Fault locating and severity assessment for power distribution systems based on elasticity network topology mapping

Abstract

Although fault locating in power distribution systems has been widely studied, very few research works consider fault severity assessment, i.e., fault influence on other lines. The main reason behind this is the lack of a unified standard to quantify and assess the severity of different type of faults. In this paper, a novel power distribution system fault locating and severity assessment method is proposed based on elasticity network mapping. The principle of the proposed method is based on elastic coefficient, which reflects the state of the elastic spring by its numerical value. The partial derivative of distribution line power flow to its phase difference, denoted as distribution rate (DR), is analyzed to map the line fault occurrence to the numerical change in DR. Besides, the method normalizes the DR values of different distribution lines into standardized values between 0 and 1, so that normalized comparison can be achieved. Because DR value is inversely proportional to the severity the fault, by comparing the DR of each line, the fault location and severity can be accurately evaluated. Simulation tests are performed in 10 different test feeders with around 35% of nodes installed with measurement units, reporting a 99% accuracy.