Patent ID: 8384323
Filing Date: 2013-02-26
Classification: H02P

Abstract:
1. A motor magnetic-pole-position estimating apparatus comprising: a command voltage output device configured to output a command voltage to apply current to a motor; a current detector configured to detect an actual current applied to the motor and to output a detection result; a model-current calculator configured to calculate a model current corresponding to a voltage equation for a predetermined model of the motor based on the command voltage and the actual current, and configured to output a calculation result; a current-difference calculator configured to calculate a current difference between the model current and the actual current; first and second magnetic-pole-position-difference calculators configured to perform different operations, each of the first and second magnetic-pole-position-difference calculators being configured to calculate a magnetic-pole-position difference between an actual magnetic-pole position of the motor and an estimated or designated magnetic-pole position based on the current difference depending on whether or not a rotation speed of the motor is lower than a predetermined value; and a magnetic-pole-position calculation device configured to calculate the magnetic-pole position of the motor based on the magnetic-pole-position difference calculated by the first or second magnetic-pole-position-difference calculator.