Islanded distributed generation system with feedforward PR-EFLL control for AC-electric vehicle charger

摘要

This study deals with the islanded distributed generation system (IDGS), which is used to feed different types of loads such as AC-EVs (electric vehicles) and non-linear home load. The IDGS consists of solar photovoltaic (PV) array with a storage battery. In IDGS feeding, the EVs and non-linear load, the currents contain high harmonics. Due to which, the generation of sinusoidal voltage with good quality at common coupling point (CCP) is very challenging. Therefore, a feedforward proportional resonant (PR) controller is proposed with enhanced frequency locked loop (EFLL) control algorithm to eliminate the CCP voltage harmonics and provides the high tracking capability of AC voltage as compared to the conventional proportional integral (PI) control. As a result, the voltage source converter control generates the balanced and sinusoidal CCP voltages even at unbalanced load condition. The proposed EFLL-based control algorithm is capable to reject the DC-offset component from the load current. Moreover, the DC-link voltage regulation and peak power extraction of solar-PV array are achieved through bidirectional DC-DC converter control. This BDC control is used to balance the active power flow in the islanded system. The effectiveness of the proposed IDGS is validated, through simulation as well as experimental steady-state and dynamic test results.