Differential protection method for EHV transmission line based on current traveling wave prediction

Abstract

At present, the EHV transmission system in China has entered a new stage of large-scale construction, which is different from the general EHV transmission lines. The distributed current in the EHV transmission lines has increased substantially. To realize the overall balance of long-distance transmission in the power grid, a differential protection method for EHV transmission lines based on current traveling wave prediction is proposed. The fault current traveling wave of the EHV transmission line is predicted. The fault current traveling wave section is distinguished, and different schemes are selected to realize the traveling wave differential protection for internal and external faults. The simulation results show that the proposed method is reliable and sensitive for the protection of UHV transmission lines, and has certain practical value for ensuring the stable operation of the smart grid.