Research On Neutral Grounding Mode In 10 KV Distribution Network In Hangzhou District

This Paper combined with the actual situation, through the investigation of hangzhou city 10 kv distribution network characteristics, on the basis of hangzhou urban area of 10 kv distribution network neutral point via arc suppression coil grounding method, this paper mainly based on the characteristics of hangzhou city 10 kv power distribution network, combined with the actual of hangzhou city existing grounding method (neutral through petersen coil grounding mode) to evaluate and optimization, the arc suppression coil capacity, small current alignment pole device, fault line selection and the evaluation of the cost and maintenance, etc, put forward in hangzhou region distribution network optimal design scheme.First, a brief comparison of the distribution network neutral grounding method and its application, and this paper introduces the present situation of distribution network, hangzhou area of hangzhou area small resistance grounding mode transformation feasibility analysis; Second, in hangzhou 10 kv distribution network via arc suppression coil grounding mode operation research, through summarizing found the problem; For the 10 kv via arc suppression coil grounding method, the problems existing in the small resistance grounding system design, given the options of the small resistance grounding mode, and put forward the retrofit scheme of 10 kv distribution network and protection configuration scheme; Finally, the problems of the small resistance grounding mode reform scheme was summarized, and gives concrete solutions.Statistics the existing grounding mode of hangzhou urban area 10 kv distribution network (neutral through petersen coil grounding mode) the existing shortcomings of statistics every 10 kv substation grounding mode of hangzhou city and qualification situation, laying the groundwork for behind the small resistance grounding system design. Analysis of the advantage of neutral point via small resistance grounding mode, neutral point is given by the small resistance grounding mode of the small resistance selection methods, introduction of power distribution network neutral point via small resistance grounding mode of neutral point, puts forward some ideas of the protection of the neutral point via small resistance grounding mode.In this paper, the distribution network neutral point via small resistance grounding method of protection is expounded, and the design in substation of hangzhou city for an example; Qualification of zero sequence current protection for the modification of the small resistance, the zero sequence current protection of the small resistance, as well as the earthing transformer protection are studied; Demonstrates the distribution network neutral point via small resistance grounding method instead of neutral point via arc suppression coil grounding method is feasible, for 10 kv distribution network neutral point via arc suppression coil grounding method is put forward countermeasures to solve the route choice problem, optimization of grid system.