a condition that occurs in an electric power system when the total real or reactive power of the power plants in the system is insufficient to supply all consumers with electric power of the required quality.
A shortage of real power can result in a lowering of frequency throughout the power system and can ultimately lead to a breakdown condition. The breakdown condition can be prevented by connecting additional (spare) generators to the system or by disconnecting some of the consumers. A shortage of reactive power causes a voltage drop in the system. In extreme cases a so-called voltage avalanche can develop, resulting in emergency disconnection of all consumers. A voltage avalanche is best prevented by boosting or regulation of the excitation of the generators and synchronous compensators connected to the system, as well as by proper selection of the compensating equipment used in the system.
REFERENCESKniazevskii, B. A., and B. Iu. Lipkin.Elektrosnabzhenia promyshlennykh predpriiatii. Moscow, 1969.
Markovich, I. M.Rezhimy energeticheskikh sistem, 4th ed. Moscow, 1969.
B. A. KNIAZEVSKII