Single-Phase Short Circuit Determining Algorithm at Hydroelectric Power Plant Auxiliaries Network

The first part of the paper is devoted to the description of the hydroelectric power plants auxiliaries network features. The factors influencing the emergency modes course are considered. The analysis of the existing neutral grounding modes is performed. After that, the analysis of existing methods of fault location in medium-voltage networks is carried out. Algorithms based on various physical principles and using both one-sided and two-sided measurements of the regime parameters are considered. The mathematical model of signal processing in Matlab Simulink is shown as an example. The principle of operation of each presented algorithm is briefly described and their application for the station auxiliaries network is analyzed. After that, an algorithm for the operation of earth fault protection at the hydroelectric power plants auxiliaries network is proposed. High-frequency rejection is applied to increase the accuracy of the protection while the distance to the damage site searching. This approach allows reducing the time for damaged feeder and site determination.