power stage. A control strategy in synchronous dq frame is developed for single-phase single-stage grid-connected photovoltaic (PV) inverter. This control scheme together with MPPT algorithm is proposed to obtain maximum power point operation and to control the active power flow between panel and grid. The control scheme forces the d-axis current to track the reference current obtained from MPPT to ensure that the maximum power is drawn by the grid from the panel. The phase synchronization is obtained by using PLL. A hardware implementation of single-phase PWM inverter is also employed.

Keywords: dq control, MPPT, PLL, photovoltaic systems, single-phase grid-tied inverter