VFTO抑制新方法研究——高频过电压抑制导线

New Method of Restraining VFTO-the High Frequency Overvoltage Restraining Busbar

VFTO具有波前陡、幅值高、频带宽、持续时间长等特点,是GIS变电站及邻近电力设备安全的巨大威胁,必须采取措施对其进行抑制。现有的几种抑制方法均有一定的效果,也存在相应的缺陷。据此提出一种高频过电压抑制导线的设计。抑制导线由GIS母线改造的镂空螺线管及与之并联的电阻组成,安装方式与常规母线无异。在工频下,其正常进行电流、电压波的传输;当有高频过电压时,起抑制VFTO的作用。文中对高频过电压抑制导线抑制VFTO的机理进行了分析,说明了其抑制VFTO的优势。然后从抑制导线的结构分析其抑制VFTO的效果,抑制导线主要组成部件包括4个部分:抑制导线本体、环氧玻璃支撑件、无感阻尼电阻、梅花触头等电连接部件。最后对抑制导线的设计难点进行分析,并提出相应的措施。验证了高频过电压抑制导线确实可以抑制VFTO的幅值和频率。

VFTO has the characteristics of steep wave front, high amplitude, wide frequency band, long duration, etc. It poses a great threat to the security of GIS substations and neighboring power equipment, it must take measures to suppress it. The existing several inhibition methods have certain effects and corresponding defects. According to it, this paper presents a design of high frequency overvohage restraining busbar. It consists of a hollowed-out solenoid and a resistor connected in parallel with it, the installation method is the same as the conventional bus bar. At the power frequency, it normally conducts the transmission of current and voltage waves; when there is high-frequen- cy overvoltage, it acts to suppress VFTO. This paper analyzes the restraining VFTO mechanism by high frequency overvoltage restraining busbar. Then from the structure of restraining busbar to analyze the effect of restraining VFTO, restraining busbar consists of four parts： suppression of the wire body, epoxy glass support, non-inductive damping resistance, plum contact and other electrical connection components. Finally, the design difficulties of restraining wires are analyzed and corresponding measures are proposed. It is verified that the overvoltage restraining busbar does indeed suppress the amplitude and frequency of the VFTO.