Analysis of Neutral Point Voltage Characteristics in Small Resistance Grounded System with Single-Phase Line Break Faults in Distribution Network

In recent years, line break faults in distribution networks have become increasingly common. This paper focuses on small resistance grounded systems, analyzing the characteristics of neutral point voltage shifts under different conditions of fallen conductors following a line break. The study considers various fault factors, including fault location, grounding resistance, and load impedance, and investigates three scenarios: line break without grounding, line break with grounding on the power supply side, and line break with grounding on the load side. The research finds that in all three cases, the amplitude of the neutral point voltage is primarily influenced by the grounding resistance-the larger the grounding resistance, the greater the amplitude of the neutral point voltage. Finally, a model of a small resistance grounded system with a single-phase line break fault was built using MATLAB/Simulink simulation software, which confirmed the accuracy of the analyzed results.