(also, close regulation), automatic regulation of excitation or rotational speed in synchronous generators or compensators according to deviations in voltage or frequency or according to the first and second derivatives of the rotor and stator current, voltage, or other operating parameters of a power system. Close regulation makes it possible to predict and prevent incipient changes in operating conditions.
Close regulation is achieved by using automatic power regulators. Such regulators feature rapid and high response to an excitation current or to the admission of an energy carrier, such as steam or water, into a turbine or hydraulic generator whenever a change in operating conditions occurs. Examples of such changes include an increase or decrease in the power being transmitted or short circuits. The purpose of close regulation is to maintain the required voltage at some given point in the adjoining section of a power grid and to prevent a breakdown in the parallel operation of power plants connected to the power system. Such breakdowns may involve static, dynamic, or overall stability.
Automatic close regulators of excitation are manufactured according to a standardized design. Such regulators are installed in a number of generators at hydroelectric power plants, including those at Bratsk and Krasnoiarsk. They are also used in the high-power generators of thermal and nuclear power plants. The turbine generators of the Slaviansk and Kostroma state regional electric power plants are also equipped with automatic close regulators of rotational speed. When combined with fast-response thyristor exciters of synchronous machines, automatic close regulators substantially improve the quality of electric power supply and increase the operational reliability of the Integrated Electric Power Grid of the USSR.
N. I. OVCHARENKO