A Time-Domain Cross-Differential Protection Algorithm For Double Circuit Transmission Lines
Double Circuit Transmission Line, Cross-Dierential Protection, Time Domain Protection, Incremental Replica Currents.
This thesis project proposes a new cross-dierential time domain-based protection algorithm for double circuit transmission lines. Incremental replica currents are used for each phases of both circuits of the evaluated double circuit line. Considering the algorithm is based on the concept of cross dierential protection, it is capable of automatically identifying the defective phase, thus allowing phase segregated trip. To evaluate and validate its performance and proper operation, the Alternative Transients Program (ATP) software was used to simulate a 500 kV transmission line 200 km long when subjected to dierent operating conditions. The simulated cases were then experimentally assessed by using real commercially available relays. In this manner, the performance of the proposed algorithm could be compared with native functions from the evaluated relays. The employment of the proposed algorithm results in secure, wide-ranging, and fast operations. Thus, adoption of the proposed cross-dierential time domain function alongside readily available device-embedded protection functions represents a promising and appropriate alternative for the protection of double circuit transmission lines.