Neutral Grounding Of Urban Cable Network And Its Protection Configuration For Distributed Generation

With the rapid development of economy,the reliable supply of electrical energy plays an irreplaceable role in normal production and life.Distribution network of high reliability and transmission of high capacity is the key to ensure the steady and reliable power supply.At present,there are some shortcomings in our cities' 10 kV power distribution system,like cable-dominated,low accuracy rate of line selection device for low current,capacity of initial designed arc suppression coil cannot meet the need of power network and so on.Meanwhile,as more and more photovoltaic power station put into the city grid,distributed PV capacity increased,and the directed access way of photovoltaic power supply to distribution networks has brought new challenges to the stability and security of the grid.Therefore,improving the reliability of power supply is the problem should be solved quickly in the development of distribution system in our country.This article stars from the problem that the urban distribution network grounding protection which is related to cable-dominated and DG access and launches an in-depth study.At the same time,the article proposes a proposal that changed the original neutral point by the arc suppression coil grounding way to neutral point by a small resistance grounding,combining with reality of Bayan Nur Power Grid,and analyzed the urban 10 kV distribution network neutral point grounding way and retrofit.In addition to,the article had do analysis to the influences to network protection of distributed PV to access distribution networks.And suggested an improved method based on the adaptive protection of capacity density in distributed power generation area.