CURRENT TRAVELING WAVE PREDICTION-BASED METHOD FOR ELECTRIC POWER TRANSMISSION LINE DIFFERENTIAL PROTECTION

摘要

The present invention relates to the technical field of electric power system relay protection. Disclosed is a current traveling wave prediction-based method for electric power transmission line differential protection. The method: first, voltages and current traveling wave components of two ends of an electric power transmission line at sampling moments are collected; the voltages and current traveling wave components of the first 1/4 cycle moments of the sampling moments are utilized to predict the current traveling wave components of the two ends of the electric power transmission line at the sampling moments; respectively at the two ends of the electric power transmission line, a current traveling wave differential protection is constituted from the current traveling wave components of the sampling moments acquired via prediction and the current traveling wave components of the moments acquired via sampling by means of utilizing conventional proportional braking characteristics; if any one current traveling wave differential protection phase of the current traveling wave differential protection at the two ends of the electric power transmission line is activated, then protecting by transmitting a trip signal to circuit breakers at the two ends of the phase of the transmission line. The method of the present invention utilizes the voltages and current traveling wave components at the first 1/4 cycle moments of the sampling moments to predict and acquire the current traveling wave components of the electric power transmission line at the sampling moments, obviates the need for an interpolation operation to arrive at the current traveling wave components of the sampling moments, reduces the amount of traveling wave protection computation, is capable of completing a traveling wave fault protection function within a short data window of 1/4 cycle, is rapid in activating the protection, and is applicable in the traveling wave protection during the entire process of a transient fault of electric power transmission lines of various voltage levels.