Study of adaptive fault current algorithm for microgrid dominated by inverter based distributed generators

The fault characteristic of inverter interfaced DG is very different from that of synchronous rotating generators. Traditional protection methods based on large fault current are no longer applicable to inverter-only supplied microgrid. This paper analyzes the fault behaviour of inverter based microgrid, and proposes an adaptive fault current protection algorithm for this type of microgrid. According to the fault characteristic of inverter interfaced DG, it uses fault component current which only presents in fault condition. The result is simulated and proved by DigSilent.