本文關(guān)鍵詞：桂林城區(qū)配電網(wǎng)合環(huán)轉(zhuǎn)負(fù)荷分析與對策研究　出處：《廣西大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 配電網(wǎng) 合環(huán)轉(zhuǎn)負(fù)荷 潮流分析 對策

【摘要】：隨著現(xiàn)代電網(wǎng)迅速發(fā)展,配電網(wǎng)的自動化、智能化進(jìn)程也不斷加快。智能配電要求配電高度自動化,配電網(wǎng)智能調(diào)度。為了提高供電可靠性,我國城市10kV配電網(wǎng)在進(jìn)行設(shè)備停電檢修、線路故障處理及負(fù)荷轉(zhuǎn)移時,通常采用合環(huán)操作的模式。而在合環(huán)操作過程中,不同220kV變電站的10kV配網(wǎng)進(jìn)行帶電合環(huán)操作過程中,配網(wǎng)合環(huán)前兩端母線的電壓幅值差及其相位差通常很大,通常在合環(huán)操作后伴有較大的合環(huán)電流產(chǎn)生,致使10kV饋線保護(hù)裝置動作,同時配網(wǎng)沖擊電流過大對電力設(shè)備也可能造成極大的危害,大大降低電網(wǎng)供電的可靠性。為提高合環(huán)操作成功率及其供電的可靠性與安全性,將合環(huán)調(diào)控與配電網(wǎng)自動化相結(jié)合,以智能化代替人工操作,提供合環(huán)操作效率,降低勞動強(qiáng)度,因此對220kV變電站的10kV帶電合環(huán)轉(zhuǎn)電這一問題的探索有著重要的意義。本文重點對配網(wǎng)合環(huán)方式的類型及其合環(huán)操作運行條件進(jìn)行介紹,分別針對合環(huán)的暫態(tài)與穩(wěn)態(tài)過程進(jìn)行理論分析。構(gòu)建對合環(huán)穩(wěn)態(tài)潮流進(jìn)行求解的等值模型,為減少計算量將多節(jié)點支路等效為單節(jié)點支路。采用疊加法計算原理,推導(dǎo)了合環(huán)穩(wěn)態(tài)電流的計算公式,分析了各個因素對合環(huán)穩(wěn)態(tài)電流的影響。其次對合環(huán)沖擊電流產(chǎn)生進(jìn)行詳細(xì)的分析,構(gòu)建了求解沖擊電流及其過電壓的計算模型,運用PSCAD/EMTDC對合環(huán)的暫態(tài)過程進(jìn)行量化。對桂林城區(qū)10kV配網(wǎng)不同運行方式下的合環(huán)點電壓差、等值阻抗進(jìn)行分析,運用BPA電力系統(tǒng)仿真計算軟件分析了配網(wǎng)不同方式下合環(huán)前后的潮流大小各種參數(shù)的分布情況,通過仿真計算及其經(jīng)驗總結(jié),分析了合環(huán)點電壓差、合環(huán)等值阻抗及其配網(wǎng)負(fù)荷大小對桂林10kV配網(wǎng)合環(huán)成功率的影響。結(jié)合前述的理論研究以及城區(qū)合環(huán)操作經(jīng)驗總結(jié),提出了設(shè)置合理的合環(huán)方式、調(diào)節(jié)變壓器分接頭,控制饋線載流量以及選擇合適的合環(huán)操作時機(jī)等提高合環(huán)轉(zhuǎn)負(fù)荷成功率的有效對策。通過對桂林城區(qū)10kV配網(wǎng)合環(huán)問題的深入研究,在城區(qū)配網(wǎng)今后的合環(huán)操作時有了可靠的理論指導(dǎo),擺脫了以往僅僅依靠調(diào)度人員的經(jīng)驗完成合環(huán)操作的困境,提高了電網(wǎng)供電可靠性。
[Abstract]:With the rapid development of modern power grid, distribution network automation, intelligent process is also accelerating. Intelligent distribution requires distribution high automation, distribution network intelligent dispatch. In order to improve the reliability of power supply. In the urban 10kV distribution network of our country, when carrying on the equipment outage maintenance, the line fault treatment and the load transfer, usually adopts the closed loop operation mode, but in the closing ring operation process. The voltage amplitude difference and phase difference between the two ends of the bus in front of the distribution ring are usually very large during the operation of the 10 kV distribution network in different 220 kV substations. Usually, after the operation of the closed loop, a large current is generated, which results in the operation of the 10 kV feeder protection device, and the excessive impact current of the distribution network may also cause great harm to the power equipment. The reliability of power supply is greatly reduced. In order to improve the success rate of closed loop operation and the reliability and safety of power supply, the closed loop control is combined with distribution network automation to replace manual operation intelligently. Provide ring closing operation efficiency, reduce labor intensity. Therefore, it is of great significance to explore the conversion problem of 10 kV live closing ring in 220 kV substation. This paper mainly introduces the type of distribution network closing ring and its operating conditions. The theoretical analysis of transient and steady state processes of closed loop is carried out, and an equivalent model for solving involutive loop steady state power flow is constructed. In order to reduce the amount of calculation, the multi-node branch is equivalent to the single-node branch. The formula for calculating the steady current of closed loop is derived by using the superposition method. The influence of various factors on the steady current of involute ring is analyzed. Secondly, the generation of impulse current of involutive ring is analyzed in detail, and the calculation model for solving the impulse current and its overvoltage is constructed. The transient process of the PSCAD/EMTDC involute ring is quantified. The voltage difference and equivalent impedance of the closed ring point under different operation modes of 10kV distribution network in Guilin city are analyzed. The distribution of various parameters of power flow before and after closing loop in different modes of distribution network is analyzed by using BPA power system simulation software. Through simulation calculation and experience summarization, the voltage difference of combined ring point is analyzed. The influence of equivalent impedance and distribution load on the success rate of 10 kV distribution ring in Guilin. Based on the theoretical study and the summary of operation experience in urban area, a reasonable closing mode is put forward. The effective countermeasures such as adjusting transformer tap, controlling feeder carrier flow and selecting suitable operation time of closing ring to improve the success rate of closed loop transfer are discussed. Through the in-depth study of 10kV distribution network closing ring problem in Guilin urban area. In the future, there is a reliable theoretical guide for the closed loop operation of urban distribution network, which gets rid of the predicament of only relying on the experience of dispatcher to complete the closed loop operation, and improves the reliability of power supply in the power network.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TM714
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本文編號：1372578