Abstract:

This paper proposes a generalized admittance based method for fault location analysis of distribution systems. Based on the measurements collected from the feeder breakers and intelligent switches during a fault, the fault type and faulted feeder section are first determined by examining the over-voltages and over-currents on the breakers/switches. The load demands, faulted line segment and fault location are then determined sequentially by finding a set of loads, a line segment and a fault location that has minimal distance between the currents measured at the boundaries of the feeder section, and the estimated currents determined by multiplying the measured voltages by an equivalent admittance matrix determined for the feeder section when applying the given load and fault conditions to the feeder section. The proposed approach determines the equivalent admittance matrix for a feeder section with one or two measuring ports through topology and circuit analysis, and for a feeder section with more than two measuring ports through Kron reduction on nodal admittance matrix. Numerical examples are given to demonstrate the effectiveness of the proposed approach.