Fault Models of Inverter-Interfaced Distributed Generators Within a Low-Voltage Microgrid

The traditional overcurrent protection is not suitable for the microgrid. One of themain reasons is that the fault response of the inverterinterfaced distributed generator (IIDG) is very different from that of the rotational generator. This paper develops faultmodels of IIDGs within a low voltage microgrid, including active/reactive power (PQ) controlled IIDGs and voltage controlled IIDGs. Considering that the control strategy of the PQ controlled IIDG varies, this paper introduces adjustable parameters into the model to reflect its fault characteristics as comprehensive as possible. Voltage controlled IIDG is of great significance onmaintaining a stable microgrid. The model of voltage controlled IIDG proposed in this paper keeps its voltage source nature while accomplishing current limiting. The performance of the proposed IIDG fault models has been tested by Matlab simulations. The achievements of this paper are expected to have a positive impact on the development of microgrid fault analysis and protection.