Abstract
Transient protection has the advantage of ultra-high-speed action, but traditional transient protection is susceptible to the influence of two fault condition attributes, namely, transition resistance and initial angle of fault, and there are the problems of insufficient sensitivity and insufficient reliability under weak faults. To this end, the propagation characteristics of high-frequency components of transient voltage in bus and line systems are explored, and a new method of unit protection based on the entropy difference in transient voltage information is proposed. In order to solve the problem of single-ended transient protection not being able to reliably distinguish line faults from bus faults and adjacent line first-end faults, the difference between the entropy of line voltage and the entropy of bus voltage was introduced as a fault characteristic. Aimed at the susceptibility of transient protection to the influence of fault condition attributes, composite fault characteristics containing fault attribute information were obtained by integrating fault characteristics with fault condition attributes to overcome the adverse influence of fault condition attributes on transient protection and improve the reliability of the protection. The algorithm solved 38.9% of the original cross-data, 36.1% of the false actions, and 6.1% of the rejected actions. Finally, the accuracy and reliability of the proposed algorithm were verified by extensive ATP-Draw simulation tests.