固定式变压器在线监测系统

Fixed on line monitoring system for power transformers

研制了一套新型固定式变压器局部放电在线监测系统，采用声—电联合监测方法连续监测四台大型变压器的局部放电，具有事故追忆、故障报警和定位等功能。各种抗干扰措施的采用，有效地抑制了现场的电磁干扰，提高了监测灵敏度。利用光缆传输系统实现变电站主控制室的上位机与现场的测量系统之间的通讯以提高系统整体抗干扰能力和信号传输的可靠性。套管末屏注入法用于视在放电量的在线标定。目前该系统已在吉林一座５００ｋＶ变电所试运行一年多，工作良好。

A set of fixed on line partical discharge monitoring system for transformers is developed in this paper. More than four power transformers can be monitored continuously at the same time, then fault warning and localization are made by monitoring software. Various methods are used to reject interference and enhance the monitoring sensitivity of partial discharge. Optical cable is applied to communicate between measurement system near transformers and upper computer in main controlling room in order to improve reliability of monitoring system itself. On line calibration method, the pulse injection method through capacitive tapping of bushing, is applied for measurement of apparent discharge. This system has been in operation steadily in one 500 kV substation in Jilin Province for more than one year.