【摘要】：直流偏磁作為電力變壓器運(yùn)行時(shí)一個(gè)特殊工況,會(huì)造成電力變壓器出現(xiàn)一系列問題,還會(huì)對(duì)電力系統(tǒng)產(chǎn)生一定影響。其中,變壓器運(yùn)行噪聲的變化是最容易被識(shí)別和發(fā)現(xiàn)的。近幾年,低噪聲變壓器由于其運(yùn)行噪聲低,對(duì)周圍居民正常生活環(huán)境影響小,以及對(duì)變電站選址制約小,特別適合城市繁華地區(qū)使用等原因,越來越受到市場歡迎。隨著大量低噪聲變壓器的投運(yùn),直流入侵對(duì)低噪聲變壓器的影響也越來越受到關(guān)注。本文以國內(nèi)某220kV變電站兩臺(tái)同型降壓低噪聲環(huán)保變壓器在運(yùn)行時(shí),出現(xiàn)了其中一臺(tái)中性點(diǎn)接地的變壓器噪聲突然變大,若斷開此接地點(diǎn),另一臺(tái)中性點(diǎn)接地,則接地的變壓器噪聲同樣變大這一案例作為分析對(duì)象,從現(xiàn)場噪聲試驗(yàn)數(shù)據(jù)和頻譜特征入手,比對(duì)變壓器制造廠原始出廠測(cè)試數(shù)據(jù),并結(jié)合變電站多種運(yùn)行工況下的測(cè)試數(shù)據(jù),分析發(fā)現(xiàn)了這兩臺(tái)的變壓器中性點(diǎn)有微小的直流電流輸入。論文論證了這兩臺(tái)變壓器中性點(diǎn)出現(xiàn)微小直流的可能性,并分析了直流電流的可能來源。首先,本文在論述變壓器的多種鐵心結(jié)構(gòu)形式、空載性能理論依據(jù)和工程計(jì)算過程的基礎(chǔ)上,分析了鐵心材質(zhì)的各項(xiàng)性能和選取關(guān)鍵,從工程制造各個(gè)環(huán)節(jié)論述了造成變壓器噪聲等空載性能異常的可能性,并對(duì)該變壓器生產(chǎn)制造過程中的材料、結(jié)構(gòu)和工藝等進(jìn)行了分析,確認(rèn)了該變壓器的低噪聲性能指標(biāo)。接下來,從變壓器鐵心材料的物理性能和選用,以及變壓器設(shè)計(jì)方案中鐵心設(shè)計(jì)參數(shù)選取等方面探究了中性點(diǎn)輸入微小直流造成低噪聲環(huán)保電力變壓器噪聲異常的可能性,并假設(shè)不同的設(shè)計(jì)參數(shù)和材料選取情況下,計(jì)算出不同性能的變壓器在同樣工況下噪聲的變化量,進(jìn)一步確認(rèn)了設(shè)計(jì)磁通密度較低,材料選用優(yōu)良的變壓器,對(duì)直流的敏感度更高。最后,列舉了直流侵入對(duì)變壓器和電網(wǎng)的其他危害,對(duì)該變壓器的運(yùn)行維護(hù)按照是否消除故障分成兩個(gè)階段提出了建議。第一,直流短期存在期間,變壓器繼續(xù)掛運(yùn)行的維護(hù)和檢修措施;第二,消除直流源或采取隔離措施之后一年時(shí)間內(nèi)變壓器的監(jiān)測(cè)、維護(hù)和檢修措施。依據(jù)此運(yùn)行案例,本文還對(duì)變壓器在工廠制造期間如何實(shí)現(xiàn)低噪聲,從參數(shù)選型、材料選取、設(shè)計(jì)結(jié)構(gòu)、工藝控制等提出了建議。
[Abstract]:As a special condition of power transformer, DC bias magnetic field will cause a series of problems in power transformer, and will also have a certain impact on power system. Among them, the change of transformer operating noise is the most easily recognized and detected. In recent years, the low noise transformer has been more and more popular in the market because of its low operating noise, little influence on the normal living environment of the surrounding residents, and little restriction on the location of the substation, especially suitable for the use in the bustling urban areas. With the operation of a large number of low-noise transformers, the influence of DC intrusion on low-noise transformers has been paid more and more attention. In this paper, during the operation of two homotypic low-noise and low-voltage environmental protection transformers in a domestic 220kV substation, the noise of one of the transformers with neutral grounding suddenly increases. If the connection is disconnected, the other will be grounded. Based on the noise test data and spectrum characteristics, the original test data of transformer factory are compared, and the test data under various operating conditions of substation are combined with the test data. It is found that the neutral point of the two transformers has small DC current input. In this paper, the possibility of micro DC in neutral point of the two transformers is demonstrated, and the possible source of DC current is analyzed. First of all, on the basis of discussing various types of core structure of transformer, theoretical basis of no-load performance and engineering calculation process, this paper analyzes the performance and selection key of core material. The possibility of abnormal no-load performance such as transformer noise is discussed from various aspects of engineering manufacturing. The materials, structure and process in the manufacturing process of the transformer are analyzed, and the low noise performance index of the transformer is confirmed. Then, from the aspects of the physical properties and selection of transformer core materials, and the selection of core design parameters in the transformer design scheme, the possibility of low noise environmental protection transformer noise anomaly caused by small DC input of neutral point is explored. On the assumption of different design parameters and material selection, the variation of noise of transformer with different performance under the same working condition is calculated. It is further confirmed that the design flux density is lower and the material is excellent. The sensitivity to DC is higher. Finally, the other hazards of DC intrusion to transformer and power network are listed, and the operation and maintenance of the transformer is divided into two stages according to whether the fault is eliminated or not. First, the maintenance and repair measures for the transformer to continue to operate during the short period of DC existence; second, the monitoring, maintenance and repair measures for the transformer within one year after the elimination of the DC source or the adoption of isolation measures. According to the operation case, this paper also puts forward some suggestions on how to realize low noise during the manufacturing period of the transformer, including parameter selection, material selection, design structure, process control, etc.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM41

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ;國家發(fā)改委、國家能源局正式發(fā)布《電力發(fā)展“十三五”規(guī)劃》[J];中國核工業(yè);2016年11期

2 張振;;特高壓輸電技術(shù)發(fā)展研究[J];科技風(fēng);2015年13期

3 孫建濤;李金忠;張書琦;劉銳;湯浩;高飛;吳超;鄧俊宇;;單相單柱旁軛變壓器直流偏磁運(yùn)行性能測(cè)試與分析[J];電網(wǎng)技術(shù);2013年07期

4 楊永明;劉行謀;陳濤;楊帆;項(xiàng)丹;;特高壓直流輸電接地極附近的土壤結(jié)構(gòu)對(duì)變壓器直流偏磁的影響[J];電網(wǎng)技術(shù);2012年07期

5 牛春芳;耿榮林;;降低變壓器噪聲方法的探討[J];變壓器;2010年12期

6 李曉萍;文習(xí)山;;三相五柱變壓器直流偏磁計(jì)算研究[J];中國電機(jī)工程學(xué)報(bào);2010年01期

7 劉連光;劉春明;張冰;王澤忠;肖湘寧;韓立章;;中國廣東電網(wǎng)的幾次強(qiáng)磁暴影響事件[J];地球物理學(xué)報(bào);2008年04期

8 郭滿生;劉東升;張喜樂;高中記;李眾祥;郭建貞;;單相三柱電力變壓器振動(dòng)與噪聲特性的試驗(yàn)研究[J];電氣制造;2008年03期

9 曹林;趙杰;何金良;陳水明;;三相三柱變壓器對(duì)偏磁電流的耐受特性研究[J];高電壓技術(shù);2007年03期

10 皇甫成;阮江軍;張宇;王燕;;變壓器直流偏磁的仿真研究及限制措施[J];高電壓技術(shù);2006年09期

相關(guān)博士學(xué)位論文 前3條

1 董霞;變壓器直流偏磁研究[D];山東大學(xué);2013年

2 蒯狄正;電網(wǎng)設(shè)備直流偏磁影響檢測(cè)分析與抑制[D];南京理工大學(xué);2005年

3 姚纓英;大型電力變壓器直流偏磁現(xiàn)象的研究[D];沈陽工業(yè)大學(xué);2000年

，

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