Low Voltage Ride Through Control for Grid-Connected Inverter Under Balanced and Unbalanced Voltage Drops

In this paper, we present a robust control scheme for grid-connected inverter in order to compensate both positive and negative-sequence reactive power to increase power quality under different voltage drop conditions (Balanced and unbalanced voltage drops). This study is based on a low-voltage ride-through (LVRT) strategy, which is becoming obligatory in low-voltage system due to both security requirement and power-quality consideration. This study is part of project called POWER STATION referenced by 01LY1408C financed by German Federal Ministry of Education and Research. This paper investigated the fault characteristics of a grid under different voltage drop operating conditions. To demonstrate the efficiency of the suggested control, serval simulation tests have been achieved. According to the reached results, good operation of the considered voltage drop control of system has been confirmed.