Patent ID: 7138777
Filing Date: 2006-11-21
Classification: H02P

Abstract:
1. A sensorless motor drive apparatus, comprising: a rectifier for rectifying an AC (Alternating Current) voltage generated from an AC power source to a DC (Direct Current) voltage; an inverter for receiving the DC voltage from the rectifier, and converting the received DC voltage into a three-phase AC voltage; a current detector for detecting a value of a current transmitted from the inverter to a motor; a controller for estimating a rotation speed and a rotor position of the motor using voltage and current signals applied to the motor, and transmitting a control signal to the inverter to control the motor; and a position estimation error detector for determining the presence or absence of a position estimation error of the motor using the current value detected by the current detector and the rotor position estimated by the controller, the position estimation error detector sending an error signal to the controller at the presence of the position estimation error of the motor, wherein the position estimation error detector includes a three-phase/stationary coordinate system converter for converting three-phase current values (Iu,Iv, and Iw) detected by the current detector into stationary coordinate system current values (i