Analysis of voltage variation and unbalance of 10kV line break in a power distribution network

Distribution network’s line break is a typical fault type of distribution network. Generally speaking, line breakage faults can occur at any position of the line, which can be roughly divided into power supply side, middle section, and load side. Generally speaking, after a single-phase line break occurs, the relative ground voltage of the line break phase increases, while the two-phase voltage of the phase without line break decreases. However, the location of the line break point is closer to the power side or the load side, and the voltage changes between the fault phase and the non fault phase are not exactly the same. This paper analyzes the principle of neutral point voltage displacement and voltage asymmetry caused by single-phase line break in power distribution system with neutral non-effectively grounded through formula derivation. Finally, a typical case is analyzed to investigate the voltage offset caused by single-phase line break.