Detection of high impedance fault in distribution system considering distributed generation

High impedance fault (HIF) is hard to detect owing to their relatively small magnitude compared to normal currents. When an overhead power line loses its support, fall on a poor conductive surface or substance, a high Impedance Fault results. As the fault current is very small during it becomes very difficult to be sensed by over current relay. So equipment and public safety become a matter of great concern. Due to its relatively small fault current nature it became an area of interest and need more detailed study to detect the HIF fast. Here, we try to present a new detection method which uses residual power as an input in the paper. The method is very simple and easy to implement compared to other heuristic methods. The proposed method is tested on eight bus system with DG connected at bus 4. The system is operating at 11kV voltage. The model is simulated in PS CAD. Capacitor switching, Generator switching, Unbalanced load condition, fault with and without DG are also simulated. Obtained results show that the method is able to detect High Impedance Fault with the inception of non-fault events also.