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AssigneeWestinghouse Electric Corp.
InventorsLeonard W. Finnell, Sigrud R. Petersen, Dale I. Gorden
Estimating the term…
An excitation system for a synchronous generator includes a conventional brushless exciter for providing base excitation for rated power output and a controlled source of direct current interconnected with the conventional brushless excitation system to supplement the base excitation. The supplementary excitation is supplied to the rotating field winding of the synchronous generator to provide forcing excitation to permit operation of the generator at power levels which exceed the generator's base power output level. In a preferred embodiment of the present invention, means operable to derive a control signal proportional to a predetermined function of the field winding excitation and of the power output of the generator is provided to control the magnitude and polarity of the supplemental excitation to permit operation of the synchronous generator at power levels which exceed its base power output level, to provide negative direct current excitation to permit fast-de-excitation of the generator, and to provide substantially zero supplemental excitation when the generator is operating at its base power output level.
In a synchronous generator of the type having a rotating field winding turned by a prime mover, and wherein direct current excitation for said field winding is derived from said prime mover by an exciter system including a pilot exciter having a permanent magnet rotor turned by said prime mover to permit operation of said generator at a first power output level which corresponds to a base mode of operation, the combination with said exciter system of a controlled source of direct current interconnected with said excitation system to supplement the excitation supplied to said rotating field winding to permit operation of said generator at a second power level which corresponds with a forcing mode of operation, and means operable to derive a control signal proportional to a predetermined function of the excitation applied to said field winding and of the power output of said generator, said controlled source being connected to receive said control signal and being operable to control said supplemental excitation in response to a predetermined function of said control signal.
In a synchronous generator having a rotor member turned by a prime mover, a field winding disposed on said rotor member, a main exciter having a stator member carrying a field winding and a rotor member carrying an armature winding, a rotatable rectifier assembly having an input circuit connected to receive alternating current power from said main exciter armature and an output circuit connected to conduct direct current excitation through said synchronous machine rotor field winding, means operable to convert the rotational energy of said prime mover to direct current excitation, said converting means having an output circuit connected to provide direct current base excitation to said field winding, the combination with said converting means of means operable to derive direct current excitation from a supplemental source of electrical power, said deriving means having an output circuit connected to supply direct current forcing excitation to said field winding to supplement the excitation provided by said converting means, means operable to derive a first control signal proportional to a predetermined function of the main exciter field excitation and of the power output of said synchronous generator, said excitation deriving means being connected to receive said control signal and being operable to control said forcing excitation in response to a predetermined function of said control signal.
In combination,
Dependencies are inferred from the claim text.