Discussion on Neutral Grounding Mode for Medium Voltage System

The paper analyzed the modes of neutral effective grounding and neutral non-effective grounding, and compared two modes of small resistance grounding and arc suppression coil grounding. The conclusion is that small resistance grounding system is helpful for restricting over-voltage under fault condition, easy to detect fault location, greater disturbance for communication etc.; arc suppression coil grounding system has smaller grounding current, slow down the recovery speed of voltage, good electromagnetism compatibility, disadvantage in seeking fault line. It is pointed out that to select suitable grounding mode will be helpful for safe operation of power network.