本文選題：特高壓變壓器 + 直流偏磁��； 參考：《華北電力大學(北京)》2017年博士論文

【摘要】：高壓直流輸電和磁暴現(xiàn)象引起的變壓器直流偏磁效應嚴重影響變壓器的安全運行。特高壓電網(wǎng)采用八分裂導線,電阻小,更易遭受直流擾動的侵害。特高壓變壓器作為特高壓電網(wǎng)的關鍵設備,其運行的可靠性與安全性直接關乎整個電網(wǎng)的正常運行。為此,本文針對特高壓變壓器的直流偏磁問題進行了計算與分析。主要研究內(nèi)容和取得的成果如下:基于特高壓變壓器鐵心材料的高導磁性和強非線性特性,提出了基于空載簡化電路模型下的分段解析法,進行直流偏磁條件下計算結(jié)果準確性問題的研究與分析。繼而以解析解的計算結(jié)果為基準,對比分析四階龍格庫塔法的數(shù)值計算結(jié)果。結(jié)果表明,在特高壓變壓器的直流偏磁數(shù)值計算中,可通過人為增大串聯(lián)電阻和適當減小計算時間步長來獲得較為準確的直流偏磁特性。該研究結(jié)果為實際特高壓變壓器進行基于場路耦合法的直流偏磁計算提供了一種有效解決方法。根據(jù)特高壓變壓器實際的結(jié)構(gòu)參數(shù)和電氣連接方式,建立變壓器的場路耦合模型,分析串聯(lián)電阻值和時間步長對直流偏磁計算結(jié)果的影響。人為增加一個串聯(lián)電阻,改變了變壓器本身的電路結(jié)構(gòu),導致串聯(lián)電阻后側(cè)的電壓偏離所施加的額定交流電壓。因此,提出電壓補償原理,進行電壓補償?shù)牡嬎�。計算結(jié)果表明,電壓補償可有效消除串聯(lián)電阻值導致的電流計算偏差。在此基礎上,進行特高壓變壓器不同直流偏磁電流下的空載直流偏磁仿真計算,獲得勵磁電流和磁場特性。為提高特高壓變壓器空載直流偏磁計算效率,提出了一種基于動態(tài)電感-勵磁電流曲線的空載直流偏磁快速計算方法,該方法避免了不同直流偏磁電流情況下重復進行磁場模型的動態(tài)電感的求解。通過與場路耦合算法計算結(jié)果的對比,驗證了該方法的正確性和有效性。同時,該方法大大節(jié)省了計算時間,提高了計算效率,為變壓器的直流偏磁計算提供了一種快速簡便的計算方法。針對特高壓變壓器負載運行方式下的直流偏磁問題進行研究與分析。增大原邊串聯(lián)電阻,可使原邊電流中直流分量的計算結(jié)果接近于直流偏磁電流理論值,提高計算結(jié)果的準確性。分析直流偏磁情況下不同負載電阻對特高壓變壓器高、中壓繞組電流的影響,獲得了負載由過載到額定,再到輕載直至空載運行狀態(tài)下高、中壓繞組中電流的變化規(guī)律。進行不同直流偏磁電流時負載運行方式下的直流偏磁計算和電流特性分析。基于不同直流偏磁電流下計算得到的空載與負載電流,進行無功功率和渦流損耗計算及其特性分析,為特高壓變壓器耐受直流偏磁能力的評估提供參考。本文所開展的研究工作為進行特高壓變壓器直流偏磁條件下的溫升計算奠定了計算基礎。
[Abstract]:The DC bias of transformers caused by HVDC transmission and magnetic storm seriously affects the safe operation of transformers. UHV power grid adopts eight-split conductors with low resistance and is more vulnerable to DC disturbance. As the key equipment of UHV power network, UHV transformer's reliability and safety are directly related to the normal operation of the whole power network. In this paper, the DC bias of UHV transformer is calculated and analyzed. The main research contents and achievements are as follows: based on the high conductance magnetic and nonlinear characteristics of UHV transformer core material, a piecewise analytical method based on no-load simplified circuit model is proposed. The accuracy of calculation results under DC bias is studied and analyzed. Then the numerical results of the fourth order Runge-Kutta method are compared and analyzed on the basis of the analytical solution. The results show that in the numerical calculation of DC bias of UHV transformers, the more accurate DC bias characteristics can be obtained by artificially increasing the series resistance and appropriately reducing the calculation time step. The results provide an effective solution for DC bias calculation of UHV transformers based on field-circuit coupling method. According to the actual structure parameters and electrical connection mode of UHV transformer, the field circuit coupling model of transformer is established, and the influence of series resistance and time step on the calculation result of DC bias magnetic field is analyzed. Artificially adding a series resistor changes the circuit structure of the transformer itself and causes the voltage at the rear side of the series resistance to deviate from the rated AC voltage applied. Therefore, the principle of voltage compensation is put forward, and the iterative calculation of voltage compensation is carried out. The calculation results show that voltage compensation can effectively eliminate the current calculation deviation caused by series resistance. On this basis, the simulation calculation of no-load DC bias magnetic field of UHV transformer under different DC bias current is carried out, and the excitation current and magnetic field characteristics are obtained. In order to improve the efficiency of no-load DC bias calculation of UHV transformer, a fast calculation method of no-load DC bias based on dynamic inductor-excitation current curve is proposed. This method avoids repeated calculation of the dynamic inductance of the magnetic field model under different DC bias current. The correctness and validity of the method are verified by comparing with the results of the field circuit coupling algorithm. At the same time, this method greatly saves calculation time and improves calculation efficiency. It provides a fast and simple calculation method for DC bias calculation of transformer. The DC bias of UHV transformer under load operation mode is studied and analyzed. The calculation results of DC component in the primary edge current can be close to the theoretical value of DC bias current and the accuracy of the calculation result can be improved by increasing the primary edge series resistance. This paper analyzes the influence of different load resistance on the current of UHV transformer under the condition of DC bias magnetic field, and obtains the variation rule of the load from overload to rating, from light load to high running state of no-load, and middle voltage winding. The calculation of DC bias and the analysis of current characteristics under different load operation modes are carried out. Based on the calculation of no-load and load current under different DC bias magnetoelectric current, the reactive power and eddy current loss are calculated and their characteristics are analyzed, which provides a reference for the evaluation of DC bias resistance of UHV transformer. The research work in this paper lays a foundation for the calculation of temperature rise of UHV transformer under DC bias.
【學位授予單位】：華北電力大學(北京)
【學位級別】：博士
【學位授予年份】：2017
【分類號】：TM411.3

【參考文獻】

相關期刊論文 前10條

1 李鵬;李金忠;崔博源;董勤曉;時衛(wèi)東;趙志剛;;特高壓交流輸變電裝備最新技術發(fā)展[J];高電壓技術;2016年04期

2 林湘寧;楊國穩(wěn);翁漢t ;潘美;謝志成;鄭濤;;直流偏磁下變壓器無功消耗增多對系統(tǒng)電壓的影響分析[J];高電壓技術;2016年01期

3 劉連光;王開讓;郭世曉;鄭寬;魏凱;劉春明;王澤忠;董博;;雙電壓等級電網(wǎng)GIC的相互作用特征[J];中國科學:技術科學;2015年12期

4 劉連光;秦曉培;葛小寧;;基于U-I曲線的單相自耦變GIC無功損耗算法[J];電力自動化設備;2015年12期

5 韓豐;宋福龍;羅金山;路暢;;“十三五”輸電網(wǎng)發(fā)展重點研究[J];中國電力;2015年01期

6 官瀾;李光范;李博;趙志剛;李金忠;張書琦;;我國特高壓電力變壓器研制技術及發(fā)展[J];變壓器;2014年08期

7 劉振亞;;中國特高壓交流輸電技術創(chuàng)新[J];電網(wǎng)技術;2013年03期

8 劉渝根;冷迪;田資;成文杰;;基于ANSYS Maxwell的750kV自耦變壓器直流偏磁仿真[J];高電壓技術;2013年01期

9 潘超;王澤忠;楊敬t@;劉連光;;變壓器直流偏磁瞬態(tài)場路耦合計算的穩(wěn)定性分析[J];電工技術學報;2012年12期

10 王澤忠;潘超;周盛;劉連光;;基于棱邊有限元的變壓器場路耦合瞬態(tài)模型[J];電工技術學報;2012年09期

相關博士學位論文 前2條

1 張冰;大型電力變壓器的GIC影響效應研究[D];華北電力大學（北京）;2010年

2 姚纓英;大型電力變壓器直流偏磁現(xiàn)象的研究[D];沈陽工業(yè)大學;2000年

相關碩士學位論文 前5條

1 趙峰;特高壓變壓器的主絕緣設計研究[D];華北電力大學;2013年

2 張婕;特高壓變壓器涌流識別及直流偏磁對其影響研究[D];華北電力大學;2012年

3 肖華;特高壓直流輸電引起的變壓器直流偏磁問題的研究[D];西南交通大學;2010年

4 宋帆;特高壓GIS設備的渦流及其相關問題的研究[D];沈陽工業(yè)大學;2009年

5 王洪亮;高壓直流輸電單極大地回線方式運行時接地極電流的研究[D];西南交通大學;2007年

，

本文編號：1799655