Charge comparison protection of transmission lines-communications concepts

The authors present the basic concepts of a digital approach to the communications requirements of a new transmission line protection scheme. Charge comparison is a new transmission line protection system. It compares local and remote quantities of charge, using a bidirectional communications channel. Charge comparison is a form of current differential relaying. Traditional current differential relaying schemes have three critical communications-related problems: protection is lost if the channel fails, a large channel capacity is required, and precise channel delay compensation is required. In large measure, charge comparison overcomes these three communications-related problems.<
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