电晕笼设计与应用相关问题的探讨

国内特高压电网建设已正式启动,特高压输电线路的电晕问题亟待研究,电晕笼是研究特高压交直流输电线路导线电晕的一种经济有效的手段,为此介绍了电晕笼的原理、结构、国内外已建电晕笼的参数及依托电晕笼开展的超特高压电晕特性的研究,并结合现有实验室用电晕笼装置,从电场分布、离子电荷运动、无线电干扰电流校正等方面探讨了电晕笼的结构、长度、边长(直径)等参数的设计原则,给出了电晕笼中交直流电晕电流、无线电干扰、可听噪声、电晕损耗、直流离子电流密度等效应的测量方法。最后基于世界各国电晕笼特点的总结,就国内试验基地大电晕笼的电压等级、结构和参数的合理选择提出了若干建议。

Discussion on the Design and Application of Corona Cage

Ultra high voltage(UHV) transmission project in China has been started.The electromagnetic environment directly related to corona phenomena becomes one of the important factors in the design and operation of UHV transmission lines.So radio interference(RI),audible noise(AN),corona loss (CL) and ion current,which are caused by AC and DC conductor corona,must be comprehensively considered in the design of UHV transmission lines.Corona cage is an effective and economical means for duplicating the corona phenomena of the UHV transmission lines by applying lower voltage on the conductor in the cage,which can be used to study the influence of different factors on corona characteristics by varying the test condition and conductor configuration.The aim of this paper is to give an introduction to the design and application of corona cage.The mechanism and structure of corona cage are presented.Many high voltage laboratories in foreign countries investigated the UHV and EHV corona effects in corona cages as early as 1960's to obtain useful data and empirical formulas.The dimension of these cages and the experiments in these cages are summarized to provide a basic understanding on the status of corona study.From the point of view of electrical field,ion flow and RI correction,how to specify the mechanical parameters of the cage is discussed.Based on the principles mentioned in this paper,a small corona cage is already constructed for the research on corona effects in our laboratory.The measurement methods of corona current,radio interference,audible noise,corona loss and ion current are also discussed.Some suggestions about voltage level,structure and dimension are given for the construction of outdoor big corona cage in China.