ADC_PID_EPWM simulation

Hi Community members,

I am a beginner in PID simulation.

I use ADC block to generate a voltage/digital number at Time Scope0. but it gives 0 values all the time. Why?

PID is tuned by Automatic generator and then I can get the results at Time Scope 4,5,6.

Vref is 2V which is compared with my ADC values through Adder/Subtractor. the result of Adder/Subtractor is shown in Time Scope3 .

The Problem is why do i get always 0 amplitude at Time Scope0? Is there any problem in ADC settings to run the simulation?

MATLAB2021b version

Please suggest to simulate this PID based ADC conversion and genrating ePWM signals.

Thanks

Kind Regards

Arsalan

[Muhammad Arsalan Athar]

@MathWorks Support Team @MATLABacademy @MathWorks Simulink Team

Answer 1

[Anudeep Kumar]

Hey Muhammad,

I tried to reproduce your model based on the figure and tried to dig deeper in the issue you are facing. I believe there could be two possible reasons :

1. ADC Block output is Always zero: You need to check if the ADC block is configured correctly based on your board’s configuration and what output is it producing. Check the reference voltage, resolution and other properties and the input to it.
2. Zero-Order Hold Block: The Zero order hold block samples its input at a specified interval. If the sample time is not aligned with the simulation, or the input is always zero at the sample instant, the output will be 0. So make sure the sample time of the zero order hold block is configured correctly.

I am attaching here the documentation for the ADC and the ZOH block for better understand how to configure them to achieve your goal.

https://www.mathworks.com/help/releases/R2021b/simulink/slref/zeroorderhold.html

https://www.mathworks.com/help/releases/R2021b/ti-c2000/ref/adctype0.html

In addition, I am attaching a few examples and a MATLAB Answer link that might help you simulate PID based ADC conversion and generate EPWM signal.

How to convert PID output Signal to a PWM signal in simulink? :

https://www.mathworks.com/matlabcentral/answers/404873-how-to-convert-pid-output-signal-to-a-pwm-signal-in-simulink

ADC-PWM Synchronization using ADC Interrupt:

https://www.mathworks.com/help/ti-c2000/ug/adc-pwm-synchronization-via-adc-interrupt.html

Control Peripherals Examples:

https://www.mathworks.com/help/ti-c2000/examples.html?s_tid=CRUX_topnav&category=control-peripherals

Hope the above links guide you in the right direction.