RESEARCH ON ADAPTIVE TRIPPING FOR SINGLE PHASE EARTH FAULT IN NEUTRAL POINT NON-EFFECTIVELY GROUNDED SYSTEM

摘要

Running with single-phase earth fault improves reliability of power supply in neutral point non-effectively grounded system,but arc-grounding and intermittent fault caused over-voltage is most likely to damage insulating security.In view of developing line-selection techniques,the increasingly success ratio of that has met the requirement on site,a new method is proposed for adaptive earth fault protection in neutral non-effectively grounded system,to be specific,the reliability of online monitoring fault line selection,the condition of over-voltage and insulation of line,severity of fault,line types and power supply reliability demand to the loads,adaptive fault line-selecting whether or when to trip,all above factors are taken comprehensively into consideration.The adaptive protection technology has been applied with well effect in enterprise grid of Shandong province of China.