Method for locating line-to-ground fault point of underground power cable system

摘要

The present invention provides method for locating a line-to-ground fault point of an underground power cable system wherein a distributed parameter circuit analysis theory is employed to consider a capacitive element of a cable in a underground power cable analysis, thereby providing an accurate estimation of the fault distance even when the arrangement of the cable and the fault resistance are varied. A method for locating a line-to-ground fault point of an underground power cable system of the present invention comprises steps of: modeling an equivalent circuit including an impedance element and an admittance element of a core and a sheath for each phase of an underground power cable; establishing a voltage and current equation for the core and the sheath of the cable by applying a distributed parameter circuit analysis method for each section about the fault point in the equivalent circuit; establishing an equation of a fault distance using a fault condition for an entire system and the voltage and current equation; and calculating the fault distance using the equation of the fault distance and a source side information and a load side information.