Fault Location Using Voltage Measurements

This paper presents a novel method for locating short-circuit faults in electric power systems. The origins of the method are in the concept of vulnerability contours, which is used in assessing the likelihood of voltage sags effecting a given network area. The method is applied in an off-line step and an on-line step. The on-line step consists of measuring voltage sags at selected system buses. The off-line step consists of estimating the most likely fault location by matching measured voltage sags with the ones calculated through the fault simulations. In the process, the fault resistance is estimated as well. To cope with the inherent uncertainty in the problem, fuzzy logic reasoning is applied. The performance of the method is demonstrated using some typical examples. Since the actual measurements of voltage sags were unavailable, fault simulations were conducted to emulate a real measuring process.