Calculation method of the bell insulator to double-shed insulator contamination ratio based on the evaluation accuracy of area pollution level

In order to make full use of the ESDD test data of on-site bell insulators to evaluate the area pollution level, a new calculation method of the bell insulator to double-shed insulator contamination ratio is proposed, which is based on the principle of minimizing the misjudgment of the area pollution level. Natural contamination test was carried out in Taizhou, Zhejiang province, and the contamination ratio was calculated based on the test data. According to the probability distribution model of test data, 10,000 sample data are randomly generated for verification. The results show that the misjudgment rate of pollution area of the proposed method is 21.41%, which is lower than the traditional method of taking the arithmetic average or geometric average for several test points.