System and method for transient-based motor speed estimation with transient excitation
First Claim
1. An AC motor control system for operating an AC induction motor, the motor control system comprising:
- a switching system including a plurality of switching devices coupled between an AC power source and an induction motor, the individual switching devices operative to selectively couple a corresponding motor lead to the AC power source according to a corresponding switch control signal;
a motor controller providing a motor controller output to control the motor speed during starting or stopping according to a desired speed profile and according to a rotor speed estimate;
a switch control system providing a plurality of switch control signals to control operation of the switching devices of the switching system during starting or stopping of the motor according to the controller output;
a transient excitation system operatively coupled with the switch control system to selectively modify at least one switch control signal to excite a motor transient; and
a transient-based speed estimation system operatively coupled with the switching system and the motor speed control system, the transient-based speed estimation system receiving at least one feedback signal or value from the switching system and providing the rotor speed estimate at least partially according to the feedback signal or value.
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Abstract
AC motor control systems and speed controllers are presented, including a transient-based speed estimation system that provides a rotor speed estimate based on a measured speed-related motor transient signal, and a transient excitation system which selectively modifies at least one switch control signal to excite the measured motor transient. The measured speed-related transient may include a phase error signal, a phase lag signal, a peak current signal, a voltage integral signal, a motor winding voltage signal, a switching device voltage, and a voltage zero crossing signal, and the switching signal modification can comprise removal of select pulse(s) from a switching control pulse stream or selective modification of spacings between pulses to re-excite the motor transient.
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Citations
34 Claims
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1. An AC motor control system for operating an AC induction motor, the motor control system comprising:
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a switching system including a plurality of switching devices coupled between an AC power source and an induction motor, the individual switching devices operative to selectively couple a corresponding motor lead to the AC power source according to a corresponding switch control signal; a motor controller providing a motor controller output to control the motor speed during starting or stopping according to a desired speed profile and according to a rotor speed estimate; a switch control system providing a plurality of switch control signals to control operation of the switching devices of the switching system during starting or stopping of the motor according to the controller output; a transient excitation system operatively coupled with the switch control system to selectively modify at least one switch control signal to excite a motor transient; and a transient-based speed estimation system operatively coupled with the switching system and the motor speed control system, the transient-based speed estimation system receiving at least one feedback signal or value from the switching system and providing the rotor speed estimate at least partially according to the feedback signal or value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A motor speed control system operatively coupled with a switching system of a motor controller to control a driven motor speed during starting or stopping, the motor speed control system comprising:
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a motor controller providing a motor controller output to control the motor speed during starting or stopping according to a desired speed profile and according to a rotor speed estimate; a switch control system providing a plurality of switch control signals to control operation of a plurality of switching devices of the switching system during starting or stopping of the motor according to the controller output; a transient excitation system operatively coupled with the switch control system to selectively modify at least one switch control signal to excite a motor transient; and a transient-based speed estimation system receiving at least one feedback signal or value from the switching system and providing the rotor speed estimate to the motor controller at least partially according to the feedback signal or value. - View Dependent Claims (19, 20, 21, 22, 23)
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24. A method for controlling the speed of an AC motor during starting or stopping, the method comprising:
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providing a plurality of switch control signals to a switching system for selective coupling of motor leads to an AC power source to control the motor speed during starting or stopping according to a desired speed profile and according to a rotor speed estimate; selectively modifying at least one of the switch control signals to excite a motor transient; measuring a transient speed-related signal associated with the motor transient; and providing the rotor speed estimate at least partially according to the transient speed-related signal. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification