【摘要】：當前,電網(wǎng)結構隨著電力系統(tǒng)的發(fā)展而日趨復雜,配電網(wǎng)供電質量直接影響電力網(wǎng)絡安全穩(wěn)定經(jīng)濟運行,因此如何向電力用戶提供高質量電能并合理提高電網(wǎng)經(jīng)濟效益已是擺在電力系統(tǒng)面前的一個重要問題。大部分地區(qū)電網(wǎng)針對因負荷變化引起的電壓偏移問題,采用無功補償就地平衡的原則進行電網(wǎng)無功優(yōu)化,但由于配電網(wǎng)負荷波動性較大,此種方式無法實現(xiàn)全網(wǎng)整體協(xié)調且在有載調壓時容易導致電網(wǎng)震蕩,從而造成高峰負荷時電網(wǎng)末端電壓很低,夜間和低谷負荷時系統(tǒng)電壓偏高,電網(wǎng)鐵損急劇上升。因此,一個以調壓與并聯(lián)電容器補償相結合的節(jié)能措施已被人們所關注。論文提出在無功補償就地平衡的前提下,以提高電壓質量、節(jié)約電網(wǎng)電能、降低電網(wǎng)損耗為目標,對整個配電網(wǎng)絡合理采用有載逆調壓技術并進行研究,根據(jù)負荷變化,以全網(wǎng)損耗最小為原則,對電網(wǎng)中主變壓器采用有載逆調壓技術合理選擇調壓級別,改進了以往文獻單獨強調變壓器經(jīng)濟運行的局限性。配電網(wǎng)實際運行過程中,由于配電線路和配電變壓器負荷系數(shù)不一致,造成利用等值電阻法計算線損誤差過大。針對此問題,論文對等值電阻法進行改進,以配電變壓器運行參數(shù)及額定容量、配電線路參數(shù)、配電變壓器及配電線路中的電量為基礎,計算線損,提高了計算精度,為配電網(wǎng)降損節(jié)能實例分析奠定了基礎。論文以沈陽東民變電站實際運行參數(shù)為例,通過對數(shù)據(jù)進行比較進而分析東民變電站的經(jīng)濟電壓級別,結果表明:負載率升高帶動各線路有功損耗及總損耗升高,與功率損耗最小相對應的經(jīng)濟電壓也隨之增加;在調壓過程中,應重點考慮變電站各支路變壓器的數(shù)量和輸電線路的長度這兩個因素;合理使用有載逆調壓技術,采用經(jīng)濟運行方式,可保證電壓穩(wěn)定性,提高配電網(wǎng)整體經(jīng)濟效益。因此,主變壓器有載逆調壓技術的使用,顯著提高了電壓合格率,降低了電網(wǎng)的有功功率損耗,達到了全網(wǎng)協(xié)調節(jié)能降損的目的。為電網(wǎng)的安全穩(wěn)定的運行提供了保證,也給國民生活帶來了不可小視的社會意義及經(jīng)濟效益。
[Abstract]:At present, the power network structure is becoming more and more complex with the development of the power system. The power supply quality of the distribution network directly affects the security, stability and economic operation of the power network. Therefore, how to provide high quality electric energy to power users and how to improve the economic benefits of power system is an important problem in front of the power system. In order to solve the problem of voltage offset caused by load variation, reactive power optimization is carried out by using the principle of local balance of reactive power compensation, but the load fluctuation of distribution network is large. This method can not realize the overall coordination of the whole network and can easily lead to power grid oscillation when there is load voltage regulation, which results in low terminal voltage at peak load, high system voltage at night and low load, and a sharp rise in iron loss. Therefore, an energy-saving measure combining voltage regulation and shunt capacitor compensation has been paid attention to. Under the premise of local balance of reactive power compensation, aiming at improving voltage quality, saving electric energy and reducing power loss, this paper adopts the technology of load inverse voltage regulation in the whole distribution network reasonably and studies it according to the load variation. Based on the principle of minimum loss of the whole network, the load inverse voltage regulation technology is used to select the voltage regulation grade reasonably for the main transformer in the power network, which improves the limitation of the previous literature that only emphasizes the economic operation of the transformer. In the actual operation of distribution network, because the load coefficient of distribution line and transformer is not consistent, the error of calculating line loss by using equivalent resistance method is too large. In order to solve this problem, the paper improves the equivalent resistance method, based on the operation parameters and rated capacity of distribution transformer, the parameters of distribution line, and the quantity of electricity in distribution transformer and distribution line, the line loss is calculated and the calculation precision is improved. It lays a foundation for example analysis of reducing loss and saving energy in distribution network. Taking the actual operation parameters of Dongmin substation in Shenyang as an example, the economic voltage level of Dongmin substation is analyzed by comparing the data. The results show that the increase of load ratio leads to the increase of active power loss and total loss of each line. The economic voltage corresponding to the minimum power loss also increases. In the process of voltage regulation, two factors, the number of transformer branches in substation and the length of transmission line, should be taken into account. The application of economic operation mode can guarantee voltage stability and improve the overall economic benefit of distribution network. Therefore, the application of on-load inverse voltage regulation technology of main transformer can significantly improve the qualified rate of voltage, reduce the active power loss of the power network, and achieve the goal of coordinated energy saving and loss reduction of the whole network. It not only guarantees the safe and stable operation of the power grid, but also brings the social significance and economic benefit to the national life.
【學位授予單位】：沈陽農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM714.3
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本文編號：2224674