【正文】 and e Iamp。s selfcontradictory in the coexistence of economy and improve the reliability of the power supply network, we must increase the investment cost of the network construction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the poweroff is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic,between the investment and the loss by calculating the investment on power net and the loss brought from poweroff.The revolution of electric power system has brought a new big round construction,which is pushing the greater revolution of electric power technique along with the application of new technique and advanced equipment. Especially, the bination of the information technique and electric power technique, to great ex tent, has improved reliability on electric quality and electric supply. The technical development decreases the cost on electric construction and drives innovation of electric network. On the basis of national and internatio nal advanced electric knowledge, the dissertation introduces the research hotspot for present electric power sy etem as following.Firstly, This dissertation introduces the building condition of distribution automation(DA), and brings forward two typical construction modes on DA construction, integrative mode and fission mode .It emphasize the DA structure under the condition of the fission mode and presents the system configuration, the main station scheme, the feeder scheme, the optimized munication scheme etc., which is for DA research reference.Secondly, as for the (DA) trouble measurement, position, isolation and resume, This dissertation analyzes the changes of pressure and current for line problem, gets math equation by educing phase short circuit and problem position under the condition of singlephase and works out equation and several parameter s Uamp。 指導(dǎo)教師簽字： 指導(dǎo)時(shí)間： 年 月 日（星期 ） 第 次指導(dǎo) 合計(jì) 課時(shí) 指導(dǎo)記錄： 指導(dǎo)教師簽字： 指導(dǎo)時(shí)間： 年 月 日（星期 ） 第 次指導(dǎo) 合計(jì) 課時(shí) 指導(dǎo)記錄： 指導(dǎo)教師簽字： 新疆大學(xué)科學(xué)技術(shù)學(xué)院學(xué)生畢業(yè)論文（設(shè)計(jì)）指導(dǎo)記錄指導(dǎo)教師姓名王海云學(xué)生姓名劉海龍學(xué)生班級(jí)電氣091學(xué)生學(xué)號(hào)20092450037指導(dǎo)時(shí)間： 年 月 日（星期 ） 第 次指導(dǎo) 合計(jì) 課時(shí) 指導(dǎo)記錄： 指導(dǎo)教師簽字： 指導(dǎo)時(shí)間： 年 月 日（星期 ） 第 次指導(dǎo) 合計(jì) 課時(shí) 指導(dǎo)記錄： 指導(dǎo)教師簽字： 指導(dǎo)時(shí)間： 年 月 日（星期 ） 第 次指導(dǎo) 合計(jì) 課時(shí) 指導(dǎo)記錄：