In general, PI(D) controllers are used to eliminate the error between the Process Variable (signal to be regulated), and the Set Point (target) by manipulating a Control Variable.
Here are the screenshots where I can see PI(D) controllers used in the post: Please refer to Figure 1 in the attached files
Input to the PI controller, Error = Torque Command – Motor Current.
Output of the PI controller looks like PWM Duty Cycle, this is then modulated by the PWM Modulator.
This means that the Motor Current (process variable) is being controlled to be close to the Torque Command (set point) value by changing the PWM Duty Cycle (control variable). Please refer to Figure 2 in the attached files
PI Controller 1 Input = Isd_ref – Isd
PI Controller 1 Output = Vsd_ref
PI Controller 2 Input = Isq_ref – Isq
PI Controller 2 Output = Vsq_ref
The current components Isd and Isq are controlled. These are our Process Variables.
Isd, also known as the Direct Current, is normally referred to as the Flux- Producing current.
Isq, also known as the Quadrature Current, is normally referred to as the Torque- Producing current.
These two current components are controlled to approach the set reference points: Isd_ref, and Isq_ref. These are our Set Points.
The control variables (PI controller output) are the stator voltage component Vsd_ref and Vsq_ref.
The two stator voltage components are then processed using the Inverse Park Transform and SV PWM to convert them into actual duty cycles used to control the 3-phase inverter.
In this manner, the Torque and Flux are indirectly controlled by changing Isq and Isd.
In general, PI(D) controllers are used to eliminate the error between the Process Variable (signal to be regulated), and the Set Point (target) by manipulating a Control Variable.
Here are the screenshots where I can see PI(D) controllers used in the post: Please refer to Figure 1 in the attached files
Input to the PI controller, Error = Torque Command – Motor Current.
Output of the PI controller looks like PWM Duty Cycle, this is then modulated by the PWM Modulator.
This means that the Motor Current (process variable) is being controlled to be close to the Torque Command (set point) value by changing the PWM Duty Cycle (control variable). Please refer to Figure 2 in the attached files
PI Controller 1 Input = Isd_ref – Isd
PI Controller 1 Output = Vsd_ref
PI Controller 2 Input = Isq_ref – Isq
PI Controller 2 Output = Vsq_ref
The current components Isd and Isq are controlled. These are our Process Variables.
Isd, also known as the Direct Current, is normally referred to as the Flux- Producing current.
Isq, also known as the Quadrature Current, is normally referred to as the Torque- Producing current.
These two current components are controlled to approach the set reference points: Isd_ref, and Isq_ref. These are our Set Points.
The control variables (PI controller output) are the stator voltage component Vsd_ref and Vsq_ref.
The two stator voltage components are then processed using the Inverse Park Transform and SV PWM to convert them into actual duty cycles used to control the 3-phase inverter.
In this manner, the Torque and Flux are indirectly controlled by changing Isq and Isd.