Transient characteristics of single-phase to earth leakage

WANG Qing-liang

Abstract：The transient model was set up for single-phase to earth leakage by Karrenbauer transform matrix. Then,the relation between leakage characteristics and fault conditions were analyzed using the leakage equivalent circuit. It was concluded that the frequency distribution, attenuation properties of fault signals were determined by leakage resistance. The fault current component was influenced by leakage occurrence time. The transient process of zero-model voltage is obvious when high-impedance to earth leakage occurs, while no transient process of zero-model voltage appears in case of small-impedance to earth leakage. The attenuation speed, frequency component and value of transient current are discrepant between fault line and healthy line. The frequency band energy factor and the impedance factor were given to describe the fault transient signals. The theory analysis and simulation prove that the feasibility of the obtained conclusions. These transient characteristics can provide the theoretical foundation for studying the fast leakage protection. It can effectively shorten electric shock time and improve the security and reliability in collieries power supply.