| Worldwide,the studies of intelligent distribution network technology are behind the main power system.The research of domestic distribution automation technology also started late,until 2010,most of the urban distribution networks are composed of traditional lines without intelligent transformation.Once a failure occurred on the line,it would mostly lead to a full line trip with a large number of power outage users and a long blackout time,the reliability of the distribution network is relatively low.With the development of society,the demand for continuous electric power supply and higher power quality is becoming urgent and harsh.Therefore,it is essential to improve the reliability of distribution network by the implementation of intelligent transformation.Currently,when dealing with distribution network failure,the centralized type,voltage type,and demarcation type intelligent terminals are used to realize the remote measuring,remote controlling,remote communicating and fault recovery.But China started relatively late in the intelligent distribution network construction,and the level of development varies from region to region.Thus,the incomplete working principle would lead to the imparity,mis-operation and refusing action,self-healing failure occurs frequently,thus,it is in urgent need to improve the distribution network.Relying on the distribution automation project and the distribution automation system put into operation in October 10,2011 by Jinan power supply company,how to perfect an intelligent self-healing technology to handle various kinds of distribution network fault flexibly and correctly is researched and discussed in this paper based on the segmented main line model and the radiation line model.Based on the segmented main line model,the working principle and related cases that different kinds of distribution automation dealing with instantaneous single-phase grounding,permanent single-phase grounding,instantaneous muti-phase fault(including interphase short circuit),and permanent muti-phase fault.The technical defects were analyzed and improved.For the communication interrupt frequently occurred in the terminal equipment,the action strategy and impact of different kinds of distribution automation are studied.In this paper,the technical difficulties and corresponding solutions of the distribution automation of complex connection mode(radiation lines),comparing with that of segmented main lines are studied from the shallower to the deeper,and the action procedure of faults occurred in different sections is analyzed comprehensively combined with cases.It is verified that the proposed distribution automatic fault self-healing technology could improve the intelligent control level and the power quality of distribution network through comparing and analyzing the relevant indicator data of power supply reliability before and after the distribution automation reform of Jinan power supply company. |
