Dynamoelectric machine
AssigneeThe Garrett Corporation
InventorKeith M. Chirgwin
Life of this patent
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Abstract
A dynamolectric machine stator has a primary winding for single phase alternating current input and a secondary winding for polyphase alternating current to be supplied from output terminals. The secondary winding is connected such that at least two frequencies are provided at the terminals. The rotor has two windings thereon for excitation, one being excitable for one frequency output and the other rotor winding being excitable for another frequency output at the secondary terminals. Another secondary winding may be provided on the stator to obtain a desired output terminal voltage at one of the selected frequencies.
Claims7
A drive system for an electric vehicle comprising:
- means for supplying high voltage, alternating current to said vehicle from a stationary source;
- a dynamoelectric machine on said vehicle including a primary stator winding defining a plurality of primary stator poles connected to receive said high voltage, alternating current, and including a multiphase secondary winding;
- a rotor on said machine including exciting winding means defining each of a first plurality of rotor poles and a second plurality of rotor poles greater in number than said first plurality of rotor poles;
- a multiphase vehicle drive motor responsive to multiphase alternating current input power for driving the vehicle at speeds directly related to the magnitude and the frequencey of said electrical input power;
- means for supplying exciting current to said exciting winding means to selectively excite said first and second plurality of rotor poles, said rotor being operated in response to the excitation of said plurality of rotor poles at a synchronous speed related to the frequency of said high voltage alternating current and to the number of said plurality of primary stator poles, said multiphase secondary winding being magnetically coupled to said exciting winding means and supplying said drive motor with multiphase alternating current input power at a first frequency in response to the excitation of said first plurality of rotor poles to thereby accelerate said drive motor toward a first speed, said multiphase secondary winding supplying said drive motor with multiphase alternating current input power at a second frequency higher than said first frequency in response to the excitation of said second plurality of rotor poles to thereby accelerate said drive motor toward a second speed higher than said first speed.
A method for accelerating an electrically driven vehicle comprising the steps of:
- supplying high voltage, alternating current from a stationary source to a stator winding of a dynamoelectric machine;
- supplying exciting current to a multi-pole first rotor winding of the machine to operate the machine at a synchronous speed and to produce multiphase alternating current input power at a first frequency from a multiphase secondary stator winding in magnetic coupling relation to the first rotor winding of the machine;
- supplying the multiphase alternating input power at the first frequency to a drive motor of the vehicle to accelerate the vehicle toward a first speed related to the first frequency;
- supplying exciting current to a multi-pole second rotor winding of the machine having a greater number of poles than the first rotor winding while continuing to operate the machine at the synchronous speed to produce multiphase alternating current input power at a second frequency higher than the first frequency from a multiphase secondary stator winding in magnetic coupling relation to the second rotor winding;
- and,
- supplying the multiphase alternating current input power at the second frequency to the drive motor of the vehicle to accelerate the vehicle toward a second speed higher than the first speed and related to the second frequency.
Dependencies are inferred from the claim text.