Analysis of islanding detection methods for grid-connected distributed generation in provincial electricity authority distribution systems

This paper presents a comparison study of two major distributed generation islanding detection methods including rate of change of frequency (ROCOF) and over/under frequency (OUF) techniques which could be used for Provincial Electricity Authority (PEA) distribution systems. The analysis is based on the detection time in different scenarios and false operations. Two practical distribution systems including 133-bus and 54-bus systems from PEA are used as case studies and DIgSILENT PowerFactory software is used as simulation tool. Simulation and test results show that ROCOF technique can detect islanding phenomena faster than OUF technique when the system has only one distributed generation. However, ROCOF technique is more sensitive to false operation than OUF technique.