本文關(guān)鍵詞：變壓器差動保護的研究與改進　出處：《華北電力大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 變壓器 差動保護 EMD+ETO 電子型電流互感器

【摘要】：隨著我國電力的不斷發(fā)展與進步,特高壓輸電線路的不斷建設(shè)、超大容量機組不斷增加、區(qū)域之間的電網(wǎng)互聯(lián)的時代已經(jīng)逐步實現(xiàn),目前電網(wǎng)的復(fù)雜度也逐步加深,并且規(guī)模不斷擴大,對電力系統(tǒng)的安全運行提出了新的要求。 變壓器作為電力系統(tǒng)中最重要的電氣設(shè)備之一,在電網(wǎng)中承載著電力搬運工的角色,提高變壓器保護的靈敏性與可靠性顯得尤為重要。但是相對于母線等其它一次性設(shè)備而言,變壓器保護的誤動次數(shù)統(tǒng)計一直處于一個比較高的水平,并且隨著電子式互感器在智能電站工程上的逐步使用,這給變壓器保護帶來了新的研究思路,特別是變壓器差動保護的研究提出了新的方向。 本文詳細闡述了變壓器差動保護的研究現(xiàn)狀,對國內(nèi)外的涌流識別的新原理、新方法進行了優(yōu)缺點分析。理論分析了變壓器勵磁涌流、變壓器恢復(fù)性涌流以及和應(yīng)涌流形成的機理,做出了詳細的理論推導(dǎo),進一步詳細分析了其影響因素。 在理論分析的基礎(chǔ)上采用MATLAB軟件中Simulink模塊對變壓器的三種涌流分別進行了建模仿真。仿真結(jié)果展示了合閘角、線路故障切除對變壓器勵磁涌流的影響；而后,分析了變壓器并聯(lián)以及串聯(lián)情況下和應(yīng)涌流的形成過程并且得出系統(tǒng)電阻越大越容易造成變壓器和應(yīng)涌流的形成。通過以上分析發(fā)現(xiàn)必須采取一定的措施對變壓器各種故障進行辨識以防止其保護誤動而影響電力系統(tǒng)的穩(wěn)定運行,接著介紹了EMD+TEO實現(xiàn)涌流與內(nèi)部故障的辨別,進而實現(xiàn)涌流時閉鎖差動保護,此種辦法能夠?qū)ψ儔浩鞲鞣N故障狀態(tài)實現(xiàn)很好的辨識從而確保系統(tǒng)正常情況下的穩(wěn)定運行。 最后本文采用PSCAD軟件構(gòu)建了三繞組變壓器電流差動保護仿真系統(tǒng),并建立了變壓器區(qū)內(nèi)和區(qū)外故障仿真模型以及傳統(tǒng)電流互感器和電子式電流互感器(ECT)仿真模型。通過對變壓器區(qū)外、區(qū)內(nèi)短路故障的仿真分析傳統(tǒng)CT和ECT在傳統(tǒng)比率制動特性的差動保護中的動作軌跡和動作出口。根據(jù)仿真結(jié)果,改進了傳統(tǒng)變壓器差動保護在ECT運用中整定原則和整定定值方案,在一定程度上解決了智能電站工程中變壓器差動保護的整定問題。
[Abstract]:With the development and progress of our country ' s electric power , the construction of extra - high voltage transmission line , the increasing of super - large capacity unit , the time of grid interconnection between the regions has been gradually realized , and the complexity of the power grid is gradually deepened , and the scale is continuously expanding , and the new requirements for the safe operation of the power system are put forward . As one of the most important electrical equipment in power system , the transformer is the most important electrical equipment in power system . It is very important to improve the sensitivity and reliability of transformer protection . However , in the case of other disposable equipment such as bus and so on , the error number of transformer protection has always been at a relatively high level , and with the gradual use of electronic mutual inductor in the engineering of intelligent power station , this brings new research thinking to the protection of transformer , especially the research of transformer differential protection . In this paper , the current situation of transformer differential protection is described in detail , and the new principle and new method of inrush current identification at home and abroad are analyzed . Based on the theory analysis , the simulation results of three kinds of inrush current of transformer are simulated by Simulink module in MATLAB software . The simulation results show the influence of switching angle and line fault removal on the inrush current of transformer . In the end , the current differential protection simulation system of three - winding transformer is constructed by PSCAD software , and the simulation model of transformer area and outer fault is established , and the simulation model of traditional current transformer and electronic current transformer ( ECT ) is established . Through simulation analysis of the short - circuit fault in the area of transformer , the operation locus and action exit of traditional CT and ECT in the differential protection of traditional ratio braking characteristic are analyzed . According to the simulation results , the setting principle and setting value scheme of traditional transformer differential protection in ECT application are improved , and the setting problem of transformer differential protection in intelligent power station engineering is solved to some extent .

【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM774

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本文編號：1435771