This paper proposes a fault ride-through (FRT) operation for a single-phase grid-tied inverter with a minimized inductor in order to reduce the inverter output current overshoot. The inverter output current overshoot becomes very high at a grid voltage drop and recovery, when a low-inductance interconnected inductor is used. Hence, a grid-voltage fault stops the operation of the grid-tied inverter due to overcurrent protection. This paper proposes a high-speed freewheel mode during the voltage sag in order to reduce the inductor current overshoot. Moreover, the inductance of the interconnected inductor is designed by considering the grid voltage recovery operation of the inverter with the high-speed freewheel mode. Consequently, by using the proposed method, the grid-tied inverter continues to operate without interruption during the grid voltage fault. With the proposed method, the maximum inductor current overshoot during the voltage sag is reduced from 755% to 141%, compared with the conventional FRT operation.
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