本文選題：發(fā)電機定子　切入點：環(huán)氧云母絕緣　出處：《西南交通大學》2017年碩士論文　論文類型：學位論文

【摘要】：發(fā)電機作為電力系統(tǒng)中能源轉(zhuǎn)換的主要電力設(shè)備,其定子絕緣系統(tǒng)是發(fā)電機的關(guān)鍵部分之一,定子絕緣好壞將直接影響發(fā)電機壽命。介電響應(yīng)法近年來運用于絕緣檢測為發(fā)電機絕緣狀態(tài)評估提供了新思路,水分的存在將嚴重影響發(fā)電機定子絕緣檢測結(jié)果,同時水分又是加速發(fā)電機定子絕緣老化的重要因素之一。因此,研究發(fā)電機定子絕緣吸濕特性對發(fā)電機安全運行和定子絕緣狀態(tài)準確診斷具有重要意義。本文從微觀方面闡釋電介質(zhì)理論,通過數(shù)學公式推導出頻域介電譜中介質(zhì)損耗角正切值、復介電常數(shù)實部及虛部的表達式。在弛豫模型上引入單弛豫Debye模型和多弛豫Cole-Cole模型,并建立帶直流電導的多弛豫Cole-Cole模型以對電介質(zhì)頻域介電譜測試結(jié)果進行弛豫過程分析。結(jié)果表明:帶直流電導的多弛豫Cole-Cole模型比單弛豫Debye模型更能符合多體系的復合電介質(zhì)介電弛豫過程。通過搭建發(fā)電機定子線棒老化平臺對發(fā)電機定子線棒進行加速老化,通過濕度箱控制定子線棒試樣所處環(huán)境濕度(M)并搭建頻域介電響應(yīng)(FDS)測試試驗平臺和傳統(tǒng)電阻、電容測試平臺對不同濕度下的定子線棒進行測試。根據(jù)傳統(tǒng)絕緣電阻、電容測試結(jié)果得到傳統(tǒng)時間常數(shù)τ0,并建立帶直流電導的雙弛豫Cole-Cole模型對發(fā)電機定子線棒FDS測試進行擬合分析。結(jié)果表明:通過不同溫度、濕度狀態(tài)測得的τ0得到干燥邊界,利用干燥邊界可判斷定子線棒絕緣是否受潮;雙弛豫Cole-Cole模型對定子線棒FDS測試結(jié)果具有較好的擬合結(jié)果,且隨著M升高,在10-3～103Hz頻率內(nèi),界面極化極化強度△εi逐漸增大,而偶極子轉(zhuǎn)向極化強度△ε2逐漸減小,界面極化占主導作用且其占主導作用的頻寬△f隨M升高逐漸變寬。界面極化弛豫時間常數(shù)τ1與M呈線性指數(shù)關(guān)系,可通過τ1與M的關(guān)系式消除環(huán)境濕度對定子線棒絕緣頻域介電譜的影響。同時,對線棒試樣進行浸水試驗得到不同水分含量的線棒試樣,并進行FDS測試;制作不同厚度的發(fā)電機環(huán)氧云母絕緣材料試樣,并在不同溫度下對環(huán)氧云母絕緣材料試樣進行吸濕試驗。利用Fickian定律對環(huán)氧云母絕緣試樣吸濕過程進行擬合分析,結(jié)果表明:環(huán)氧云母絕緣吸濕過程主要由環(huán)氧樹脂吸濕和復合絕緣材料界面吸濕兩個過程疊加,環(huán)氧云母絕緣初始階段吸濕主要是環(huán)氧樹脂吸濕,界面吸濕飽和率高于環(huán)氧樹脂飽和吸濕率。當環(huán)氧云母材料充分吸濕后,環(huán)氧云母絕緣吸濕后水分主要存在于材料界面處,使得在FDS測試過程中高水分含量的定子線棒絕緣界面極化強度增大,從而在ε"介電譜中將出現(xiàn)局部弛豫峰。在發(fā)電機檢修過程中應(yīng)該定期檢測水冷卻通道的流通性,并定期對繞組表面進行除潮處理,避免水分進入到絕緣內(nèi)部而降低定子繞組絕緣的壽命,為發(fā)電機的維護提供重要的實際參考價值。
[Abstract]:As the main power equipment in power system, generator stator insulation system is one of the key parts of generator. The dielectric response method used in recent years provides a new idea for the evaluation of the insulation state of the generator, and the existence of moisture will seriously affect the test results of the stator insulation of the generator. At the same time, moisture is one of the important factors to accelerate the insulation aging of generator stator. It is important to study the insulation and moisture absorption characteristics of generator stator for the safe operation of generator and accurate diagnosis of stator insulation state. The expressions of tangent value of dielectric loss angle, real part and imaginary part of complex dielectric constant in dielectric spectrum in frequency domain are derived by mathematical formula. The single relaxation Debye model and multiple relaxation Cole-Cole model are introduced into the relaxation model. A multirelaxation Cole-Cole model with DC conductance is established to analyze the relaxation process of dielectric frequency domain measurement results. The results show that the multirelaxation Cole-Cole model with DC conductance is more suitable than the single relaxation Debye model. In the process of dielectric relaxation of composite dielectric, the ageing of generator stator bar is accelerated by setting up a generator stator rod aging platform. The humidity box is used to control the environmental humidity of the stator bar (M) and the frequency domain dielectric response (FDS) test platform and the traditional resistance are built. The capacitance test platform is used to test the stator bar with different humidity. According to the traditional insulation resistance, The conventional time constant 蟿 0 is obtained from the capacitance test results, and a double relaxation Cole-Cole model with DC conductance is established to fit and analyze the FDS test of generator stator bar. The results show that the drying boundary is obtained by using 蟿 0 measured at different temperature and humidity state. The dry boundary can be used to determine whether the stator rod insulation is dampened or not, and the double relaxation Cole-Cole model has a good fitting result for the stator bar FDS test results, and with the increase of M, the polarization intensity 蔚 I of the interfacial polarization increases gradually at the frequency of 10 ~ (-3) ~ 103Hz. However, the polarization intensity 蔚 2 of the dipole turn decreases gradually, and the frequency width f of the interfacial polarization dominates and widens with the increase of M, and the relaxation time constant 蟿 1 of the interfacial polarization shows a linear exponential relationship with M. The relationship between 蟿 1 and M can eliminate the influence of environmental humidity on the dielectric spectrum of stator rod insulation in frequency domain. At the same time, the wire rod sample with different moisture content can be obtained by immersion test and FDS test is carried out. Epoxy mica insulation samples with different thickness were made and moisture absorption tests were carried out at different temperatures. The moisture absorption process of epoxy mica insulation samples was analyzed by Fickian's law. The results show that the moisture absorption process of epoxy mica insulation is mainly superimposed by epoxy resin moisture absorption process and composite insulation material interface moisture absorption process, epoxy mica insulation moisture absorption stage is mainly epoxy resin moisture absorption. When epoxy mica material fully absorbs moisture, the moisture of epoxy mica insulation after moisture absorption mainly exists at the interface of the material. As a result, the polarization intensity of the stator bar insulation interface with high moisture content increases during the FDS test, so that the local relaxation peak will appear in the 蔚 "dielectric spectrum. The flowability of the water-cooled channel should be tested regularly during the maintenance of the generator. In order to avoid moisture entering into the insulation and reduce the life of stator winding insulation, this paper provides an important reference value for generator maintenance.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM31

【參考文獻】

相關(guān)期刊論文 前10條

1 高波;郝長金;尹小兵;王兵;李帥兵;吳廣寧;;溫度對發(fā)電機主絕緣頻域介電響應(yīng)的影響研究[J];中國電機工程學報;2017年03期

2 張征平;尹小兵;涂小濤;郝長金;冉旺;王兵;;水分對大型汽輪發(fā)電機定子線棒主絕緣FDS測試的影響研究[J];絕緣材料;2016年06期

3 王兵;高波;郝長金;尹小兵;陳奎;范建斌;吳廣寧;;溫度和水分對大型發(fā)電機主絕緣FDS特性影響的試驗研究[J];電網(wǎng)技術(shù);2016年02期

4 吳廣寧;鐘鑫;包健康;;溫度對油紙絕緣介電頻譜特性的影響[J];高電壓技術(shù);2015年12期

5 周利軍;李先浪;王東陽;江俊飛;吳廣寧;;不均勻老化油紙絕緣穩(wěn)態(tài)水分分布的頻域介電譜[J];高電壓技術(shù);2015年06期

6 顧國彪;阮琳;劉斐輝;熊斌;;蒸發(fā)冷卻技術(shù)的發(fā)展、應(yīng)用和展望[J];電工技術(shù)學報;2015年11期

7 吳廣寧;段宗超;崔運光;何常新;李先浪;高波;;應(yīng)用極化/去極化電量差模型分析油紙絕緣微水擴散暫態(tài)過程[J];高電壓技術(shù);2015年02期

8 曹雨;吳建東;劉松;王立軍;朱慧盈;尹毅;;單因子老化中定子線棒等溫松弛電流的研究[J];電工技術(shù)學報;2015年01期

9 單葆國;韓新陽;譚顯東;王永培;鄭雅楠;;中國“十三五”及中長期電力需求研究[J];中國電力;2015年01期

10 劉驥;李秀婧;魏新勞;;環(huán)氧-云母復合絕緣固化過程介電響應(yīng)特性[J];電機與控制學報;2014年06期

相關(guān)博士學位論文 前1條

1 周政新;基于智能信息處理的發(fā)電機繞組絕緣故障在線監(jiān)測與診斷技術(shù)研究[D];東華大學;2011年

相關(guān)碩士學位論文 前6條

1 王兵;汽輪發(fā)電機主絕緣多因子老化的介電響應(yīng)特性研究[D];西南交通大學;2016年

2 段宗超;基于頻域介電譜法的變壓器油紙絕緣老化特性研究[D];西南交通大學;2015年

3 李先浪;基于電介質(zhì)響應(yīng)法的油紙絕緣微水擴散特性研究[D];西南交通大學;2014年

4 紀哲強;等溫松弛電流法在發(fā)電機定子線棒檢測中的應(yīng)用[D];上海交通大學;2012年

5 井水益;大電機主絕緣多因子老化試驗系統(tǒng)設(shè)計及定子線棒老化性能研究[D];哈爾濱理工大學;2011年

6 趙慧春;高壓電機定子線棒絕緣結(jié)構(gòu)設(shè)計及其性能研究[D];哈爾濱理工大學;2008年

，

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