Patent ID: 8004222
Filing Date: 2011-08-23
Classification: H02P

Abstract:
1. A sensorless motor controller for controlling the operation of a motor/load, the motor controller comprising: an inverter having a plurality of transistors selectively controlled to convert a direct current (dc) signal to an alternating current (ac) signal that is provided to a motor/load, the ac signal having a motor drive component and a high-frequency carrier signal component; a first sense circuit connected to monitor response of the motor/load to the high-frequency carrier signal provided by the inverter to the motor/load; a sensorless circuit connected to calculate a rotor position estimate associated with the motor/load based on the monitored response of the motor/load to the high-frequency carrier signal; a motor controller connected to calculate the motor drive component of the ac signal provided to the motor/load based, at least in part, on the rotor position estimate provided by the sensorless circuit; a second sense circuit connected to monitor the high-frequency carrier signal component of the ac signal provided by the inverter to the motor/load; and a negative sequence feedback circuit connected to detect unbalances in the high-frequency carrier signal component monitored by the second sense circuit based on an analysis of negative sequence components of the high-frequency carrier signal component, wherein the negative sequence feedback circuit generates a closed-loop feedback signal that is combined with a high-frequency command signal, the combination being provided to the inverter to generate a balanced high-frequency carrier signal to be provided to the motor/load as the high-frequency carrier signal component.