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.
Type:
Grant
Filed:
April 24, 2006
Date of Patent:
June 5, 2007
Assignee:
Rockwell Automation Technologies, Inc.
Inventors:
Haihui Lu, Thomas A. Nondahl, David M. Messersmith