Statistical Distribution Law of CVT Test Data in Guangzhou Power Grid

This paper analyzes the distribution law of dielectric loss and capacitance change rate of capacitor voltage transformer (CVT) in Guangzhou power grid since 2010, and analyzes the 90% and 95% quantile values. The results show that the dielectric loss and capacitance change rate conform to the approximate lognormal distribution and approximate normal distribution respectively, and the 95% quantile values are 0.187% and 1.68% respectively. At the same time, the influence of operating years and voltage level is discussed, and the influence of operating years on the 95% quantile value of normal CVT is negligible. For the influence of voltage level, the 95% quantile value of 500 kV CVT is less than other voltage. The 95% quantile values of dielectric loss of 110 kV, 220 kV and 500 kV CVT are 0.191%, 0.186% and 0.14%, respectively, and the absolute values of capacitance change rate are 1.77%, 1.71% and 1.19%, respectively. Through the above data statistics, it provides operation and maintenance ideas for the safe operation of CVT.