Implementation of three-phase grid connected inverters with SVPWM-based repetitive control

This paper presents a novel control method for three- phase grid connected inverter with Space Vector PWM. By transforming the three phase time variant system into a two phase time invariant system as known as rotating frame, two separate decoupled control systems can be achieved. Based on conventional PI controller, repetitive control together with grid voltage control is adopted to reduce the harmonics of output current as well as improve dynamic response of the three-phase inverter. Experimental results of a 5kVA prototype can validate the feasibility of the proposed digital control strategy with excellent steady and dynamic performance.