Analysis Method for Transient Single-Phase Fault Removal on EHV Transposed Transmission Lines

In this paper some aspects of single-phase auto-reclosing on EHV transposed lines equipped four-legged shunt reactors are discussed. It is shown that the proper representation of the actual line transposition should be adopted to determine the recovery voltage and secondary arc current. When balanced transmission line model is used the real mutual capacitances and inductances are replaced by average values, which will result in lower secondary arc current values than those that will actually occur. This common practice should be avoided. Additionally a mitigation procedure based on four-legged shunt reactors and switched capacitor banks is presented.