Patent ID: 8159163
Filing Date: 2012-04-17
Classification: H02P

Abstract:
1. A phase current estimation device of a motor, the phase current estimation device comprising: an inverter which uses a pulse width modulation signal to sequentially commutate an electric flow to a motor of a three-phase alternating current; a pulse width modulation signal generation unit generating the pulse width modulation signal from a carrier signal; a control unit performing a startup control and a self control of the motor using the inverter; a direct current sensor detecting a direct current of the inverter; and a phase current estimation unit estimating a phase current based on the direct current detected by the direct current sensor, wherein the control unit performs a feedback control while the startup control and the self control are performed, so that a first deviation between a control command value and a control detection value corresponding to the control command value equals zero, the control command value being based on a second deviation between a modulation factor of the inverter and a predetermined modulation factor lower limit value, the predetermined modulation factor lower limit value being a lower limit of a modulation factor range in which the phase current estimation unit is capable of estimating the phase current.