Fault Distance Calculation in Radial Distribution System Using Second Order Polynomial Analysis of Voltage Sag Profile

This paper proposes a nonlinear analysis of voltage sag magnitude and angle for fault distance calculation in distribution system. The method first identifies the fault section. Then, a rank approach is followed to identify and prioritize the faulty section. Later, the fault distance is calculated by creating a second order polynomial passing through the fault node. The testing is carried out in an actual distribution system of an electrical utility in Malaysia with 37 nodes. The test results show that the proposed fault distance gives very small percentage error.