Quality Assessment Method for Insulator Sample Bank Based on Sampling Theory

Insulator strings are important components in power systems to support and isolate transmission lines. Due to long-term exposure to the natural environment, insulator strings are susceptible to damage, such as self-explosion, broken umbrella skirts, and galvanic corrosion, which is one of the most common failures. Once damaged, it can lead to widespread power outage, which affects people’s life and industrial production, so it is necessary to inspect and replace the damaged insulator strings regularly. This thesis proposes a quadratic sampling based approach to assess the quality of insulator string sample banks. Through simple random sampling, estimation and interval estimation of the sample pool, the pass rate and average number of labels of the original sample pool are initially assessed and compared with the usage requirements to decide whether to carry out a second sampling or not; the second sampling used SADS as an evaluation metric to assess the performance of the insulator string sample bank.