An easy, simple, and flexible control scheme for a three-phase grid-tie inverter system

Abstract

This paper proposed an easy, simple, and flexible control scheme for a three-phase grid-tie inverter system. A half-bridge single-phase grid-tie inverter was designed with a proportional-resonant control, an admittance compensator, and scalar control scheme. This single-phase control method was expanded in a three-phase grid-tie inverter system with duplicating three individual phases with 120° apart. Here are several benefits of the proposed control scheme: (1) it is easy to design by applying single-phase grid-tie inverter control method, (2) it requires less computation burden than that of the conventional three phase control scheme, (3) it provides either a constant power or a constant current to the utility grid with regardless three-phase grid voltage conditions, (4) it provides easily an active and reactive power, (5) it can be designed with a modular manner. A 3-kW power conditioning system has been built and tested in order to verify simulation results and experimental results.