Field oriented control of permanent magnet synchronous motor with constant power factor control loop

A method for Field Oriented Control (FOC) of a Permanent Magnet Synchronous Motor (PMSM) with a constant Power Factor Control (PFC) Loop comprising:

• measuring a rotor position of the PMSM;
• controlling a plurality of stator voltages of the PMSM with a required direct (d)-axis current, a required quadrature (q)-axis current, the rotor position and a plurality of measured stator currents of the PMSM in a three-phase stationary reference frame;
• and
• determining the required d-axis current with a required power factor, the plurality of measured stator currents transformed into a two-phase stationary reference frame, the measured stator currents transformed into a rotational reference frame to generate a measured d-axis current and a measured q-axis current, and each of a required d-axis voltage and a required q-axis voltage transformed into the two-phase stationary reference frame, wherein the required d-axis voltage is determined with a d-axis Proportional Integral (PI) controller configured to suppress to a zero value a d-axis error between the required d-axis current and a measured d-axis current and the required q-axis voltage is determined with a q-axis PI controller configured to suppress to the zero value a q-axis error between the required q-axis current and a measured q-axis current, and wherein a power factor of the PMSM is controlled to be equal to the required power factor,
• wherein determining the required d-axis current further comprises determining a voltage vector position from an atan 2 function of the required β-axis voltage divided by the required a-axis voltage.

A method for Field Oriented Control (FOC) of a Permanent Magnet Synchronous Motor (PMSM) with a constant Power Factor Control (PFC) Loop comprising:

• determining a voltage vector position from an atan 2 function of a required β-axis voltage transformed into a two-phase stationary reference frame divided by a required a-axis voltage transformed into the two-phase stationary reference frame, wherein the required β-axis voltage is determined by an Inverse Park transformation of a required q-axis voltage with an electrical rotor position and the required α-axis voltage is determined by the Inverse Park transformation of a required d-axis voltage with the electrical rotor position, wherein the required q-axis voltage is determined by a q-axis Proportional Integral (PI) controller configured to suppress to a zero value a q-axis error between a required q-axis current and a measured q-axis current and the required d-axis voltage is determined by a d-axis PI controller configured to suppress to the zero value a d-axis error between a required d-axis current and a measured d-axis current;
• transforming a pair of currents in the two-phase stationary reference frame with the voltage vector position with a first Park transformation to determine a measured direct voltage (dv)-axis current in a voltage vector reference frame, wherein the pair of currents in the two-phase stationary reference frame is determined by transforming a plurality of stator currents of the PMSM with a Clarke transformation;
• determining a required dv-axis current in the voltage vector reference frame comprising multiplying a stator current of the PMSM with a required power factor phase shifted by a phase shift, wherein the stator current is determined from a square root of a sum of a square of each of the measured d-axis current and the measured q-axis current, wherein the measured d-axis current and the measure q-axis current are generated by transforming the pair of currents in the two-phase stationary reference frame into a rotational reference frame with the electrical rotor position of PMSM using a second Park transformation;
• and
• determining the required d-axis current by a dv-axis PI controller suppressing to the zero value a dv-axis error between the measured dv-axis current in the voltage vector reference frame and the required dv-axis current in the voltage vector reference frame.

A method for Field Oriented Control (FOC) of a motor with a constant Power Factor Control (PFC) Loop comprising:

• using a dv-axis Proportional Integral (PI) controller to suppress to a zero value a dv-axis error between a measured dv-axis current in a voltage vector reference frame and a required dv-axis current in the voltage vector reference frame to determine a required d-axis current, wherein the required d-axis current controls a plurality of stator voltages of the motor to achieve a power factor defined by a required power factor, and wherein:
• the measured dv-axis current in the voltage vector reference frame is determined by transforming a pair of currents in a two-phase stationary reference frame with a voltage vector position through a first Park transformation, wherein the pair of currents is determined by transforming a plurality of stator currents of the motor with a Clarke transformation;
• the voltage vector position is determined from an atan 2 function of a required β-axis voltage transformed to the two-phase stationary reference frame divided by the required α-axis voltage transformed into the two-phase stationary reference frame, wherein the required β-axis voltage is determined by an Inverse Park transformation of a required q-axis voltage with an electrical rotor position and the required α-axis voltage is determined by the Inverse Park transformation of a required d-axis voltage with the electrical rotor position, wherein the required q-axis voltage is determined by a q-axis PI controller configured to suppress to a zero value a q-axis error between a required q-axis current and a measured q-axis current and the required d-axis voltage is determined by a d-axis PI controller configured to suppress to the zero value a d-axis error between the required d-axis current and a measured d-axis current;
• and
• the required dv-axis current in the voltage vector reference frame is determined from the required power factor and from the pair of currents transformed into a rotational reference frame with a second Park transformation to generate a measured d-axis current and a measured q-axis current.