The Open Electrical & Electronic Engineering Journal

2015, 9 : 253-262
Published online 2015 July 31. DOI: 10.2174/1874129001509010253
Publisher ID: TOEEJ-9-253

Study on Selective Leakage Protection System of Mine High Voltage Grid Based on Harmonic Phase Comparison

Liu Zhongfu , Zhang Junxing , Shi Lixin and Yang Yaning
College of Information & Communication Engineering, Dalian Nationalities University, Liaoning, Dalian, China.

ABSTRACT

As for the wide application of arc suppression coil to the grounding in neutral point of mine high voltage grid, grid leakage fault rules and harmonic characteristics of the neutral point grounding system through arc suppression coil are analyzed, the selective leakage protection program “zero-sequence voltage starts, fifth harmonics of grid zero-sequence voltage and zero-sequence current are extracted for phase comparison” is proposed, and corresponding fifth harmonic extraction circuit and power direction discrimination circuit are designed. The experimental results show that the protective principle applies not only to the neutral point insulated power supply system, but also to the power supply system in which neutral point passes arc suppression coil, which can solve selective leakage protection problems under different neutral grounding ways, improving the reliability of selective leakage and guaranteeing the stability of the action value.

Keywords:

High-voltage grid, Selective leakage protection, The fifth harmonic phase comparison, Zero-sequence voltage.