Fault-tolerant variable speed induction motor drive
AssigneeAlliedSignal Inc.
InventorsColin Huggett, Gabor Kalman
Life of this patent
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Abstract
A drive arrangement for a fault tolerant variable speed induction motor provides a pair of current (torque and flux) command signals. The current command signals are converted to a three-phase output with sinusoidally varying signals. The three-phase output is modified to enable the motor to operate in the event one of the motor phases is open or disconnected. The modified three-phase output is used to provide first, second and third gate logic signals which are used for driving the motor.
Claims15
A drive arrangement for a fault tolerant variable speed induction motor having three phase circuits, comprising:
- means responsive to torque and flux current command signals for providing first and second current command signals;
- means for converting the first and second current command signals to a three-phase output with sinusoidally varying signals;
- means for modifying the three-phase output and for providing a modified three-phase output which enables the motor to operate even if one of the phase circuits is open;
- means responsive to the modified three-phase output for providing first, second and third gate logic signals;
- and
- means responsive to the first, second and third gate logic signals driving the motor.
A method for providing a drive arrangement for a fault tolerant variable speed induction motor having three phase circuits, comprising:
- responding to torque and flux current command signals for providing first and second current command signals;
- converting the first and second current command signals to a three-phase output with sinusoidally varying signals;
- modifying the three-phase output to enable the motor to operate even if one of the phase circuits is open;
- responding to the modified three-phase output for providing first, second and third gate logic signals;
- and
- driving to motor in response to the first, second and third gate logic signals.
The method as described by 10, including:
- averaging the three phase current outputs for providing three zero sequence components of the three phase current outputs;
- adding the three zero sequence components with respective signals of the sinusoidally varying signals for providing three added signals;
- providing BIT outputs, each of which corresponds to one of the three phases;
- and
- multiplying each of the outputs from the three bit modules with a respective added signal for providing the modified three-phase output.
A drive arrangement for a fault tolerant variable speed induction motor having three phase circuits, comprising:
- means responsive to torque and flux current command signals for providing first and second current command signals;
- means for converting the first and second current command signals to a three-phase output with sinusoidally varying signals;
- means for modifying the three-phase output to provide a modified three-phase output which comprises an average of said three phase output and three zero sequence components that enable the motor to operate even if one of the phase circuits is open;
- means responsive to the modified three-phase output for providing first, second and third gate logic signals;
- and
- means responsive to the first, second and third gate logic signals driving the motor.
Dependencies are inferred from the claim text.