Patent ID: 9077278
Filing Date: 2015-07-07
Classification: H02P

Abstract:
1. An AC motor control apparatus for a system, which includes a three-phase AC motor having a first phase, a second phase and a third phase, and a current sensor for sensing a current flowing in the first phase, the AC motor control apparatus comprising: a current estimating part configured to calculate an estimated current of at least the second phase based on a sensed current of the first phase and electrical angle of the AC motor and calculate a d-axis estimated current and a q-axis estimated current in a rotating coordinate system of the AC motor based on the sensed current of the first phase and the estimated current of at least the second phase; and a controlling part configured to control electric power supply to the AC motor by using the d-axis estimated current and the q-axis estimated current, wherein the current estimating part includes an interpolation part configured to interpolate the estimated current of at least the second phase by fixing a command related to a voltage of the AC motor and holding the estimated current at previous or older values thereof at a zero-crossing time of the sensed current of the first phase, the zero-crossing time including a case in which the current detection value of the first phase is 0 or in a predetermined range including 0.