Earth fault localization with the help of the fast-pulse-detection-method using the new high-power-current-injection (HPCI)

With today´s increased demands on grid operation management new methods for earth fault localization and detection are required. The earth fault localization should be performed as quick as possible and under the condition, that the fault current at the fault location will not be significantly increased. The pulse detection method is widespread because only a current measurement is needed and the implementation is simple. With the installation of more than one relays along a line an in-depth localization of the earth fault is possible. Boundary conditions, which will be described in detail in the paper, will not always lead to an increased resolution into depth with an increased number of relays. In this paper a new and fast method based on a thyristor-controlled high-power-current-injection (HPCI) will be presented. Compared with traditional pulse detection, this method has a lot of advantages, which will be described in the paper.