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US 7,298,105 B1Granted
Motor speed estimation system and method using hybrid model reference adaptive system
AssigneeRockwell Automation Technologies, Inc.
InventorsHaihui Lu, Wei Qian
Life of this patent
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Abstract
Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor speed and for estimating motor speed, in which a speed estimate controller provides a rotor speed estimate based on a first error term from a torque-based MRAS component for a first range of motor speeds and based on a second error term from a rotor flux-based MRAS component for a second range of speeds.
Claims20
A motor drive system, comprising:
- a switching system including a plurality of switching devices coupled between a power source and a motor and operative according to a corresponding plurality of switch control signals;
- and
- a motor startup control system for controlling the motor speed during startup, the motor startup control system comprising:
- a hybrid model reference adaptive system (MRAS) component including:
- a torque-based MRAS component providing a first error term at least partially according to a calculated torque value and an estimated torque value;
- and
- a rotor flux-based MRAS component providing a second error term at least partially according to a calculated rotor flux and an estimated rotor flux;
- a speed estimate controller providing a rotor speed estimate according to a controller error input;
- a motor controller providing a motor controller output for controlling the motor speed during startup according to a desired startup speed profile and according to the rotor speed estimate;
- a switch control circuit providing the switch control signals to the switching system during startup of the motor according to the controller output;
- and
- an error selector operatively coupled with the hybrid MRAS component and with the speed estimate controller to provide the error input to the speed estimate controller, the error selector providing the first error term as the controller error input when the rotor speed estimate is in a first speed range and providing the second error term as the controller error input when the rotor speed estimate is in a second speed range.
9 more elements
A control system for controlling the speed of an electric motor, comprising:
- a speed estimate controller providing a rotor speed estimate according to a controller error input;
- a hybrid model reference adaptive system (MRAS) component, including a torque-based MRAS component providing a first error term based on a calculated torque value and an estimated torque value, and a rotor flux-based MRAS component providing a second error term based on a calculated rotor flux and an estimated rotor flux;
- an error selector operatively coupled with the hybrid MRAS component and with the speed estimate controller to provide the error input to the speed estimate controller, the error selector providing the first error term as the controller error input when the rotor speed estimate is in a first speed range and providing the second error term as the controller error input when the rotor speed estimate is in a second speed range;
- and
- a motor controller providing a controller output for controlling the motor speed according to a desired speed profile and according to the rotor speed estimate.
2 more elements
A hybrid model reference adaptive system (MRAS) motor speed estimation system for estimating the speed of an electric motor, comprising:
- a speed estimate controller providing a rotor speed estimate according to a controller error input;
- a torque-based MRAS component providing a first error term based at least partially on a calculated torque value and an estimated torque value;
- a rotor flux-based MRAS component providing a second error term based at least partially on a calculated rotor flux and an estimated rotor flux;
- and
- an error selector providing the error input to the speed estimate controller according to the first error term when the rotor speed estimate is in a first speed range and providing the error input according to the second error term when the rotor speed estimate is in a second speed range.
2 more elements
A method of controlling the speed of an electric motor, the method comprising:
- providing a rotor speed estimate according to a controller error input;
- providing a controller output according to the rotor speed estimate and according to a desired speed profile;
- controlling the motor speed according to the controller output;
- computing a first error term at least partially according to a calculated torque value and an estimated torque value;
- computing a second error term at least partially according to a calculated rotor flux and an estimated rotor flux;
- and
- providing the controller error input according to the first error term when the rotor speed estimate is in a first speed range and providing the error input according to the second error term when the rotor speed estimate is in a second speed range.
4 more elements
Dependencies are inferred from the claim text.