本文選題：發(fā)電機(jī) + 環(huán)氧-云母絕緣��； 參考：《西南交通大學(xué)》2017年碩士論文

【摘要】：大型汽輪發(fā)電機(jī)是發(fā)電系統(tǒng)的核心設(shè)備,其主絕緣主要由環(huán)氧云母復(fù)合電介質(zhì)組成,主絕緣的老化狀態(tài)將嚴(yán)重影響發(fā)電機(jī)的使用壽命。本文基于頻域介電譜法(Frequency Domain Spectroscopy,FDS)對(duì)發(fā)電機(jī)主絕緣的老化狀態(tài)評(píng)估展開(kāi)研究,采用理論分析、物理模型構(gòu)建、試驗(yàn)驗(yàn)證的方法,研究了主絕緣的老化特性和介電響應(yīng)特性,對(duì)于利用介電響應(yīng)法實(shí)現(xiàn)發(fā)電機(jī)主絕緣老化狀態(tài)評(píng)估具有重要指導(dǎo)意義。搭建了發(fā)電機(jī)定子主絕緣試樣電—熱—機(jī)械多應(yīng)力聯(lián)合老化試驗(yàn)平臺(tái)和FDS測(cè)試平臺(tái),對(duì)不同老化程度的試樣分別開(kāi)展了 FDS、吸收比、介質(zhì)損耗等測(cè)試,此外通過(guò)試驗(yàn)研究了溫度對(duì)頻域介電譜的影響,運(yùn)用電介質(zhì)極化理論分析了試樣頻域介電譜變化機(jī)理,采用帶直流電導(dǎo)修正的雙弛豫Cole-Cole模型對(duì)FDS測(cè)試值進(jìn)行擬合,研究了老化和溫度對(duì)弛豫模型參數(shù)的影響。試驗(yàn)結(jié)果表明:吸收比和介損的變化規(guī)律反映出線(xiàn)棒絕緣隨加速老化的進(jìn)行而逐漸劣化,驗(yàn)證了老化試驗(yàn)平臺(tái)的有效性;雙弛豫Cole-Cole模型可有效擬合測(cè)試值;隨著老化時(shí)間的增加,試樣的復(fù)介電常數(shù)實(shí)部和虛部均逐漸增大,在較低頻段(10-3～100Hz)增大趨勢(shì)更為明顯,直流電導(dǎo)率和界面極化弛豫強(qiáng)度迅速增大,弛豫時(shí)間呈減小趨勢(shì),分布參數(shù)沒(méi)有明顯的變化規(guī)律,其值分布于0.7～0.9之間;前兩個(gè)周期與后三個(gè)周期的轉(zhuǎn)向極化弛豫的弛豫參數(shù)差異較大,認(rèn)為線(xiàn)棒絕緣老化嚴(yán)重時(shí),絕緣的弛豫機(jī)制發(fā)生改變,產(chǎn)生了一個(gè)新的弛豫過(guò)程;對(duì)不同老化程度的試樣,FDS測(cè)試結(jié)果和弛豫模型參數(shù)具有較高的敏感性并隨老化呈現(xiàn)一定規(guī)律性,因此可將FDS法用于主絕緣的老化評(píng)估。研究了溫度對(duì)主絕緣FDS特性的影響。隨著溫度升高,復(fù)介電常數(shù)實(shí)部和虛部的頻譜曲線(xiàn)向高頻方向移動(dòng);溫度升高加強(qiáng)了界面極化強(qiáng)度和偶極子轉(zhuǎn)向極化強(qiáng)度,在虛部頻譜內(nèi),界面極化弛豫起主導(dǎo)作用的頻率范圍變寬;不同溫度下的界面極化弛豫時(shí)間常數(shù)滿(mǎn)足Arrhenius方程,根據(jù)過(guò)渡態(tài)理論,計(jì)算得到界面極化弛豫對(duì)應(yīng)的活化焓為103.1kJ/mol;活化熵隨溫度升高而增大,表明絕緣體系有序性減小;活化能減小,表明各種極化過(guò)程更易完成,因此可用過(guò)渡態(tài)理論解釋發(fā)電機(jī)主絕緣頻域介電譜的溫度依存性。最后通過(guò)構(gòu)造溫度主曲線(xiàn)不僅能消除溫度對(duì)介電譜的影響,還能拓展測(cè)試頻率范圍。最后對(duì)珠海發(fā)電廠(chǎng)02#機(jī)組開(kāi)展了現(xiàn)場(chǎng)FDS測(cè)試,結(jié)果表明:現(xiàn)場(chǎng)試驗(yàn)測(cè)試結(jié)果與實(shí)驗(yàn)室研究結(jié)論基本一致,可將頻域介電譜法初步推廣應(yīng)用于發(fā)電機(jī)主絕緣老化狀態(tài)的現(xiàn)場(chǎng)評(píng)估。
[Abstract]:Large turbogenerator is the core equipment of power generation system, its main insulation is mainly composed of epoxy mica composite dielectric, the aging state of main insulation will seriously affect the service life of generator. In this paper, based on frequency Domain spectroscopy-FDS in frequency domain, the aging characteristics and dielectric response of main insulation of generator are studied by means of theoretical analysis, physical model construction and experimental verification. It is of great significance to evaluate the aging state of main insulation of generator by using dielectric response method. An electric-thermal-mechanical multi-stress combined aging test platform and a FDS test platform were set up for the main insulation samples of the generator stator. The FDS, absorption ratio and dielectric loss of the samples with different aging degrees were tested, respectively. In addition, the influence of temperature on the dielectric spectrum in frequency domain is studied experimentally. The dielectric spectrum variation mechanism in frequency domain is analyzed by using dielectric polarization theory. The double relaxation Cole-Cole model with modified DC conductance is used to fit the measured values of FDS. The effects of aging and temperature on the parameters of relaxation model were studied. The experimental results show that the variation of absorption ratio and dielectric loss reflects the deterioration of the insulation of the wire rod with the accelerated aging, which verifies the validity of the aging test platform, and the double relaxation Cole-Cole model can fit the measured values effectively. With the increase of aging time, the real and imaginary parts of the complex dielectric constant of the sample increase gradually, and the increasing trend is more obvious in the lower frequency band, the DC conductivity and the interfacial polarization relaxation strength increase rapidly, and the relaxation time decreases. The relaxation parameters of the first two cycles and the last three periods are different greatly. It is considered that the relaxation mechanism of the insulation changes with the aging of the wire rod insulation. There is a new relaxation process which is sensitive to the test results and relaxation model parameters of samples with different aging degrees and has a certain regularity with aging. Therefore FDS method can be used to evaluate the aging of main insulation. The effect of temperature on the characteristics of main insulation FDS is studied. With the increase of temperature, the spectrum curves of real and imaginary parts of complex permittivity move to high frequency, and the interfacial polarization intensity and dipole turning polarization intensity are enhanced with the increase of temperature, which is in the imaginary region spectrum. The frequency range of the interfacial polarization relaxation is widened, and the interfacial polarization relaxation time constant at different temperatures satisfies the Arrhenius equation, according to the transition state theory, The activation enthalpy corresponding to the interfacial polarization relaxation is 103.1 kJ / mol. The activation entropy increases with the increase of temperature, indicating that the order of the insulation system decreases, and the activation energy decreases, indicating that the various polarization processes are easier to complete. Therefore, the transition state theory can be used to explain the temperature dependence of the dielectric spectrum in the frequency domain of the main insulation of the generator. Finally, the influence of temperature on dielectric spectrum can be eliminated and the range of test frequency can be expanded by constructing the main temperature curve. Finally, the field FDS test was carried out for the units of Zhuhai Power Plant 02#. The results show that the field test results are in good agreement with the results of the laboratory study, and the frequency domain dielectric spectrum method can be applied to the field evaluation of the main insulation aging state of the generator.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TM31

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 高凱,談克雄,李福祺,吳成琦;基于神經(jīng)元網(wǎng)絡(luò)的發(fā)電機(jī)定子模型線(xiàn)棒放電模式識(shí)別的研究[J];中國(guó)電機(jī)工程學(xué)報(bào);1999年10期

2 韓紹坤,劉玉蘭,修淑芬;桐馬絕緣在大型發(fā)電機(jī)中的應(yīng)用[J];大電機(jī)技術(shù);1989年04期

3 宋建成,成永紅,高乃奎,謝恒X;基于動(dòng)態(tài)力學(xué)分析的大電機(jī)主絕緣老化診斷[J];中國(guó)電機(jī)工程學(xué)報(bào);2002年05期

4 樂(lè)波,李儉,張曉虹,謝恒X;基于指紋參量的環(huán)氧云母絕緣多因子老化的實(shí)驗(yàn)研究[J];電工電能新技術(shù);2001年02期

5 馬小芹,盧偉勝,樂(lè)波,謝恒X;大型發(fā)電機(jī)主絕緣多因子老化過(guò)程中介損溫譜的研究[J];電工電能新技術(shù);2003年01期

6 宋建成,樂(lè)波,謝恒X;大電機(jī)主絕緣多因子老化試驗(yàn)中試樣線(xiàn)棒端部防暈技術(shù)的研究[J];電工技術(shù)學(xué)報(bào);2000年03期

7 賈志東,高乃奎,樂(lè)波,蔣雄偉,謝恒X;基于動(dòng)態(tài)力學(xué)參數(shù)研究環(huán)氧云母絕緣材料的老化特征[J];電工技術(shù)學(xué)報(bào);2000年04期

8 樂(lè)波,李儉,張亮,謝恒X,宋建成;環(huán)氧云母絕緣定子線(xiàn)棒多因子老化過(guò)程中交流參量變化規(guī)律的研究[J];電網(wǎng)技術(shù);2001年03期

9 郝艷捧,王國(guó)利,閆波,蔣雄偉,賈志東,謝恒X;大電機(jī)定子線(xiàn)棒絕緣狀態(tài)診斷的研究進(jìn)展[J];高電壓技術(shù);2001年01期

10 樂(lè)波,謝恒X;基于模糊輸出BP神經(jīng)網(wǎng)絡(luò)的電機(jī)主絕緣老化狀態(tài)評(píng)估方法[J];中國(guó)電機(jī)工程學(xué)報(bào);2005年02期

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