Controlled Switching of Series Compensated Transmission Lines: Challenges and Solutions

A new controlled switching method for purely series compensated transmission lines is proposed here. The main idea is based on the estimation of trapped charges using a recursive digital filter for correction of the secondary voltage of the capacitive voltage transformer. Several operating conditions of series capacitor banks are taken into account to define the controlled switching strategy for transmission line reclosing. It is also shown that one can take advantage of the existing techniques for uncompensated and shunt compensated lines. The challenges and potentialities of the proposed method are highlighted through alternative transient program (ATP) of a 500-kV power system where switching transient overvoltages are limited to 1.85 p.u.