倒置式油浸电流互感器内部温度场分布及内部压力影响特性研究

Internal temperature field distribution and influencing characteristics ofinternal pressure of inverted oil-immersed current transformer

电流互感器在电力系统中将一次系统中的大电流转换为供二次测量计量保护用的小电流,对电力系统的稳定运行及故障电流测量具有不可或缺的作用。在线运行过程中,由于局部放电、发热故障等原因造成了互感器内部油中气体异常增长,导致内部压力急剧增大,易造成绝缘损坏进而发生爆炸等事故。为研究互感器内部温度场分布及压力变化影响因素,及时发现内部压力剧增故障,通过ANSYS软件仿真建立了220 kV倒置式油浸电流互感器模型,利用有限元分析方法得到了倒置式油浸电流互感器内部温度场分布规律,并通过建立倒置式油浸电流互感器试验平台,验证了仿真的有效性,同时设计了基于MD-TPR互感器的压力在线监测系统,得到了互感器内部压力影响特性。

The current transformer converts the large current in the primary system into a small current for secondary measurement and measurement protection in the power system.It plays an indispensable role in the stable operation and fault current measurement of the power system.However,during the online operation process,the abnormal increase in gas of the oil inside the transformer induced by partial discharge,heat failure,etc.will lead to sharp increase of the internal pressure,which will easily cause insulation damage and explosion.In order to study the internal temperature field distribution of the transformer and the influential factors of pressure changes so as to detect the internal pressure surge failure in time,a model of 220 kV inverted oil-immersed current transformer was established by ANSYS software simulation.Based on the model,the distribution law of internal temperature field of the current transformer was obtained by finite element analysis method.An experimental platform was established to verify the validity of the simulation.At the same time,an online pressure monitoring system based on MD-TPR transformer was designed,and the internal pressure influence characteristics of the transformer were obtained.