Schematic design and application study on low resistance grounding system

With the widely use of power cable in distribution networks,the grounding system via arc suppression coil has exposed some limitation.According to the current operation state of Changsha distribution network,the advantages and disadvantages of the low resistance grounding system and arc suppression coil grounding system were analyzed in the paper.The novel schematic design was researched by using 10 kV Luojiazui power station model,which was adopted the low resistance grounding system to substitute the arc suppression coil grounding system.The selection of low resistance quantity and the earthing transformer's capacity was presented.The fault point step voltage on the condition of single phase fault was also calculated and analyzed.The new grounding system was realized and normal operation.Therefore,the research has important theoretical and project practical values to the low resistance grounding system popularization application in the Changsha city distribution power networks.