Enhanced Protection Scheme for Smart Grids Using Power Line Communications Techniques—Part II: Location of High Impedance Fault Position

An effective protection scheme against high impedance faults (HIFs) has to efficiently confront the issues of detection and location simultaneously. In Part I of this study the issue of detection is investigated, while in Part II a method that deals with the exact location of HIF position using an installed power line communication (PLC) system is elaborated. This method comprises specific test signal injections into the power grid after a HIF alarm is set. Using impulse responses that are recorded by the PLC devices, the location of the fault may be derived. A flowchart that describes the usage of the complete method for HIF detection and location is presented. The impulse responses that correspond to several fault cases are shown and the methodology that may lead to the fault location is explained. The effect of the fault type and its impedance on the efficacy of the method is highlighted. Finally, the model is applied to a line that is part of the Greek rural distribution system and its validity is tested.