Carrier-Current Transfer-Trip-Relaying Field Tests and Operation Experience

Field tests and operating experience with direct underreaching carrier Power Administration are discussed. The carrier equipment used operates in the 40-to-200-kv band and is of the narrow-band crystal-controlled frequency-shift type. The relaying scheme as developed has performed with a high degree of reliability, with over 99% successful operation. Field tests, operating performance, and areas of improvement are discussed.