本文選題：電力電子變壓器 + 配電網(wǎng)�。� 參考：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：無論是過去的配電網(wǎng)還是如今的智能配電網(wǎng),電壓都是衡量系統(tǒng)穩(wěn)定性與否的非常重要的元素,也就是說對配電網(wǎng)進行無功優(yōu)化是十分重要的。就國內(nèi)的配電網(wǎng)而言,大多數(shù)都是處于無功不足的網(wǎng)絡(luò),所以其網(wǎng)損非常惡劣,這樣大大消耗了國家的財力和物力。現(xiàn)今的配電網(wǎng)越來越復(fù)雜,對其的無功優(yōu)化所選取的方法不能再居于傳統(tǒng)的一系列形式。傳統(tǒng)無功優(yōu)化的幾種方法已經(jīng)很難應(yīng)對現(xiàn)今的復(fù)雜系統(tǒng),面對復(fù)雜問題很容易就收斂到局部最優(yōu)解更有甚者有不收斂的可能性。本文主要以尋找新的算法來針對配電網(wǎng)的無功優(yōu)化問題進行相應(yīng)改進,從而更有效的解決如新復(fù)雜的配電網(wǎng)優(yōu)化問題。降低網(wǎng)損對整個電網(wǎng)而言有著非常重要的意義,不僅是節(jié)省財力和物力,更對社會人文生活提供了更加優(yōu)越的環(huán)境。配電網(wǎng)的主要構(gòu)成有:線路、變壓器、電容器、負(fù)荷等。由這些器件所構(gòu)成的網(wǎng)絡(luò)稱為配電網(wǎng)絡(luò),其中變壓器在輸配電環(huán)節(jié)又是重中之重。對于現(xiàn)今的配電網(wǎng)而言,想要做到無功合理分配基本有這幾種方式:運用調(diào)相機調(diào)節(jié)(發(fā)出和吸收無功,但基本淘汰)、有載調(diào)壓變壓器的分接頭調(diào)壓、小電容器大規(guī)模成組投切系統(tǒng)中、靜止無功補償裝置等等。本文主要針對于有載調(diào)壓變壓器的分接頭調(diào)壓這種無功優(yōu)化手段進行改進分析,主要通過將有載調(diào)壓變壓器(OLTC)替換為新型的電力電子變壓器(EPT),總結(jié)電力電子變壓器的優(yōu)缺點,從而分析替代的可行性。分析配電網(wǎng)首要就是潮流計算,不改變系統(tǒng)運行的前提下通過潮流計算可對各個節(jié)點的電壓情況、各個支路分布功率的情況以及網(wǎng)絡(luò)功率損耗的情況。對于配電網(wǎng)的無功優(yōu)化問題,提出新的改進后的遺傳算法,其應(yīng)對現(xiàn)今復(fù)雜配電網(wǎng)的能力尤為突出,并予以實例分析證明其可行性。針對配電網(wǎng)無功優(yōu)化問題改進的遺傳算法全局搜索能力強,速度迅捷,可更為有效的搜尋到最優(yōu)解。將改進的遺傳算法應(yīng)用于配電網(wǎng)的無功優(yōu)化中,在配電系統(tǒng)中用EPT代替OLTC后,對某市的實際電網(wǎng)算例進行無功優(yōu)化,并且對比了含有傳統(tǒng)有載調(diào)壓變壓器的配電網(wǎng)的優(yōu)化和含有電力電子變壓器的配電網(wǎng)的優(yōu)化。系統(tǒng)受到小擾動時對簡化的兩節(jié)點系統(tǒng)做仿真實驗,通過分析仿真結(jié)果證明電力電子變壓器可提高系統(tǒng)穩(wěn)定性。
[Abstract]:Whether in the past or today, voltage is a very important element to measure the stability of the distribution network, that is to say, reactive power optimization is very important. As far as the domestic distribution network is concerned, most of them are in the network with insufficient reactive power, so the network loss is very bad, which consumes the national financial and material resources greatly. Nowadays, the distribution network is becoming more and more complex, and the method of reactive power optimization can no longer live in a series of traditional forms. Several traditional reactive power optimization methods have been difficult to cope with the current complex systems. In the face of complex problems, it is easy to converge to the local optimal solution and even have the possibility of non-convergence. In this paper, a new algorithm is found to improve the reactive power optimization problem of distribution network, so as to solve the new complex distribution network optimization problem more effectively. Reducing network loss is of great significance to the whole power network, not only to save financial and material resources, but also to provide a better environment for social and human life. The main components of the distribution network are: lines, transformers, capacitors, loads and so on. The network composed of these devices is called distribution network, in which transformers are the most important in transmission and distribution. For today's distribution network, there are several ways to achieve rational distribution of reactive power: adjusting (emitting and absorbing reactive power, but basically eliminating) by using a camera, adjusting voltage by tap of on-load voltage regulating transformer, In the large-scale group switching system of small capacitors, static var compensator and so on. This paper mainly focuses on the improvement and analysis of tap regulator of on-load voltage regulating transformer, and summarizes the advantages and disadvantages of power electronic transformer by replacing OLTC with a new type of power electronic transformer (EPT). Thus, the feasibility of substitution is analyzed. The power flow calculation is the most important part of the distribution network. Without changing the operation of the system, the voltage of each node, the distribution power of each branch and the power loss of the network can be calculated by power flow calculation. For the reactive power optimization problem of distribution network, a new improved genetic algorithm is proposed, which is especially capable of dealing with complex distribution network, and its feasibility is proved by an example. The improved genetic algorithm (GA) for reactive power optimization problem of distribution network has strong global search ability and fast speed, and can search the optimal solution more effectively. The improved genetic algorithm is applied to the reactive power optimization of the distribution network. After replacing OLTC with EPT in the distribution system, the reactive power optimization is carried out for the actual power network in a certain city. The optimization of the distribution network with the traditional on-load voltage regulating transformer and the distribution network with the power electronic transformer are compared. The simplified two-node system is simulated when the system is subjected to small disturbance. The simulation results show that power electronic transformer can improve the stability of the system.
【學(xué)位授予單位】：沈陽農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM714.3
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本文編號：2101157