METHOD OF LOCATING A FAULT IN A PREDETERMINED MONITORING REGION OF A MILTIPHASE ELECTRICAL POWER TRANSMISSION SYSTEM

摘要

The invention concerns a method of locating a fault (F) on an electrical transmission line (E). Precursor fault-indicator measurement values (I) of both aerial modes ( alpha , beta ) are formed from sample values of currents and voltages stored immediately before and during the fault using the Clarke transformation. These indicator measured values (I) are used to determine the phase angle ( delta ) for synchronisation, thus ensuring that fault-indicator voltage values (II) of both aerial modes ( alpha , beta ) can be produced without error by asynchronous formation of the sample values. The fault-indicator voltage values (II) of one aerial mode ( alpha , beta ) are subtracted from those of the other and the differences (III) thus formed are squared. By estimating the minimum value of the sum of the squared difference (III), the location of the fault (F) is determined.