Fault current contribution of Renewable Distributed Generation: An overview and key issues

Fault current contribution of Renewable Distributed Generation (DG) has become a major concern in present power industries. Installation of DG not only alters the load flow in the distribution network but can also affect the fault current during a grid disturbance. The effect of DG integration on a system can be investigated for two different types of DG: Inverter based DG (IBDGs), and Non-Inverter based DG. IBDGs have the lowest contribution to faults due to its overload handling characteristic. On the other hand, Non-Inverter based DG, generally synchronous and induction machines based DG, have higher contribution to fault currents. The contribution of inverter based and non-inverter based DGs to the fault currents depends on multiple aspects such as, control methods implemented under fault condition, penetration factor, fault location and system impedance. This paper presents a comprehensive overview of the fault contribution of renewable distributed generation.