Designing an Induction motor from AC-DC-AC, I am not sure what code to enter for the function block. I want to check the speed and torque response with the change of frequency

Designing an AC-DC-AC induction motor so far I have:

AC source - rectifier - Inverter with the function block - Induction motor and - constant block (load). I want to check the speed and torque responce with the change of frequency.

I am not sure what code do I need to enter in the function block so that I can check the speed and toque responce with the change of frequency.

Can anyone assist please?

Regards

Answer 1

[Manikanta Aditya]

Hi,

As part of process design the AC design source and then use a diode bridge rectifier block to convert AC to DC.

• Then add a capacitor to smooth the DC voltage.
• Use a PWM inverter to convert DC back to AC with controllable frequency and voltage.
• Create a function block to control the inverter frequency and voltage.
• Configure an induction motor block with parameters like rated power, voltage, and frequency.
• Add a constant block to simulate load torque.

Here is an example workaround MATLAB code snippet for the function block that controls the frequency and voltage of the inverter:

function [Vout, Fout] = inverter_control(speed_ref, speed_actual)
    % Parameters
    Vbase = 230;   % Base voltage in volts
    Fbase = 50;    % Base frequency in Hz
    
    % Proportional controller for speed regulation
    Kp = 1.0;
    
    % Calculate the frequency error
    freq_error = speed_ref - speed_actual;
    
    % Adjust the output frequency based on the speed error
    Fout = Fbase + Kp * freq_error;
    
    % Limit the frequency within safe operating range
    Fout = max(0, min(Fout, 2*Fbase));
    
    % Adjust the output voltage proportionally to the frequency
    Vout = Vbase * (Fout / Fbase);
end

I hope this helps!