本文選題：交流非對稱故障 + 直流控制系統(tǒng)�。� 參考：《華北電力大學(xué)(北京)》2017年碩士論文

【摘要】：隨著直流輸電技術(shù)的發(fā)展,直流系統(tǒng)的輸送功率進(jìn)一步提升。直流輸電線路的增加也帶來了更多換相失敗的問題。因此能否正確的認(rèn)識換相失敗的問題,并能對其加以預(yù)測和判斷成為一個(gè)亟待解決的問題。目前已經(jīng)有很多專家學(xué)者對該問題展開了研究,現(xiàn)階段研究發(fā)現(xiàn),當(dāng)交流系統(tǒng)發(fā)生非對稱故障時(shí),換流器的換相失敗發(fā)生情況具有很強(qiáng)的隨機(jī)性,不但取決于故障的類型,更與故障發(fā)生的時(shí)刻有關(guān)。此外通過對直流輸電系統(tǒng)的仿真分析還發(fā)現(xiàn),由于逆變側(cè)相串聯(lián)的換流器接入連接組別不同的換流變壓器,導(dǎo)致?lián)Q流器發(fā)生的換相失敗的情況也有所不同。為了全面的分析直流的換相失敗問題,對于本文的研究主要考慮了如下三個(gè)方面。首先,換相失敗的問題受交流系統(tǒng)發(fā)生非對稱的故障時(shí)刻影響,不同的故障時(shí)刻對發(fā)生換相失敗的臨界阻抗影響很大。本文利用換相面積的概念對此問題進(jìn)行了詳細(xì)的分析,并且在進(jìn)行仿真分析時(shí)著重注意了故障發(fā)生時(shí)刻對換相失敗造成的影響。其次,本文對換相失敗的產(chǎn)生機(jī)理進(jìn)行了詳細(xì)的分析,并重點(diǎn)分析了換流器連接組別不同對換相失敗問題的影響,并通過仿真與分析結(jié)合的方法對故障發(fā)生時(shí)刻影響同一故障點(diǎn)換相失敗發(fā)生概率的問題進(jìn)行了解釋。此外結(jié)合換流閥在交流系統(tǒng)發(fā)生故障的實(shí)際觸發(fā)過程對換相失敗的判據(jù)進(jìn)行了修改,基于該方法為分析解釋造成換相失敗的原因提供參考。最后,分析直流輸電的控制系統(tǒng),目前主流的直流輸電控制系統(tǒng)可分為定熄弧角控制、定直流電壓控制技術(shù)路線兩種。兩種控制系統(tǒng)均在我國直流輸電工程中大量使用,工程實(shí)際經(jīng)驗(yàn)表明兩種控制系統(tǒng)均具有良好的控制響應(yīng)特性,并能在換相失敗后快速恢復(fù)�？刂葡到y(tǒng)在交流系統(tǒng)發(fā)生故障時(shí)通常會采取提前觸發(fā)的策略以避免換相失敗的發(fā)生,本文將結(jié)合兩種控制技術(shù)進(jìn)行詳細(xì)的介紹和分析。
[Abstract]:With the development of DC transmission technology, the transmission power of DC system is further improved.The increase in DC transmission lines also brings more commutation failures.Therefore, whether we can correctly understand the problem of commutation failure and be able to predict and judge it has become an urgent problem to be solved.At present, many experts and scholars have carried out research on this problem. At present, it is found that when asymmetric faults occur in AC system, commuter commutation failure has a strong randomness, which depends not only on the type of fault, but also on the type of commutator.More related to the time when the fault occurred.In addition, through the simulation analysis of HVDC transmission system, it is also found that the commutation failure of the converter is different due to the connection of inverter side phase converter connected to different converters of different transformer groups.In order to analyze the commutation failure of DC, the following three aspects are considered in this paper.Firstly, the commutative failure is affected by the asymmetric fault time of AC system, and the critical impedance of commutation failure is greatly affected by different fault time.In this paper, the concept of commutative area is used to analyze this problem in detail, and the influence of fault occurrence time on commutation failure is emphasized in the simulation analysis.Secondly, the mechanism of commutation failure is analyzed in detail, and the influence of commutator connection group on commutation failure is analyzed in detail.The probability of commutative failure at the same fault point is explained by the method of simulation and analysis.In addition, the criterion of commutation failure is modified in combination with the actual trigger process of commutation valve failure in AC system, which provides a reference for analyzing and explaining the causes of commutation failure.Finally, the control system of HVDC transmission is analyzed. At present, the mainstream HVDC control system can be divided into two kinds: constant arc angle control and constant DC voltage control technology.Both control systems are widely used in HVDC transmission projects in China. Practical engineering experience shows that the two control systems have good control response characteristics and can recover quickly after commutation failure.In order to avoid the commutation failure, the control system usually adopts the strategy of triggering in advance when the AC system fails. This paper will introduce and analyze the two control techniques in detail.
【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM721.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李少華;王秀麗;張愛玲;彭忠;荊雪記;;并聯(lián)換流器高壓直流輸電系統(tǒng)控制策略[J];電力系統(tǒng)自動化;2015年21期

2 夏成軍;梁國開;涂亮;藍(lán)海文;周保榮;;HVDC受端換流站動態(tài)無功功率恢復(fù)特性及控制措施仿真[J];南方電網(wǎng)技術(shù);2015年08期

3 郭龍;劉崇茹;，

本文編號：1743273