1000 kV罐式电容式电压互感器长期带电考核研究

Study on Long-term Live test of 1 000 kV Dead Tank Capacitor Voltage Transformer

罐式电容式电压互感器(以下简称罐式CVT)是一种采用SF6气体绝缘的新型特高压GIS工程用电压互感器,相比传统柱式CVT具有电容量不受杂散电容影响的优势。受限于容性设备自身特点,罐式CVT的误差容易受到温度、频率等因素的影响。为了更好地掌握1000 kV罐式CVT长期运行状态和运行中的误差情况,本文对误差影响因素进行了分析,建立了带电考核系统,包括温度监测系统、故障录波系统、误差校验系统,采用0.2级电容式电压互感器与罐式电容式电压互感器进行误差对比,实现了不同温度变化下误差的对比校验和长期带电考核。研究表明,1000 kV罐式CVT绝缘性能良好、温度误差合理,满足工程需求。文中研究成果为1000 kV罐式CVT进行工程应用奠定了基础。

Dead tank capacitor voltage transformer(hereinafter referred to as dead tank CVT)is a kind of new type voltage transformer insulated by SF_(6) gas for UHV GIS projects,which,compared with the traditional column CVT,has the advantage that the capacitance is free from the influence of stray capacitance.The error of the dead tank CVT is susceptible to such factors as temperature and frequency due to limitation of the characteristics of the capacitive device itself.For better understanding of the long-term operation condition and the error of the 1000 kV dead tank CVT in operation,the error influencing factor is analyzed in this paper and the live assessment system,including temperature monitoring system,fault recording system and error calibration system,is set up.The 0.2-level capacitor voltage transformer and the dead tank capacitor voltage transformer are used for error comparison so to achieve the comparison calibration and longterm live test at variation of different temperature.The study shows that the 1000 kV dead tank CVT has good insulation performance,reasonable temperature error and can meet the needs of projects.The study results in this paper lay a foundation for the engineering application of the 1000 kV dead tank CVT.