Analysis and Application of the Neutral Voltage in Resonant Grounding Grid

摘要

There are often some problems during operation of the resonant grounding grid, such as tracking failure, excessive tuning, and oversize residual current caused by compensation not matching grounding fault. A new idea is proposed to solve the problems about using of the neutral voltage detection, analysis and calculation. Firstly, neutral voltage characteristics are analyzed. Secondly, neutral voltage is applied to the calculation of tracking sensitivity, and the problems of tracking failure and excessive tuning are effectively solved. Thirdly, change of operation mode and grid disturbance are distinguished by using characteristics of neutral voltage variation. Lastly, the formulas of neutral voltage ranges are derived, which can distinguish high-resistance grounding fault from low-resistance grounding fault and achieve a smart compensation. This solves the problem of excessive residual current. Simulations verified the above conclusions and the results are satisfied.