Reclosing Over-Voltage Analysis for Single-Phase Reclosure in UHV Transmission Lines

Along with the increasing application of high-impedance, long-distance and large-capacity power transmission lines in ultra-high-voltage (UHV) alternate current(AC) system, the closing over-voltage in UHV is vital to determine the insulation level of the main power equipments, In this paper, using the UHV transmission project from Jincheng to Jinzhou via Nanyang in China as ATP simulation model, the single-phase reclosing over-voltage features under different fault conditions are further studied. The results show that present dead time single-phase reclsoure technology using in UHV transmission has higher risk of over-voltage. In order to decrease the reclosing over-voltage level, using intelligent single-phase reclosure with adaptive reclosing time that determined by the fault nature is helpful to avoid reclosing over-voltage level. Simulations show that the proposed reclosure scheme is favorable to reduce the reclosing over-voltage in UHV transmission lines.