An Innovative Method for Voltage Detection in Overhead Line Systems

The condition monitoring of overhead lines is a central task of network operators. The monitoring of overhead line currents, e.g., with overhead line indicators, is already state of the art. Due to the increase in the number of decentralized generators, the power flow is not more uni-directional. As a consequence, the direction of fault currents can no longer be determined in a simple manner, as knowledge of the overhead line voltage is required to determine the power flow direction. This paper presents a sensor concept with a calculation method to detect the high voltage of an overhead line using sensors which are galvanically isolated from the ground potential. The new method has been successfully verified with measurements on a simulated overhead line in HV labs.