Relay-Type Boosting

Relay-Type Boosting


an intensification process of increasing the excitation of synchronous generators, phase modifiers, and electric motors; the process is carried out and monitored by automatic equipment. In this process, the exciting current of the electrical machines and, as a result, the electromotive force in the stator windings, are increased at the maximum possible rate to the highest level permitted by the specifications.

Relay-type boosting is needed when the voltage drops abruptly, usually because of a short circuit in the electric power system. During a short circuit (under emergency conditions) and after the faulted section has been disconnected (under post-emergency conditions), relay-type boosting raises the voltage and improves the dynamic stability of the power system, thereby providing a rapid restoration of normal operating conditions. On the other hand, in a number of cases relay-type deexcitation (reduction of excitation) of generators is used to prevent dangerous overvoltages—for example, when there occurs an emergency disconnection of load. Relay-type boosting devices are used in systems for the automatic regulation of excitation.


Venikov, V. A. Perekhodnye elektromekhanicheskie protsessy ν elektricheskikh sistemakh, 2nd ed. Moscow, 1970.
Barzam, A. B. Sistemnaia avtomatika, 3rd ed. Moscow, 1973.