本文選題：輸電線 + 覆冰��； 參考：《重慶大學(xué)》2014年碩士論文

【摘要】：隨著我國用電負(fù)荷不斷增長，高電壓等級的地下電力電纜以及特高壓輸電線路的建設(shè)在過去幾年快速推進(jìn)。高電壓等級輸電線路因其輸電距離長、輸送容量大，因此交流高壓輸電線路的無功功率的補(bǔ)償對線路的穩(wěn)定運(yùn)行有著重要的意義。當(dāng)架空輸電導(dǎo)線覆冰、地下電力電纜隧道環(huán)境遭受破壞時，輸電線路的等效電參數(shù)將會改變，，在計算分析輸電線路的無功功率時需要考慮輸電線路電參數(shù)的改變。 對于正常運(yùn)行輸電線路，常常采用“路”的方法計算輸電線路的傳輸功率。當(dāng)輸電導(dǎo)線覆冰、地下電力電纜隧道環(huán)境遭受破壞時，由于輸電線路的等效電參數(shù)改變，從“路”的角度計算傳輸功率的復(fù)雜度將提高。 因此論文提出了基于坡印亭矢量的輸電線能量傳輸表征模型，即從“場”的角度計算輸電線路的傳輸功率。首先推導(dǎo)了坡印廷矢量表征電磁能量的數(shù)值表達(dá)式，進(jìn)而基于空間步進(jìn)FDFD法提出了輸電線三維能量傳輸表征模型，模型中提出了帶狀電荷模型計算輸電線路的初始截面電場強(qiáng)度。基于FDFD的三維傳輸能量表征模型能夠計算不規(guī)則覆冰架空輸電線、不規(guī)范敷設(shè)的電纜的功率傳輸情況。 本文運(yùn)用基于坡印亭矢量的輸電線能量傳輸表征模型計算了架空輸電線弧垂及覆冰情況，電纜輸電線介質(zhì)分層情況、偏心情況、電纜溝積水情況的功率傳輸情況。計算結(jié)果表明： （1）弧垂導(dǎo)致輸電線容性無功和感性無功損耗都增加。弧垂最低點(diǎn)處截面，單位長度空間容性無功損耗有較大的增加，感性無功損耗略微減��；導(dǎo)線懸掛點(diǎn)處，單位長度容性和感性無功損耗略微增加。 （2）輸電線容性功率損耗隨覆冰厚度增加而增加，在相同覆冰厚度下不同覆冰形狀的容性無功損耗規(guī)律為：圓形橢圓新月形，橢圓≈偏心橢圓翼型。具有覆冰越不規(guī)則，則容性無功損耗越高的特點(diǎn)。 （3）對于單端接地電纜，電纜隧道積水導(dǎo)致容性無功增加率達(dá)到49.89%。在偏心位移為1~2.5mm的區(qū)間，電纜容性無功增量隨偏心位移增加呈二次函數(shù)關(guān)系遞增。 根據(jù)輸電線下方不同環(huán)境溫濕度下的定點(diǎn)測量電場值，擬合分析了空氣相對介電系數(shù)與環(huán)境溫濕度的關(guān)系。基于坡印亭矢量的輸電線能量傳輸表征模型計算了環(huán)境溫濕度對輸電線能量損耗的影響，并從能量的角度反推了不同環(huán)境溫濕度下輸電線等效電路參數(shù)。
[Abstract]:With the increasing of power load in China, the construction of high voltage underground power cable and UHV transmission line has been advancing rapidly in the past few years. Because of its long transmission distance and large transmission capacity, the reactive power compensation of high voltage transmission line is of great significance to the stable operation of the transmission line. When overhead transmission lines are covered with ice and the environment of underground power cable tunnels is damaged, the equivalent electrical parameters of transmission lines will change, and the change of electrical parameters of transmission lines should be considered in the calculation and analysis of reactive power of transmission lines. For the normal operation of transmission lines, the transmission power of transmission lines is often calculated by the method of "path". When the transmission line is covered with ice and the environment of underground power cable tunnel is destroyed, the complexity of calculating transmission power from the angle of "path" will be increased because of the change of equivalent electrical parameters of transmission line. Therefore, this paper presents a representation model of transmission line energy transmission based on Poynting vector, that is, calculating the transmission power of transmission line from the angle of "field". In this paper, the numerical expression of electromagnetic energy representation by Poynting vector is first derived, and then a three-dimensional energy transmission representation model for transmission lines is proposed based on the spatial step FDFD method. In the model, a band charge model is proposed to calculate the initial cross-section electric field intensity of transmission lines. The three-dimensional transmission energy representation model based on FDFD can calculate the power transmission of irregular ice-covered overhead transmission lines and non-standard laid cables. In this paper, the energy transmission characterization model of transmission line based on Poynting vector is used to calculate the power transmission of overhead transmission lines, such as sag and icing, dielectric stratification, eccentricity and water accumulation in cable trenches. The results show that: Sag can increase capacitive reactive power and inductive reactive power loss. In the section at the lowest point of sag, the capacitive reactive power loss per unit length increases greatly, the inductive reactive power loss decreases slightly, and the unit length capacitive and inductive reactive power loss increases slightly at the traverse suspension point. (2) the capacitive power loss of transmission lines increases with the increase of icing thickness. The law of capacitive reactive power loss for different icing shapes under the same ice thickness is as follows: circular elliptic crescent, ellipse 鈮

本文編號：1819219