电晕笼是用来模拟输电线路导线电晕特性的一种经济、有效的方法。为了深入研究海拔0~3800m范围内交流输电线路电晕起始电压的海拔修正系数,利用可移动式小型电晕笼在武汉、西宁、格尔木、纳赤台进行了多种4分裂导线的电晕特性试验。导线电晕放电后产生了光子,紫外成像仪可以记录光子的数量,从而利用"切线法"求取导线的电晕起始电压。通过武汉、西宁、格尔木和纳赤台4个不同海拔点的导线在干燥条件下的电晕起始电压测量结果,发现它们不适合用GB/T2317.2-2000或GB/T775.2-2003来进行海拔校正,因而提出了工程用指数和线性海拔校正方法,误差〈5%,可以满足工程实际需要。
In order to obtain the altitude correction factor of corona inception voltage of AC transmission lines in the area of 0 to 3800 meters,a mobile corona test cage was applied to research the influence of altitude changes on AC corona characteristics of several four-bundle conductors in Wuhan,Xining,Geermu,Nachitai,respectively.Photons released as a result of corona discharge on the conductors were detected by the ultraviolet detection apparatus.According to the apparent change of photon number,corona inception voltage could be acquired by the tangent method.With the obtained corona inception voltage,it was found that the existing GB/T 2317.2-2000 or GB/T 775.2-2003 was not appropriate for getting altitude correction factors.Finally,the exponential and linear correction formulas were introduced,which well fitted with the experimental values with a maximum error of 5%.