Equivalent circuit model for the error analysis of field dielectric loss angle measurement

摘要

Dielectric loss angle is a very important parameter to evaluate the insulation condition of capacitive devices, which is the complement angle of voltage and leakage current. The angle value is hard to accurately obtained because of field interferences and other causes. The leakage current is so small which the signal path parameters and other interference contribute a fairly large error. In this paper, an equivalent circuit model of capacitive equipment considering multicomponent parameters is established. By analyzing the influence of electromagnetic field distribution and wiring modes on the leakage current path, an equivalent circuit model considering many influencing factors is proposed. This paper also analyzes the influence of aging, temperature and humidity on the equivalent circuit parameters, explores the causes of the current measurement error, and finally obtains the transfer function of the leakage current and the path component parameters.