A New Differential Index-Based Fault Detection Scheme for Microgrids

This paper presents a complex differential magnitude angle-based technique for detection of faults in the microgrids (MG). The proposed relaying technique provides an efficient and fast solution for detecting the line faults in the MG. This scheme acquires the current signals of both ends and the voltage signal of one end of the faulted distribution line that are utilized for computation of differential index (DI). The complex plane (CP) constructed from the magnitude and angle of the DI is used to detect the faults in the lines. The proposed protection technique is developed to protect the MG against wide variation of fault scenarios including different types of ground and line faults incepting at different location of the lines. Further, the scheme is tested against some of the most challenging fault cases such as high resistance faults in islanding and grid-connected mode of operation for the MG of different sizes including 9-bus medium voltage MG and IEEE 34 bus distribution system integrated with renewables. Further, the real-time validation of the proposed technique is carried out on real-time digital simulator (RTDS). The results obtained from the extensive test cases in simulation and real-time platforms indicate that the proposed scheme is a potential candidate for fault detection in MG enhancing speed and accuracy.