本文選題：對(duì)稱分量法 + 輸電線路解耦�。� 參考：《廣西大學(xué)》2017年碩士論文

【摘要】：電力系統(tǒng)在運(yùn)行過(guò)程中,會(huì)發(fā)生各種不同類型的故障,而電力系統(tǒng)故障的分析計(jì)算對(duì)于電力系統(tǒng)的規(guī)劃設(shè)計(jì)、事故分析以及電力系統(tǒng)的整定運(yùn)行都有著十分重要的指導(dǎo)作用,所以人們對(duì)電力系統(tǒng)故障分析計(jì)算方法的研究從來(lái)沒(méi)有停止過(guò)。我國(guó)電源點(diǎn)和負(fù)荷中心分布極其不合理,基于這種基本國(guó)情,高壓、特高壓輸電被提上了日程;但出于經(jīng)濟(jì)和方便等角度的考慮,高壓、特高壓輸電線路一般不進(jìn)行換位,這就造成了輸電線路三相參數(shù)的不對(duì)稱。本文介紹了一種運(yùn)用對(duì)稱分量法來(lái)分析計(jì)算三相參數(shù)不對(duì)稱的輸電線路故障的計(jì)算方法,論文從磁鏈的角度出發(fā),將三相阻抗表示為關(guān)于三相電流的關(guān)系式,實(shí)現(xiàn)了輸電線路三相阻抗的解耦。運(yùn)用網(wǎng)絡(luò)等值理論,將三相參數(shù)不對(duì)稱的輸電線路等效變換為發(fā)生了某種類型的斷線故障的三相參數(shù)對(duì)稱的輸電線路,當(dāng)三相參數(shù)不對(duì)稱的輸電線路有故障發(fā)生時(shí),則可以看作是等效變換后的三相參數(shù)對(duì)稱的輸電線路發(fā)生了復(fù)雜故障,對(duì)于復(fù)雜故障的計(jì)算,本文運(yùn)用對(duì)稱分量法結(jié)合口網(wǎng)絡(luò)理論來(lái)進(jìn)行分析計(jì)算�？诰W(wǎng)絡(luò)理論就是把每一個(gè)故障點(diǎn)看作是一個(gè)故障端口,根據(jù)故障端口繪制三序網(wǎng)絡(luò)圖,列寫三序節(jié)點(diǎn)導(dǎo)納矩陣,求逆得到三序阻抗矩陣,根據(jù)三序阻抗矩陣可以得到三序口阻抗口矩陣,列寫三序電壓方程和故障邊界條件方程,聯(lián)立方程求解就可以得到故障時(shí)的電壓電流。三相阻抗是關(guān)于三相電流的表達(dá)式,當(dāng)流過(guò)輸電線路的三相電流發(fā)生改變時(shí)等效三相阻抗也會(huì)發(fā)生改變,對(duì)于輸電線路初始阻抗的計(jì)算,假設(shè)流過(guò)輸電線路的初始電流是三相對(duì)稱的。用初始的輸電線路三相阻抗進(jìn)行故障計(jì)算,可以得到初始的故障電壓和電流;將流過(guò)輸電線路的初始故障電流代回輸電線路三阻抗公式,又可以求得新的輸電線路三相阻抗,從而得到新的輸電線路的正負(fù)零序?qū)Ъ{,從而可以得到新的三序節(jié)點(diǎn)導(dǎo)納矩陣,求逆得到新的三序阻抗矩陣,根據(jù)三序阻抗矩陣可以求得新的三序口阻抗矩陣,列寫新的三序電壓方程和故障邊界條件方程,求解出新的故障電壓電流,重復(fù)以上步驟,直到前后兩次計(jì)算的故障電流的百分誤差不超過(guò)1%;此時(shí),得到的電壓、電流就是輸電線路三相參數(shù)不對(duì)稱發(fā)生故障時(shí)的故障電壓、電流。通過(guò)matlab編程對(duì)本文算法進(jìn)行編程,利用EMTP對(duì)系統(tǒng)模型進(jìn)行仿真,將兩者的結(jié)果進(jìn)行比較,驗(yàn)證本文算法的正確性。
[Abstract]:In the process of power system operation, various kinds of faults will occur, and the analysis and calculation of power system faults play an important role in the planning and design of power system, the analysis of accidents and the setting operation of power system. Therefore, the study of power system fault analysis and calculation methods has never stopped. The distribution of power points and load centers in China is extremely unreasonable. Based on this basic situation, high-voltage and ultra-high voltage transmission lines are put on the agenda. However, for reasons of economy and convenience, high-voltage and ultra-high voltage transmission lines generally do not carry out transposition. This results in the asymmetry of three-phase parameters of transmission lines. In this paper, a method of calculating the fault of transmission lines with asymmetric three-phase parameters by using symmetric component method is introduced. In this paper, the three-phase impedance is expressed as the relation of three-phase current from the point of view of flux linkage. The decoupling of three-phase impedance of transmission line is realized. By using the network equivalence theory, the three-phase transmission line with asymmetric parameters is transformed into a transmission line with a certain type of break-line fault. When the three-phase parameter asymmetric transmission line has a fault, It can be regarded as the complex fault of the transmission line with symmetrical three-phase parameters after equivalent transformation. For the calculation of the complex fault, the symmetric component method combined with the theory of port network is used to analyze and calculate the complex fault. The theory of port network is to treat each fault point as a fault port, draw the three-sequence network diagram according to the fault port, write the three-sequence node admittance matrix, and obtain the three-sequence impedance matrix by inverse. According to the three-sequence impedance matrix, the three-sequence impedance port matrix can be obtained, and the three-sequence voltage equation and the fault boundary condition equation can be set up, and the voltage and current in the fault can be obtained by solving the simultaneous equation. Three-phase impedance is the expression of three-phase current. When the three-phase current of transmission line changes, the equivalent three-phase impedance will also change. Assume that the initial current flowing through the transmission line is three-phase symmetric. The initial fault voltage and current can be obtained by using the initial three-phase impedance of the transmission line, and the three-phase impedance formula of the transmission line can be replaced by the initial fault current flowing through the transmission line, and a new three-phase impedance of the transmission line can be obtained. Thus, the positive and negative zero-sequence admittance of a new transmission line can be obtained, a new three-sequence node admittance matrix can be obtained, a new three-sequence impedance matrix can be obtained by inverse, and a new three-sequence impedance matrix can be obtained according to the three-sequence impedance matrix. Write a new three-sequence voltage equation and a fault boundary condition equation, solve the new fault voltage and current, repeat the above steps until the error of the fault current calculated twice before and after is less than 1 percent; in this case, the resulting voltage, Current is the fault voltage and current when the three-phase parameters of transmission line are not symmetrical. The algorithm is programmed by matlab, the system model is simulated by EMTP, and the results are compared to verify the correctness of the algorithm.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM75

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 傅旭;付覽，

本文編號(hào)：1909158