【摘要】：可再生能源的大規(guī)模接入以及能源資源和消費(fèi)分布不均衡問題對電網(wǎng)的資源配置能力提出了緊迫要求,可實(shí)現(xiàn)多電源供電及多落點(diǎn)受電的多端直流輸電(Multi-terminal Direct Current,MTDC)系統(tǒng)在新能源并網(wǎng)及輸送領(lǐng)域應(yīng)用前景廣闊。相對傳統(tǒng)直流輸電而言,柔性直流輸電(Voltage Source Converter based High Voltage Direct Current,VSC-HVDC)技術(shù)具有有功和無功獨(dú)立控制、可以向無源負(fù)荷供電、不需要裝設(shè)無功補(bǔ)償設(shè)備以及濾波裝置、潮流翻轉(zhuǎn)時保持電壓極性不變等優(yōu)勢,因此更適于構(gòu)建MTDC系統(tǒng),即建設(shè)多端柔性直流輸電(Voltage Source Converter based Multi-terminal Direct Current,VSC-MTDC)系統(tǒng)。目前,全球至少已投運(yùn)24條VSC-HVDC工程,其中大多數(shù)是兩端直流輸電工程,VSC-MTDC系統(tǒng)和直流電網(wǎng)正處于起始發(fā)展階段,直流側(cè)故障處理能力是限制VSC-MTDC電網(wǎng)發(fā)展的重要因素之一。針對VSC-MTDC電網(wǎng),本文開展直流輸電線路和直流母線保護(hù)的研究,所做的工作和取得的成果如下:其一,提出基于電流行波極性比較的VSC-MTDC電網(wǎng)直流線路保護(hù)方法。論文首先分析了直流電網(wǎng)中直流線路區(qū)內(nèi)外故障時線路兩端的初始電流行波極性特征:1)當(dāng)某正極線路故障時,包括正極接地和正負(fù)極間故障,故障的正極線路兩端的初始電流行波極性相同,并且同為正極性;其他非故障正極線路兩端的極性相反或者同為負(fù)極性。2)當(dāng)某負(fù)極線路故障時,包括負(fù)極接地和正負(fù)極間故障,故障的負(fù)極線路兩端的初始電流行波極性相同,并且同為負(fù)極性;其他非故障負(fù)極線路兩端的極性相反或者同為正極性。然后,利用上述區(qū)內(nèi)外故障時的極性特征差異,構(gòu)造了直流輸電線路保護(hù)判據(jù),并根據(jù)小波變換的相關(guān)理論對初始電流行波的極性進(jìn)行提取。此外,論文分析了在電磁耦合作用下故障極對非故障極的影響,提出了基于電流行波小波變換模極大值的幅值關(guān)系識別直流線路故障類型的方法。其二,提出基于采樣值差動電流的VSC-MTDC電網(wǎng)直流母線保護(hù)方法。論文分析了直流電網(wǎng)中直流母線區(qū)內(nèi)外故障時與母線相連各支路的電流采樣值之和(采樣值差動電流)的幅值特征:外部故障或正常運(yùn)行狀態(tài)下,母線的采樣值差動電流是零,內(nèi)部短路故障時,采樣值差動電流等于各直流線路的短路電流瞬時值的總和,其值非常大。利用母線采樣值差動電流在區(qū)內(nèi)外故障時的幅值差異,論文構(gòu)造了 VSC-MTDC電網(wǎng)直流母線保護(hù)判據(jù)。其三,通過在每個換流站直流側(cè)出口處的正極和負(fù)極線路上串聯(lián)電阻型超導(dǎo)故障限流器,將直流側(cè)故障電流限制在一定范圍內(nèi),與所提保護(hù)方法相配合,用開斷容量較小的直流斷路器開斷故障電流,實(shí)現(xiàn)故障母線或線路的隔離。最后,利用PSCAD電磁暫態(tài)仿真軟件搭建了采用兩電平換流器的±200kV四端柔性直流電網(wǎng)模型,并利用該模型對所提保護(hù)方案進(jìn)行了大量仿真。仿真結(jié)果表明,對于不同故障初始條件下的VSC-MTDC電網(wǎng)直流側(cè)短路故障,保護(hù)均能做出正確判斷,動作速度快,可靠性高,可以耐受一定過渡電阻。
[Abstract]:The large-scale access of renewable energy and the unbalanced distribution of energy resources and consumption have put forward urgent requirements for the power distribution capability of the power grid. The Multi-terminal Direct Current (MTDC) system with multi power supply and multi drop point receiving is widely used in the field of new energy source grid connection and transportation. For HVDC, Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) technology has active and reactive power independent control, which can supply power to passive load, do not install reactive power compensation equipment and filter device, and keep the voltage polarity constant when the power flow is turned over, so it is more suitable for construction. MTDC system, namely, the construction of Voltage Source Converter based Multi-terminal Direct Current, VSC-MTDC system. At present, at least 24 VSC-HVDC projects have been delivered in the world, most of which are two terminal DC transmission projects, VSC-MTDC system and direct current network are in the initial stage of development, DC side fault handling capacity It is one of the important factors to restrict the development of VSC-MTDC power grid. Aiming at VSC-MTDC power grid, the research on DC transmission line and DC bus protection is carried out in this paper. The work and achievements are as follows: first, a DC line protection method based on the comparison of current traveling wave polarity is proposed in the VSC-MTDC power grid. The initial electric wave polarity characteristics of the two ends of the line at both ends of the flow line area: 1) when a positive pole line fault, including the positive pole grounding and the positive and negative pole fault, the initial electric wave polarity of the two ends of the fault positive pole line is the same, and it is positive polarity; the polarity of the two ends of the other non fault positive line is opposite to the polarity or the negative polarity.2). When a negative electrode fault, including the negative electrode grounding and the positive and negative pole fault, the initial electric wave polarity of the two ends of the negative electrode line is the same, and it is negative polarity. The polarity of the other two ends of the non fault negative circuit is opposite or positive polarity. Then, the DC transmission is constructed by using the difference of the polarity characteristic of the fault in the above area and the fault. According to the correlation theory of the wavelet transform, the polarity of the initial current traveling wave is extracted. In addition, the paper analyzes the influence of the fault pole to the non fault pole under the electromagnetic coupling, and puts forward a method to identify the fault type of the DC line based on the amplitude relation of the maximum value of the current traveling wave wavelet transform. A DC bus protection method for VSC-MTDC power grid based on sampled value differential current is presented. The paper analyses the amplitude characteristics of the sum of current sampling values of each branch connected to the bus line connected to the busbar when the internal and external faults of the DC power grid are inside and outside the DC bus zone. The differential current of the sample value of the bus is zero under the external fault or the normal state of operation. In the case of short circuit fault, the differential current of sampling value equals the sum of the short-circuit current of each DC line, and its value is very large. Using the difference of the amplitude of the differential current of the bus line sampling value, the DC bus protection criterion of the VSC-MTDC power grid is constructed. The series resistance superconducting fault current limiter on the pole line limits the fault current of the DC side to a certain range, cooperates with the proposed protection method, disconnects the fault current with the DC circuit breaker with small open capacity, and realizes the isolation of the fault bus or line. Finally, the two level converter is set up by using the PSCAD electromagnetically transient simulation software. The model of 200kV four terminal flexible DC power grid is used to simulate the proposed protection scheme with this model. The simulation results show that the protection can make the correct judgment for the short circuit fault of the VSC-MTDC power grid under the initial conditions of different faults. The action speed is fast, the reliability is high, and a certain transition resistance can be tolerated.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM721.1

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ;我國首次建設(shè)750kV電網(wǎng)工程[J];東北電力技術(shù);2003年04期

2 趙勤;;加快電網(wǎng)建設(shè) 促進(jìn)科學(xué)發(fā)展[J];中共樂山市委黨校學(xué)報;2009年03期

3 徐昌平;;工程量清單計價在電網(wǎng)工程中的應(yīng)用研究[J];廣東科技;2012年21期

4 顧平和;;防衛(wèi)電網(wǎng)工程簡介和改進(jìn)[J];建筑電氣;1985年02期

5 韓豐;;電網(wǎng)建設(shè):發(fā)展思路與區(qū)域布局[J];中國電力企業(yè)管理;2006年Z1期

6 楊宗屏;;電網(wǎng)建設(shè)如何突破困境[J];中國電力企業(yè)管理;2006年Z1期

7 葛雷;;溫州電網(wǎng)建設(shè)期待提速[J];浙江經(jīng)濟(jì);2006年13期

8 張雙萍;;淺談電網(wǎng)建設(shè)項(xiàng)目經(jīng)濟(jì)評價的編制[J];廣西電業(yè);2006年09期

9 趙玉鑲;;電網(wǎng)建設(shè):遭遇通道之困[J];國家電網(wǎng);2006年04期

10 徐聲福;馬建麗;;創(chuàng)新助推“綠色”電網(wǎng)建設(shè)[J];云南電業(yè);2007年03期

相關(guān)會議論文 前10條

1 江水生;;電網(wǎng)建設(shè)外部環(huán)境問題分析及對策[A];2009年電力設(shè)施保護(hù)工作交流大會論文集[C];2009年

2 公茂獎;王俊增;孫玉欣;;電網(wǎng)工程施工企業(yè)在高原地區(qū)電網(wǎng)工程建設(shè)階段的成本控制11點(diǎn)措施[A];2014年2月建筑科技與管理學(xué)術(shù)交流會論文集[C];2014年

3 楊靜;;對縣城電網(wǎng)改造的技術(shù)的建議和措施[A];廣西電機(jī)工程學(xué)會第九屆青年學(xué)術(shù)論壇論文集[C];2006年

4 凌征仲;;云南電網(wǎng)電力社會普遍服務(wù)的目標(biāo)與途徑[A];2007云南電力技術(shù)論壇論文集[C];2007年

5 黃蓉;;西部電網(wǎng)配置滯后 新能源發(fā)展遇困局[A];中國風(fēng)電(2013年09月)[C];2013年

6 楊宗屏;;論述降低電網(wǎng)工程造價[A];浙江電力科學(xué)發(fā)展[C];2005年

7 鄭燕;崔萬福;;電網(wǎng)工程技術(shù)經(jīng)濟(jì)仿真關(guān)鍵技術(shù)[A];電網(wǎng)工程造價管理優(yōu)秀論文[C];2011年

8 張勇;;電網(wǎng)企業(yè)資產(chǎn)管理外部環(huán)境影響因素分析[A];第十二屆中國管理科學(xué)學(xué)術(shù)年會論文集[C];2010年

9 ;新建電源接入電網(wǎng)監(jiān)管暫行辦法[A];中國農(nóng)機(jī)工業(yè)協(xié)會風(fēng)能設(shè)備分會《風(fēng)能產(chǎn)業(yè)》（2014年第3期）[C];2014年

10 喬淑芳;荀志遠(yuǎn);索亮;;QFD方法在電網(wǎng)工程設(shè)計中的應(yīng)用[A];第十一屆中國管理科學(xué)學(xué)術(shù)年會論文集[C];2009年

相關(guān)重要報紙文章 前10條

1 王震邋班永威;我市縣城電網(wǎng)建設(shè)與改造工程順利通過省級驗(yàn)收[N];駐馬店日報;2007年

2 國家電力公司華中公司 桂衡;政府監(jiān)管下電網(wǎng)建設(shè)投融資態(tài)勢[N];中國電力報;2003年

3 本報記者 王拉田;十大電網(wǎng)工程進(jìn)展順利[N];寶雞日報;2006年

4 記者 劉輝;電監(jiān)會通報電網(wǎng)安全檢查情況[N];中國電力報;2006年

5 董玉平;電網(wǎng)崛起 光耀戈壁[N];國家電網(wǎng)報;2007年

6 林光華;電網(wǎng)與電源協(xié)調(diào)發(fā)展[N];華東電力報;2007年

7 記者 何迪 通訊員 李旭東;我市縣城電網(wǎng)工程通過省發(fā)改委驗(yàn)收[N];孝感日報;2007年

8 記者 孔慧邋見習(xí)記者 羅非;今年全市電網(wǎng)建設(shè)將投資10億元[N];商丘日報;2008年

9 李志浩邋張小，

本文編號：2156042