STUDIES OF EHV TRANSIMISSION LINES PROTECTION BASED ON POWER BALANCE

摘要

According to long line equation, this paper proposes a protection theory based on power balance. The theory deduced one terminal sampled data from another terminal sampled data. The in-zone faults or out-zone faults can be judged from the integrated powers, which are integrated with deduced sampled data and real sampled data during a time interval. The results simulated by EMTP shows that the theory has the following characteristics: operate quickly, relay can operate in 3/4 power frequency period; excellent performance under high resistance; not influencing by running mode.