本文選題：換流變壓器　切入點：鐵心飽和不穩(wěn)定性　出處：《沈陽工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著現(xiàn)代電網(wǎng)電壓等級越來越高及超高壓直流輸電技術(shù)應(yīng)用,大型換流變壓器內(nèi)部會出現(xiàn)非常嚴重的直流偏磁現(xiàn)象。這種情況會造成換流變壓器鐵心飽和不穩(wěn)定,引起換流變壓器漏磁場和附加損耗增大,甚至發(fā)生局部溫度過高現(xiàn)象,最后會危害換流變壓器的正常工作運行。換流器的交流側(cè)正序2次諧波分量和直流側(cè)基頻分量通過交直流系統(tǒng)間的相互作用,會引發(fā)換流變壓器中鐵心飽和不穩(wěn)定現(xiàn)象的出現(xiàn)。通過對換流變壓器漏磁場及附加損耗的研究,可以盡最大可能使變壓器運行在正常條件下,從而提高變壓器運行的經(jīng)濟性及安全性。變壓器設(shè)計研發(fā)時,變壓器附加損耗值是一個十分重要的指標,因此,深入研究變壓器鐵心飽和穩(wěn)定性及漏磁場具有重要的工程意義。有限元法需要確定很復(fù)雜的邊界條件,通常計算工作量很大而且計算周期較長,不易實現(xiàn)優(yōu)化設(shè)計;而解析法物理概念分析清楚,方便編寫優(yōu)化程序,同時也在不斷提高精確度,所以,設(shè)計工作人員希望提出一種能夠?qū)⒖焖儆嬎銚Q流變壓器的附加損耗的解析法的公式。換流變壓器發(fā)生直流偏磁時,出現(xiàn)勵磁電流畸變、附加損耗增大等問題。本文首先基于愛潑斯坦方圈對換流變壓器鐵心材料27ZH100電工鋼片的磁特性在不同直流及溫度條件下進行實驗及測量研究,詳細闡述并解釋了BH曲線、BP曲線及磁導(dǎo)率曲線特性,為提高直流偏磁條件換流變壓器漏磁場及油箱損耗仿真準確性提供參考依據(jù)。其次,研究換流變壓器鐵心飽和不穩(wěn)定形成的機理,分析了換流器的交流側(cè)正序2次諧波分量和直流側(cè)基頻分量相互之間作用,建立了換流變壓器鐵心飽和不穩(wěn)定型等值電路。通過傳遞矩陣計算推導(dǎo)出換流變壓器飽和不穩(wěn)定判定因子,提出可以判定鐵心飽和不穩(wěn)定現(xiàn)象的方法。然后在MATLAB建立界面驗證了該方法的正確性。最后,由于變壓器復(fù)雜漏磁場分布,本文通過與理論相結(jié)合分析,在實際計算漏磁場時,通常設(shè)漏磁為理想分布,即變壓器中漏磁力線都與鐵心軸線平行,均作縱向漏磁處理,推導(dǎo)計算出換流變壓器油箱損耗公式。根據(jù)換流變壓器電磁設(shè)計理論,計算換流變壓器漏磁場引起的油箱損耗,得出的解析法計算結(jié)果與有限元仿真結(jié)果基本吻合,驗證了解析法計算方法的可行性。
[Abstract]:With the increasingly high voltage level of modern power network and the application of UHV direct current transmission technology, there will be a very serious DC bias phenomenon in large converter transformers, which will lead to the saturation instability of converter transformer cores. The leakage magnetic field and additional loss of converter transformer are increased, and even the local temperature is too high. Finally, it will harm the normal operation of converter transformer. The interaction between AC side positive sequence second harmonic component and DC side fundamental frequency component of converter through AC / DC system, Through the study of leakage magnetic field and additional loss of converter transformer, the transformer can operate under normal conditions as far as possible. In order to improve the economy and safety of transformer operation, the additional loss value of transformer is a very important index when the transformer is designed and developed. It is very important to study the saturation stability and magnetic flux leakage of transformer core in depth. The finite element method needs to determine very complicated boundary conditions, usually the calculation work is very large and the calculation period is long, so it is difficult to realize optimal design. And the analytical method of physics concept analysis is clear, convenient to write the optimization program, and at the same time is improving the accuracy, so, The design staff hope to put forward an analytical formula that can quickly calculate the additional losses of converter transformers. When DC bias occurs in converter transformers, excitation current distortion occurs. In this paper, based on the Epstein square ring, the magnetic properties of 27ZH100 electrical steel sheet of converter transformer core are studied by experiments and measurements under different DC and temperature conditions. The characteristics of BH curve and permeability curve are described and explained in detail, which provides a reference for improving the simulation accuracy of leakage magnetic field and oil tank loss of converter transformer under DC bias. The mechanism of saturation instability of converter transformer iron core is studied. The interaction between AC side positive sequence second harmonic component and DC side fundamental frequency component of converter is analyzed. The equivalent circuit of saturation instability of converter transformer core is established, and the determination factor of saturation instability of converter transformer is derived by transfer matrix calculation. A method to determine the saturation instability of iron core is proposed, and the correctness of the method is verified at the MATLAB interface. Finally, due to the complex magnetic leakage field distribution of transformer, this paper, by combining with the theory, calculates the leakage magnetic field in practice. The magnetic flux leakage is usually assumed to be an ideal distribution, that is, the leakage force line in the transformer is parallel to the core axis and is treated with longitudinal magnetic leakage. The formula for calculating the oil tank loss of the converter transformer is derived. According to the electromagnetic design theory of the converter transformer, The loss of tank caused by leakage magnetic field of converter transformer is calculated. The calculated results of the analytical method are in good agreement with the results of finite element simulation, and the feasibility of the analytical method is verified.
【學(xué)位授予單位】：沈陽工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM41

【參考文獻】

相關(guān)期刊論文 前10條

1 陳寶亮;李興源;穆子龍;鄧鴻強;應(yīng)大力;;基于特征值方法的高壓直流輸電中諧波不穩(wěn)定分析[J];華東電力;2012年06期

2 曹華貴;;愛潑斯坦方圈測電工鋼片直流偏磁性能方法研究[J];中國制造業(yè)信息化;2009年11期

3 穆子龍;李興源;金小明;郝巍;楊小兵;;云廣特高壓直流送端諧波不穩(wěn)定問題研究[J];電網(wǎng)技術(shù);2008年20期

4 楊小兵;李興源;金小明;郝巍;;云廣特高壓直流輸電系統(tǒng)中換流變壓器鐵心飽和不穩(wěn)定分析[J];電網(wǎng)技術(shù);2008年19期

5 任景;李興源;金小明;吳小辰;;多饋入高壓直流輸電系統(tǒng)中逆變站濾波器投切引起的換相失敗仿真研究[J];電網(wǎng)技術(shù);2008年12期

6 羅隆福;郝強;時建峰;雷圓圓;倪蒙;劉福生;;基于新型換流變壓器的多基頻交直流互聯(lián)系統(tǒng)的諧波特性研究[J];電力科學(xué)與技術(shù)學(xué)報;2008年01期

7 李季;羅隆福;許加柱;李勇;張杰;劉福生;;直流輸電諧波不穩(wěn)定抑制新方法[J];電力自動化設(shè)備;2008年02期

8 曾林鎖;楊松;;直流偏磁對換流變壓器勵磁電流的影響[J];沈陽工業(yè)大學(xué)學(xué)報;2007年05期

9 王莉;;變壓器內(nèi)部漏磁場二維有限元分析[J];中國電力教育;2007年S1期

10 羅隆福;肖華;李勇;俞華;劉福生;;基于新型換流變壓器的12相整流和諧波分析[J];電力系統(tǒng)及其自動化學(xué)報;2006年06期

，

本文編號：1635257