Fast Earth-Fault and Feeder Detection in Medium-Voltage Distribution Power Grids

Abstract

Safety and reliability of medium-voltage distribution power grids depend on the rapid detection and elimination of faults. The most common faults in MV power grids are single-phase earth faults. Traditional methods for faulty feeder detection are not fully reliable and their sensitivity must be increased by connecting of an auxiliary resistor, which cancels the compensation of the fault current. Simple, fast, and reliable algorithms for both, earth fault and faulty feeder detection in MV distribution power grids are proposed in this paper. The methods are based on computation of angle between feeder currents using a dot product, they are computationally efficient and eligible for real-time environment. Their performance is verified on the set of 154 earth fault records, measured in a MV distribution power grid of 22 kV.