Patent ID: 9729097
Date: 2017-08-08
CPC Classifications: H02P

Claim:
1. An apparatus for controlling a motor, the apparatus comprising: a generator configured to generate a d-axis current command and a q-axis current command of a synchronous reference frame; a current controller configured to output a d-axis voltage and a q-axis voltage of the synchronous reference frame, by performing a proportional and integral control, from the d-axis current command and the q-axis current command of the synchronous reference frame; a first conversion unit configured to convert the d-axis voltage and the q-axis voltage of the synchronous reference frame received from the current controller, to a d-axis voltage and a q-axis voltage of a stationary reference frame; an inverter configured to output a voltage to control a motor, from the d-axis voltage and the q-axis voltage of the stationary reference frame received from the first conversion unit; a second conversion unit configured to convert a phase current outputted from the inverter to a d-axis current and a q-axis current of the synchronous reference frame; an estimation unit configured to estimate a speed and a position of a rotor of the motor, based on the phase current outputted from the inverter, and based on the d-axis voltage and the q-axis voltage of the stationary reference frame outputted from the first conversion unit; and a correction unit configured to correct the d-axis current command and the q-axis current command of the synchronous reference frame received from the generator and to provide the corrected the d-axis and q-axis current commands for the current controller, by using the d-axis current command and the q-axis current command of the synchronous reference frame received from the generator and the speed of the rotor received from the estimator, wherein the correction unit decreases the d-axis current command of the synchronous reference frame received from the generator, increases a slip frequency in response to the decreased d-axis current command of the synchronous reference frame, and accelerates a rotor magnetic flux angle in response to the increased slip frequency, wherein the correction unit includes a determination unit configured to determine a constant K to be applied to the d-axis current command of the synchronous reference frame; a first calculation unit configured to multiply the d-axis current command of the synchronous reference frame received from the generator by the constant K; and a second calculation unit configured to multiply the q-axis current command of the synchronous reference frame received from the generator by an inverse number of the constant K, and wherein the determination unit determines the constant K so that the constant K is satisfied in a range of Max(K where Max function is a function to seek a maximum value, min function is a function to seek a minimum value, and each of K