Research On Detection System Of Earth Faults Of An Automatic Resonant Arc Suppression Coil

Neutral ineffectively grounded modes are widely employed in medium and low voltage distribution networks of China. They can contribute to the reliability of power supply, on the other hand the diminished zero sequence currents caused by them make it hard to detect grounded line. It is an important research subject in neutral ineffectively grounded systems that detecting the ground fault accurately. The situation that the neutral resonant grounded systems are mostly employed requires the thoroughly study on the ground fault detection in this mode.The paper makes a deep analysis on neutral resonant grounded mode and educes more characteristic of the zero sequence voltage and zero sequence currents of the transmission lines when the power system has single phase grounded fault. The applicability and advantages and disadvantages of various detection methods are detailed discussed. All this work aim at exploring applicable grounded-line-detection means of the automatic resonant arc suppression coil.In this paper,two ways of detection of grounded line are presented.One is based on zero sequence admittance or susceptance of the transmission line when the fault line is grounded with a lower impedance,the other is based on zero sequence current when the fault line is grounded with a higher impedance.The high impedance is a comprehensive concept which is named when the arc suppression is not start-up but there is true single phase grounded fault.The MATLAB simulation model is created to make a certification to the result of theoretical analysis. The simulation results show that the two criterions are accurate and feasible. Lastly,The integration equipment which has lower investment and higher reliability is designed with function of surveillance and detection.The result of the debugging shows that the device has satisfactory function.