. American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines . relays should fail, the speed-limitingdevice and the overload coil are both available to open the circuit shut down of the converter from any cause is indicated by the under-load relay. For normal stoppage of the synchronous converter, the run-ning switch of the alterating current supply is opened, which leaves theconverter running as a direct current motor. The reverse-current relays SPECIAL
. American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines . relays should fail, the speed-limitingdevice and the overload coil are both available to open the circuit shut down of the converter from any cause is indicated by the under-load relay. For normal stoppage of the synchronous converter, the run-ning switch of the alterating current supply is opened, which leaves theconverter running as a direct current motor. The reverse-current relays SPECIAL PLANT AND LINE PROBLEMS 329 are set so that they will operate on the current which the converter takes asa direct current motor and their operation opens the main circuit breakersand disconnects the converter from the direct current busbars. As theconverter slows down, the governor assumes its starting position and thefield contactors open so that everything is ready for a new start. Inaddition to the governors for closing the field circuit, the converter isequipped with the usual centrifugal speed-limit for Transformer Groups in Parallel.—The reverse-power relay. Fig. 184.—Scheme of Connections for Transformer Group [is also suitable for transformer protection where transformer groups areoperated in parallel. It is for service where it is desired to open the alter-iuating current circuits when the direction of energy flow or power is re-j versed. A circuit breaker with shunt trip coils is required, the relay makingI connections to the trip coil to open the breaker, the specific purpose being: to cut out instantly the faulty group of transformers without otherwise. disturbing the system. This relay will operate equally well on delta-delta,[delta-star, star-delta or star-star, transformer connections. 330- HYDROELECTRIC PRACTICE Main SwitchA Main Trans. Main Switch Series Trans. TripOoil Series Trans. TripOoil Main Switch V\/W\A Protected Feeder Series Tran
Size: 1447px × 1726px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorkmcgrawhillb
