Abstract. Voltage sags caused due to unknown faults at the grid are the key power quality issues faced by industrial consumers. These sags often cause disruption in manufacturing processes and result in substantial economic losses. In order to deal with such problems a voltage sag compensator VSC consist of a voltage source inverter coupled through a series transformer with grid line is often installed since it is among the cheapest solutions against the sags to save the critical loads from damaging. However, a problem of inrush transient current occurs as the series transformer gets energized to compensate for the load voltage. This not only affects the critical loads but also triggers the circuit breakers installed to avoid overcurrent of the compensator. This paper proposes a series of voltage sag compensator based on a current-controlled voltage source inverter CRVSI with the reduced magnitude of transformer inrush current. The proposed VSC is based on a current control technique applied in a stationary frame of reference for the desired operation.
