Circuit for driving permanent-magnet synchronous motor using proportional controller

A method for controlling a permanent-magnet synchronous motor having a permanent magnet in a rotor by controlling a voltage-type inverter and performing weakening field control by decreasing a d-axis current in a direction of a magnetic flux generated by the permanent magnet in the permanent-magnet synchronous motor, comprising:

• a first step of detecting a d-axis current detection value, which is a direction value of the d-axis current and a q-axis current detection value, which is a detection value of a current component in a direction normal to the magnetic flux;
• a second step of outputting a d-axis signal proportional to a deviation between the d-axis current detection value and a d-axis current command value for the motor;
• a third step of outputting a q-axis signal proportional to a deviation between the q-axis current detection value and a torque command value for the motor;
• a fourth step of determining a d-axis voltage command value and a q-axis voltage command value respectively according to the d-axis signal and the q-axis signal;
• a fifth step of converting the d-axis voltage command value and the q-axis voltage command value into a voltage command vector in a polar coordinate format using an angle and amplitude;
• and
• a sixth step of controlling the voltage-type inverter by performing a PWM conversion on the voltage command vector.

A method for controlling a permanent-magnet synchronous motor having a permanent magnet in a rotor by controlling a voltage-type inverter and performing weakening field control by decreasing a d-axis current in a direction of a magnetic flux generated by the permanent magnet in the permanent-magnet synchronous motor, comprising:

• a first step of detecting, a d-axis current detection value, which is a direction value of the d-axis current, and a q-axis current detection value, which is a detection value of a current component in a direction normal to the magnetic flux;
• a second step of outputting a d-axis signal proportional to a time integration value of a deviation between the d-axis current detection value and a d-axis current command value for the motor when the d-axis current detection value is equal to or smaller than a predetermined value, and outputting the d-axis signal proportional to the deviation between the d-axis current detection value and the d-axis current command value when the d-axis current detection value exceeds the predetermined value;
• a third step of outputting a q-axis signal proportional to time integration of a deviation between the q-axis current detection value and a torque command value for the motor;
• a fourth step of determining a d-axis voltage command value and a q-axis voltage command value respectively according to the d-axis signal and, the q-axis signal;
• a fifth step of converting the d-axis voltage command value and the q-axis voltage command value into a voltage command vector in a polar coordinate format using an angle and amplitude;
• and
• a sixth step of controlling the voltage-type inverter by performing a PWM conversion on the voltage command vector.

A device for controlling a permanent-magnet synchronous motor having a permanent magnet in a rotor by controlling a voltage-type inverter and performing weakening field control by decreasing a d-axis current in a direction of a magnetic flux generated by the permanent magnet in the permanent-magnet synchronous motor, comprising:

• proportional control means for outputting, a d-axis signal proportional to a deviation between a d-axis current detection value which is a component in a direction of the magnetic flux generated by the permanent magnet and a d-axis current command value for the motor;
• compensating means for determining a d-axis voltage command value and a q-axis voltage command value using the d-axis signal and a q-axis signal obtained based on a deviation between a q-axis current detection value which is a component in a direction normal to the magnetic flux and a torque command value for the motor;
• coordinate converting means for converting the d-axis voltage command value and the q-axis voltage command value into a voltage command vector in a polar coordinate format using an angle and amplitude;
• and
• operating means for generating a signal for use in controlling the voltage-type inverter by performing a PWM conversion on the voltage command vector.

A device for controlling a permanent-magnet synchronous motor, comprising:

• a permanent-magnet synchronous motor comprising a permanent magnet in a rotor;
• a voltage-type inverter for supplying drive power for the synchronous motor;
• and
• a control device for performing weakening field control by controlling the voltage-type inverter to decrease a d-axis current in the permanent-magnet synchronous motor in a direction of a magnetic flux generated by the permanent magnet, comprising:
• proportional control means for outputting a d-axis signal proportional to a deviation between a d-axis current detection value which is a component in a direction of the magnetic flux generated by the permanent magnet and a d-axis current command value for the motor;
• compensating means for determining a d-axis voltage command value and a q-axis voltage command value using the d-axis signal and a q-axis signal obtained based on a deviation between a q-axis current detection value which is a component in a direction normal to the magnetic flux and a torque command value for the motor;
• coordinate converting means for converting the d-axis voltage command value and the q-axis voltage command value into a voltage command vector in a polar coordinate format using an angle and amplitude;
• and
• operating means for generating a signal for use in controlling the voltage-type inverter by performing a PWM conversion on the voltage command vector.