低温环境下电子式电流互感器异常原因分析

Analysis of abnormal causes of electronic current transformer in low temperature environment

电子式电流互感器作为直流系统重要的测量设备,是保证直流系统安全稳定运行的基础。针对某±800 kV特高压换流站两起电子式电流互感器异常,通过比对激光器驱动电流、数据电平、环境温度等状态量,详细分析设备异常根本原因,并开展激光器供能光路损耗静态试验和远端模块高低温循环试验,从侧面验证分析结果的正确性。同时,在现场检查过程中还发现了电子式电流互感器在低温环境下光缆埋管深度不足、穿管排水不畅、远端模块性能劣化等问题,进而提出增加埋管深度、优化埋管敷设方式、增加备用远端模块及定期开展光纤衰耗测试等针对性建议,为换流站基建验收及运行维护提供参考和借鉴。

Electronic current transformer,as an important measuring device in DC system,is the basis to ensure the safe and stable operation of DC system.Aiming at two abnormal electronic current transformers in a ±800 kV UHV converter station,the root causes of equipment abnormality are analyzed in detail by comparing the state variables such as laser drive current,data level and ambient temperature.The static test of laser energy supply optical path loss and the high and low temperature cycle test of remote module are carried out to verify the correctness of the analysis results.At the same time,in the process of on-site inspection,it is also found that there are some problems existing in electronic current transformer in low temperature environment,such as insufficient buried depth of optical cable pipe,poor drainage through pipe,and deterioration of performance of remote module.Suggestions such as increasing buried pipe depth,optimizing buried pipe laying mode,adding spare remote modules,and regularly carrying out optical fiber attenuation tests are put forward,which provide a certain reference for the subsequent acceptance and operation maintenance of converter station.