【摘要】：隨著我國經濟的迅速發(fā)展，大氣環(huán)境不斷惡化，近些年來國內各地不斷出現的大霧天氣，嚴重威脅到電力系統的安全穩(wěn)定運行，霧的物理化學特征及霧的狀態(tài)等對輸電線路絕緣子霧閃放電特性及閃絡過程有著重要的影響。目前，國內外研究學者對其研究相對較少�；谝酝难芯砍晒按嬖诘膯栴}，采用試驗研究和理論分析相結合的方式，首先在重慶大學湖南省懷化市雪峰山自然覆冰試驗站對自然霧的物理化學特征進行了測量分析；然后研究了霧中絕緣子表面濕潤受潮過程及其影響因素，最后選取典型的XP-160和LXY4-160懸式絕緣子為試驗研究對象，研究霧中絕緣子交流放電特性。通過分析得到以下結論： (1)自然霧中絕緣子表面濕潤受潮包括水分子冷凝過程和絕緣子表面霧水水滴碰撞過程。水分子冷凝過程是亞穩(wěn)態(tài)的過飽和水蒸汽自發(fā)轉變?yōu)榉�(wěn)態(tài)的液態(tài)水或晶體的過程；通過建模仿真分析了絕緣子表面的水滴碰撞特性，分析了風速和水滴直徑對水滴碰撞系數的影響，得出水滴碰撞系數隨風速和水滴直徑的增大而增大。蒸汽霧中，絕緣子表面濕潤過程主要是冷凝作用；超聲波冷霧中，絕緣子表面濕潤過程主要受到霧水水滴碰撞絕緣子表面的影響。 (2)清潔絕緣子霧閃電壓隨著霧水電導率的增加而逐漸下降，單片清潔XP-160絕緣子霧閃電壓U50與霧水電導率γ20滿足如U50K a20K a20的冪指數形式，其中K=134.65，a=0.158，相關系數R20.97。通過對計算值和試驗結果的對比，兩者相對誤差在5%以內，因此可認為推導擬合的關系式是可行的。 (3)污穢絕緣子霧閃電壓U50隨著霧水電導率γ20的增加而逐漸下降，且具有飽和趨勢。為研究霧水電導率對污穢絕緣子霧閃電壓的影響特性，，定義附加鹽密，污穢絕緣子霧閃電壓可表示為U50A S a，式中為附加鹽密，mg/cm2。附加鹽密與霧水電導率近似成線性關系，可表示成b20c。通過對計算值和試驗結果的對比，兩者相對誤差在7%以內，因此可認為該數學模型是可行的。 (4)霧中絕緣子交流霧閃電壓隨著霧水溫度的升高而逐漸減小。其原因主要是溫度升高，能增大溶液的溶解度，使更多的NaCl溶解；能降低溶液的粘度，使得溶液中離子運動速度的增大。 (5)氣流的吹弧效應對自然霧中絕緣子放電電弧的形態(tài)起主導作用，在局部電弧形成直至閃絡過程中，風速為0~5m時，氣流對自然霧中絕緣子放電電弧形態(tài)的影響較小，可以忽略；風速為10~15m時，氣流對自然霧中絕緣子放電電弧形態(tài)的影響較大，主要表現為電弧直徑的減小，放電電弧成為多分支體。
[Abstract]:With the rapid development of China's economy, the atmospheric environment is getting worse and worse. In recent years, the foggy weather in various parts of the country has seriously threatened the safe and stable operation of the power system. The physical and chemical characteristics of fog and the state of fog have an important influence on the flashover discharge characteristics and flashover process of insulators on transmission lines. At present, the domestic and foreign research scholars to its research is relatively few. Based on the previous research results and existing problems, the physical and chemical characteristics of natural fog were measured and analyzed at Xuefeng Mountain Natural Ice Test Station of Huai Hua City, Hunan Province, Chongqing University by combining experimental research with theoretical analysis. Then, the wetting process of insulator surface in fog and its influencing factors are studied. Finally, typical XP-160 and LXY4-160 suspended insulators are selected as experimental objects to study the AC discharge characteristics of insulators in fog. The main conclusions are as follows: (1) wetting of insulator surface in natural fog includes condensation process of water molecule and collision process of water droplet on insulator surface. The condensation process of water molecules is the process of spontaneous transformation of supersaturated water vapor from metastable state to steady state liquid water or crystal. The characteristics of water droplet collision on insulator surface are analyzed by modeling and simulation. The influence of wind speed and droplet diameter on the impact coefficient of water droplet is analyzed. It is concluded that the impact coefficient of water droplet increases with the increase of wind speed and droplet diameter. In steam fog, the process of wetting insulator surface is mainly condensation; in ultrasonic cold fog, The wetting process of insulator surface is mainly affected by the impact of fog water droplets on the insulator surface. (2) the lightning pressure of clean insulator mist decreases with the increase of fog conductivity. The lightning pressure U50 of monolithic clean XP-160 insulator and the conductivity 緯 20 of foggy water satisfy the power exponent form of U50Ka20Ka20, in which the correlation coefficient is R20.97. By comparing the calculated values with the experimental results, the relative error between them is less than 5%, so it can be considered that the fitting formula is feasible. (3) the lightning pressure U50 of contaminated insulator mist decreases with the increase of fogwater conductivity 緯 20. And the trend of saturation. In order to study the influence of foggy water conductivity on the lightning voltage of contaminated insulators, the additional salt density is defined. The fog flash voltage of polluted insulators can be expressed as U50A sa, and the formula is added salt density / mg / cm 2. The additional salt density is approximately linear to the conductivity of fog water and can be expressed as b20c. By comparing the calculated values with the experimental results, the relative error is less than 7%, so the mathematical model can be considered feasible. (4) the lightning pressure of insulator AC fog in fog decreases with the increase of fog temperature. The main reason is that the increase of temperature can increase the solubility of the solution, make more NaCl dissolve, and reduce the viscosity of the solution. The velocity of ion movement in solution is increased. (5) the arc blowing effect of air flow plays a leading role in the shape of discharge arc of insulator in natural fog. When the local arc is formed until the flashover process, the wind speed is 0 ~ 5 m. The influence of air flow on the discharge arc shape of insulator in natural fog is small, which can be ignored, and when the wind speed is 10 ~ 15m, the influence of air flow on the discharge arc shape of insulator in natural fog is greater, mainly as the decrease of arc diameter. The discharge arc becomes a multi-branched body.
【學位授予單位】：重慶大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM216

【參考文獻】

相關期刊論文 前10條

1 周建瑋;李磊;王詠青;;霧微物理特征的研究進展[J];安徽農業(yè)科學;2009年20期

2 彭中貴;陳桂元;張毅;陳軍;;重慶霧水[J];重慶環(huán)境科學;1992年03期

3 張開賢;懸式絕緣子串自然積污規(guī)律的探討[J];電網技術;1997年03期

4 張志勁;蔣興良;孫才新;;污穢絕緣子閃絡特性研究現狀及展望[J];電網技術;2006年02期

5 林長城;趙衛(wèi)紅;蔡義勇;王祖爐;陳勝偉;;福建九仙山自然保護區(qū)云霧水、雨水的酸度分析[J];福建農林大學學報(自然科學版);2007年06期

6 武利會;王巖;;酸霧對污穢絕緣子的交流電氣特性的影響[J];廣東電力;2006年05期

7 舒立春,孫才新,毛國志,顧樂觀;酸霧中染污絕緣子的交流閃絡特性[J];高電壓技術;1995年03期

8 吳光亞,蔡煒,盧燕龍,肖勇,趙全江,薛春林;直流輸電線路絕緣子串片數的防污設計[J];高電壓技術;2001年06期

9 梅紅偉;毛穎科;卞星明;彭功茂;王黎明;關志成;;相對濕度對絕緣子泄漏電流最大值的影響[J];高電壓技術;2010年03期

10 宿志一;;霧霾天氣對輸變電設備外絕緣的影響[J];電網技術;2013年08期

本文編號：2225720