本文選題：發(fā)電機(jī)定子單相接地 + 選相�。� 參考：《華北電力大學(xué)(北京)》2017年博士論文

【摘要】：發(fā)電機(jī)發(fā)生定子單相接地故障時(shí)可能會(huì)灼傷定子鐵心,甚至進(jìn)一步發(fā)展成更嚴(yán)重的故障。此外,發(fā)電機(jī)組鐵心結(jié)構(gòu)復(fù)雜,鐵心一旦損壞,修復(fù)困難,造成巨大的經(jīng)濟(jì)損失。論文以發(fā)電機(jī)定子繞組單相接地故障為研究對(duì)象,從定子單相接地故障選相、故障定位、雙頻注入式定子接地保護(hù)和選擇性定子接地保護(hù)幾方面進(jìn)行研究。論文的主要工作與創(chuàng)新點(diǎn)如下:論文分析了大型隱極發(fā)電機(jī)的繞組電勢(shì)相位特征,提出了兩種計(jì)及繞組電勢(shì)相位的繞組電勢(shì)表達(dá)式。與傳統(tǒng)的繞組電勢(shì)表達(dá)式相比,所提出的繞組電勢(shì)表達(dá)式計(jì)及了繞組電勢(shì)的相位特性,為研究大型隱極發(fā)電機(jī)定子接地故障時(shí)電氣量的相位特征提供了理論基礎(chǔ)。論文提出了一種基于零序電壓相位特征的選相新方法,提高了高阻接地故障時(shí)選相算法的靈敏度。新的選相算法充分利用了動(dòng)作區(qū)域向順時(shí)針偏轉(zhuǎn)的特征,解決了低電壓選相算法在高阻接地故障時(shí)靈敏度低且可能出現(xiàn)誤選相的問(wèn)題。理論和仿真分析表明:該選相方法適用于各種中性點(diǎn)接地方式,在高阻接地故障時(shí)也可以可靠識(shí)別故障相。論文提出了一種利用零序電壓相位特征計(jì)算過(guò)渡電阻的新方法,進(jìn)而實(shí)現(xiàn)了大型凸極發(fā)電機(jī)的定子單相接地故障定位。準(zhǔn)確計(jì)算出故障時(shí)的過(guò)渡電阻是定子單相接地故障定位的最關(guān)鍵問(wèn)題,論文發(fā)現(xiàn)了大型凸極發(fā)電機(jī)的零序電壓相位與過(guò)渡電阻間的關(guān)系,實(shí)現(xiàn)了僅利用發(fā)電機(jī)的本體故障信號(hào)計(jì)算過(guò)渡電阻。對(duì)所提的故障定位方法進(jìn)行了仿真分析和動(dòng)模測(cè)試,結(jié)果表明:該方法適用于大型凸極發(fā)電機(jī),在各種中性點(diǎn)接地方式下,定位結(jié)果準(zhǔn)確,滿足工程需要。論文指出大型隱極發(fā)電機(jī)的繞組電勢(shì)相位會(huì)影響故障定位的精度,利用發(fā)電機(jī)的本體故障信號(hào)計(jì)算過(guò)渡電阻時(shí)必須考慮繞組電勢(shì)的相位特征。論文計(jì)及了繞組電勢(shì)的相位特征,對(duì)利用零序電壓相位特征和相電壓偏移特征的故障定位方法進(jìn)行了改進(jìn)。對(duì)改進(jìn)前后的故障定位方法進(jìn)行了仿真分析,結(jié)果表明:計(jì)及繞組電勢(shì)相位特征后的定位方法,適用于大型隱極發(fā)電機(jī),在各種中性點(diǎn)接地方式下,定位結(jié)果準(zhǔn)確,高阻接地故障時(shí)同樣滿足要求。論文設(shè)計(jì)了一套雙頻率注入的定子接地保護(hù)方案,注入頻率為20Hz和80Hz。此保護(hù)方案在發(fā)電機(jī)的起停機(jī)過(guò)程中不需要短時(shí)閉鎖,實(shí)現(xiàn)了全過(guò)程的保護(hù)功能。高頻段注入頻率的選取是雙頻率注入的定子接地保護(hù)的重要問(wèn)題,論文從注入式保護(hù)的靈敏度、濾波器參數(shù)設(shè)計(jì)等方面,對(duì)注入式保護(hù)的高頻段注入信號(hào)的頻率取值進(jìn)行研究,確定高頻段的注入頻率選取為80Hz。論文提出了一種基于導(dǎo)納不對(duì)稱(chēng)度參數(shù)的選擇性定子接地保護(hù)新原理,解決了擴(kuò)大單元接線機(jī)組定子接地保護(hù)無(wú)選擇性的問(wèn)題。論文分析了發(fā)電機(jī)定子接地故障時(shí)的導(dǎo)納不對(duì)稱(chēng)度,對(duì)于故障發(fā)電機(jī)其導(dǎo)納不對(duì)稱(chēng)度參數(shù)為“有”,其值大于1,非故障發(fā)電機(jī)其導(dǎo)納不對(duì)稱(chēng)度為“無(wú)”,理論值為0。利用導(dǎo)納不對(duì)稱(chēng)度參數(shù)構(gòu)成的擴(kuò)大單元接線定子接地保護(hù),通過(guò)計(jì)算導(dǎo)納不對(duì)稱(chēng)度的最大值找出故障元件。對(duì)所提出的方法進(jìn)行了仿真分析和動(dòng)模測(cè)試,測(cè)試結(jié)果表明該方法能夠選出故障機(jī)組,靈敏度高。
[Abstract]:When the generator stator single-phase grounding fault occurs, it may burn the stator core and even further develop into a more serious fault. In addition, the core structure of the generator is complex, and once the core is damaged, it is difficult to repair and cause huge economic loss. Barrier selection, fault location, dual frequency injection stator grounding protection and selective stator grounding protection are studied. The main work and innovation points of this paper are as follows: the paper analyses the phase characteristics of the windings potential of large sapheno generator, and puts forward two kinds of winding potential expression of the winding potential phase, and the traditional winding electricity. Compared with the potential expressions, the proposed windings potential expression meter and the phase characteristics of the winding potential provide a theoretical basis for the study of the phase characteristics of the electrical quantity of the large sapheno generator stator grounding faults. A new phase selection method based on the zero sequence voltage phase features is proposed to improve the phase selection algorithm for high impedance grounding faults. The new phase selection algorithm makes full use of the characteristics of the movement area to clockwise rotation, and solves the problem of low sensitivity and misselection in high impedance grounding fault. The theory and simulation analysis show that the phase selection method is suitable for various neutral grounding modes and can also be used in high impedance grounding faults. A new method of calculating the transition resistance with zero sequence voltage and phase characteristics is proposed in this paper, and the stator single-phase grounding fault location of the large salient pole generator is realized. The accurate calculation of the transition resistance of the fault is the most important problem of the stator single-phase grounding fault location. The relationship between the zero sequence voltage phase of the machine and the transition resistance is realized, and the transition resistance is calculated only by using the fault signal of the generator. The simulation analysis and dynamic model test are carried out on the proposed fault location method. The results show that the method is suitable for large salient generator, and the positioning results are accurate and satisfied under the grounding mode of various neutral points. The paper points out that the phase of the windings of a large sapheno generator will affect the accuracy of the fault location. The phase characteristics of the winding potential must be taken into consideration when the fault signal is calculated by the generator's fault signal. The phase characteristics of the winding potential are taken into account, and the characteristics of the zero sequence voltage phase and phase voltage offset are used. The fault location method is improved. The simulation analysis of the fault location method before and after the improvement is carried out. The results show that the positioning method after the phase characteristic of the winding potential is suitable for large sapheno generator. The positioning results are accurate and the high impedance grounding fault meets the requirements. The stator grounding protection scheme with dual frequency injection, the injection frequency is 20Hz and 80Hz., the protection scheme does not need short time locking during the starting and stopping process of the generator. The protection function of the whole process is realized. The selection of high frequency injection frequency is the important problem of the stator grounding protection with dual frequency injection. The sensitivity of injection protection and filter are filtered. In the design of the parameter of the wave device, the frequency value of the high frequency injection signal of the injection protection is studied. It is determined that the injection frequency of the high frequency section is selected as the 80Hz. paper, and a new principle of selective stator grounding protection based on the admittance asymmetry parameter is proposed, which solves the non selectivity of the stator grounding protection of the extended unit connection unit. In this paper, the admittance asymmetry of generator stator grounding fault is analyzed, and the admittance asymmetry parameter of the fault generator is "there", its value is more than 1, the admittance asymmetry degree of the non fault generator is "no", and the theoretical value is 0. of the extended unit connection stator grounding protection, which is made up of admittance asymmetry parameter. The maximum value of the admittance asymmetry is calculated to find the fault element. The simulation analysis and dynamic model test are carried out on the proposed method. The test results show that the method can select the fault unit with high sensitivity.
【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TM31

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本文編號(hào)：2061163