Method and system for controlling permanent magnet synchronous motor

A method for controlling a current of a permanent magnet synchronous motor, comprising:

• generating a torque command based on a difference between an angular velocity command and an angular velocity calculated based on a rotor absolute angular position of the permanent magnet synchronous motor;
• generating d-axis and q-axis current feedback signals based on a drive current of the permanent magnet synchronous motor and the rotor absolute angular position of the permanent magnet synchronous motor;
• generating a fundamental d-axis voltage command based on a difference between a d-axis current command and the d-axis current feedback signal and a fundamental q-axis voltage command based on a difference between a q-axis current command, which is calculated based on the torque command, and the q-axis current feedback signal;
• generating a harmonic suppression d-axis voltage command and a harmonic suppression q-axis voltage command for suppressing at least one higher-order harmonic current component included in a harmonic current component;
• generating a d-axis voltage command by adding the fundamental d-axis voltage command and the harmonic suppression d-axis voltage command and a q-axis voltage command by adding the fundamental q-axis voltage command and the harmonic suppression q-axis voltage command;
• transforming the q-axis voltage command and the d-axis voltage command into three-phase voltage commands;
• and
• outputting a drive voltage for driving the permanent magnet synchronous motor based on the three-phase voltage commands.

A system for controlling a permanent magnet synchronous motor, comprising:

• means for generating a torque command based on a difference between an angular velocity command and a rotor angular velocity calculated based on a rotor absolute angular position of the permanent magnet synchronous motor;
• means for generating a q-axis current command and a d-axis current command corresponding to the torque command;
• means for generating a d-axis current feedback signal and a q-axis current feedback signal based on a drive current applied to the permanent magnet synchronous motor and the rotor absolute angular position;
• means for generating a fundamental d-axis voltage command and a fundamental q-axis voltage command, a harmonic suppression d-axis voltage command and a harmonic suppression q-axis voltage command which are used to suppress at least one higher-order harmonic current component included in a harmonic current component, and generating a d-axis voltage command by adding the fundamental d-axis voltage command and the harmonic suppression d-axis voltage command and a q-axis voltage command by adding the fundamental q-axis voltage command and the harmonic suppression q-axis voltage command;
• means for transforming the q-axis voltage command and the d-axis voltage command into three-phase voltage commands;
• and
• means for outputting a drive voltage for driving the permanent magnet synchronous motor based on the three-phase voltage commands.