Q and frequency component-based fault and nature detection for hybrid microgrid

Abstract

It is observed that in a hybrid microgrid the current and frequency at a particular node changes as per the number, type of distributed generators (DGs), and grid/islanded connection of microgrid operation. So, the provision of adaptive protection should be the primary concern for updating the relay settings as per the nature of distributed generators, the distance of the fault from the point of common coupling, and the nature of the loads in the microgrid system. The novel contribution of this paper is the implementation of the fuzzy logic-based adaptive protection scheme through analysis of the change in q component and frequency of fault current considering the low X/R ratio of DGs and modes of operation at the instant of series and shunt faults in a hybrid microgrid. In addition, the fault current shared by different DGs is derived for the q component as another contribution. Also, a new relationship between the relay current settings, frequency, and q component of fault current has been identified for the above adaptive relaying. The effectiveness of the proposed adaptive protection scheme for the hybrid microgrid is verified through a simulation case study using Matlab–Simulink software.