Method and apparatus for determining motor rotation status
AssigneeRockwell Automation Technologies, Inc.
InventorRobert DeLange
Life of this patent
Estimating the term…
Abstract
A motor drive unit includes a voltage inverter, a controller, and reconnect logic. The voltage inverter provides motor drive signals to an associated motor. The controller is operable to generate demand signals for at least two control axes for controlling the voltage inverter. The reconnect logic is operable to direct the controller to inject a current into a first control axis. The reconnect logic is further operable to monitor a voltage of a second control axis to detect zero crossings and determine a speed of the associated motor based on the detected zero crossings.
Claims25
A motor drive unit, comprising:
- a voltage inverter for providing motor drive signals to an associated motor;
- a controller operable to generate demand signals for at least two control axes for controlling the voltage inverter;
- and
- reconnect logic operable to direct the controller to inject a current into a first control axis, the reconnect logic being further operable to monitor a voltage of a second control axis to detect zero crossings and determine a speed of the associated motor based on the detected zero crossings.
A method for controlling a motor, comprising:
- injecting a current into a first control axis of a motor drive unit coupled to the motor;
- monitoring a voltage of a second control axis to detect zero crossings;
- and
- determining a speed of the motor based on the detected zero crossings.
A motor control system, comprising:
- means for injecting a current into a first control axis of a motor drive unit coupled to the motor;
- means for monitoring a voltage of a second control axis to detect zero crossings;
- and
- means for determining a speed of the motor based on the detected zero crossings.
Dependencies are inferred from the claim text.