套管介损在线监测测量误差及其影响因素试验研究

Experimental Research on Measurement Errors and Its Influencing Factors for On-Line Tan Delta Monitoring of High-Voltage Bushings

结合工程实际,分析了介质损耗角正切值tanδ在线监测的误差影响因素。建立了考虑多元件参量包括套管、电流传感器、信号通道以及信号调理单元的复杂等值电路模型,通过试验得到了电路模型中主要的等效电气参数。搭建了高、低压试验平台以模拟套管介损测量,模拟在复杂电磁及大气环境下传感器接线方式、空间电磁场对测量回路以及tanδ测量结果的影响,结合电路仿真分析了温、湿度对电流传感器测量角差的影响规律,通过老化试验,研究了元器件老化对信号调理单元等值电气参数和输出相差的影响。理论分析和实验结果验证了多因素对测量二次系统的影响是导致测量结果波动的主要原因。

In this paper,combined with engineering practice,the factors affecting the error of online monitoring of the dielectric loss tangent value tanδare analyzed.A complex equivalent circuit model considering multi-component parameters including bushings,current sensors,signal channels and signal conditioning units is established,and the main equivalent electrical parameters in the circuit model are obtained through experiments.A high and low voltage test platform was built to simulate the casing dielectric loss measurement,simulate the sensor wiring method under complex electromagnetic and atmospheric environments,the influence of the space electromagnetic field on the measurement loop and the tanδmeasurement results,and combined with circuit simulation,the influence of temperature and humidity on the angle difference measured by the current sensor is analyzed.Through the aging test,the influence of component aging on the equivalent electrical parameters and output phase difference of the signal conditioning unit is studied.Theoretical analysis and experimental results verify that the influence of multiple factors on the measurement secondary system is the main reason for the fluctuation of the measurement results.