Investigation of Earth Fault Characteristics Under Different Neutral Grounding Methods

Abstract

Medium voltage (MV) distribution systems use different methods for grounding the neutral point. Influences of these grounding methods on the single line to ground (SLG) fault characteristics are discussed in this paper. Jordanian MV network is used as a case study. The network has both underground cables and overhead lines. Simulation models are implemented in both MATLAB®/SIMULINK® and DigSilent/Power Factory®softwares. The models allow detailed investigation of the different fault factors and grounding methods. Results are obtained to evaluate the impact of each grounding method on the SLG fault features. Isolated neutral, solid grounding, resistance grounding and Petersen coil (Arc suppression coil) grounding are compared for different fault locations, fault incidence angles, and fault resistances. Current and voltage waveforms, as well as symmetrical components are used to describe the fault case.