Wide area fault location on transmission systems using synchronized/unsynchronized voltage/current measurements

Abstract

Wide area impedance-based fault location methods use global positioning system (GPS) for pinpointing the fault position. GPS signal loss occurs repeatedly in power system because of slow communication link or lack of synchronized sampling infrastructure that makes synchronized measurements unavailable in some parts of the grid. To overcome the grid synchronization problem this paper presents a fault location method that integrates synchronized and unsynchronized current and voltage measurements in a system of equation form. In this system the magnitude of measurements is considered for all measurements and the phase angle is considered only for synchronized measurements. On the other hand, any type of measurements (current and voltage) which is done synchronized or unsynchronized can be integrated in the developed system. The integration of GPS synchronized and unsynchronized measurements prevents the GPS signal loss to affect the fault location problem, while many of the previous methods are not applicable under these conditions. Then the formed system is solved with the aim of finding the location of fault utilizing an iterative approach. The line distributed parameter model is used in this paper, which provides more accurate results nearer to real values. The proposed method is validated by WSCC 9-bus and IEEE 39-bus test systems which reveal accurate estimation even in conditions that the GPS signal is not accessible.