Single Phase Switching Tests on 765 kV and 750 kV Transmission Lines

Single phase switching compensation schemes for transposed and untransposed lines were tested during staged fault tests on the 243 km, 765 kV Kammer-Marysville line (USA) and the 417 km, 750 kV Vinnitsa-Dnieper line (USSR). Conventional four-legged reactors were used on both lines, and in addition a switched four-legged reactor bank was utilized on´the untransposed Kammer-Marysville line. During the tests, a large-range of single phase switching parameters was simulated, which intentionally varied the secondary arc current and the recovery voltage on the opened phase. The power frequency component of the secondary arc current was varied from 3 Arms to 80 A rms. The upper limit of the recovery voltage rate of rise reached about. 15 kV/ms. The tests definitely proved the applicability of high-speed single-phase reclosing on shunt-reactor-compensated EHV lines.