The impact of synchronous distributed generation on voltage dip and overcurrent protection coordination

This paper investigates the impact of synchronous distributed generation (DG) in MV network on coordination between overcurrent protection in MV feeder and voltage dip sensed by customer at LV side. DG is expected to support keeping the remaining voltage of a feeder high during voltage dip. DG location affects the level of support that DG can provide. Depending on the location, DG can either increase or decrease short circuit current. Both increasing and decreasing the short circuit current needs readjustment of overcurrent protection, either to ensure the coordination with downstream overcurrent protection, or to maximize DG support during the dip. A voltage dip immunity of a sensitive equipment (SE), which is shown in a voltage-time characteristic, is used to investigate the behaviour equipment during the dip