[PIC] How to use PID controller to control PWM in dsPIC30f2010 to generate sinewave

[Heram]

I have generated sine wave using PWM. Now I want to control the output voltage using PID controller technique with less THD.
I tried in many ways but I am not getting proper output(the sine wave disturbed).
Would you please guide me ?

I have taken Kp=0.1 and Ki=0.1

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Code C - [expand]
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error = setPoint-Feedback_Value;
 
iError +=error;
 
outPut = (Kp*error) + (Ki * iError);  // PI value
 
percentage = ((outPut*100/setPoint)); //Error in percentage
 
PDC1 += ((PDC1*percentage)/100); // I have used a variable in place of PDC1 for calculation and in next step I added that to PDC1

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[KlausST]

Hi,

I think the error is in line 7.

You must not divideby "Setpoint" but by "full scale value"

Klaus

 

[KlausST]

Hi,

please limit the value of iError.
decide on your own what max and what min values make sense.

Maybe in your case limit it to 0...1.

Klaus