PLL with TI F28379D

I am trying to implement a PLL with the TI C2000 F28379D. In my model I am using the ADC to sample a voltage (60 HZ) and then I am feeding that signal to the "sinusoidal Measurement (PLL)" block. From here I am sending the outputs of this block and the sampled Voltage back to my host computer using serial. This sampled voltage comes through as expected but the outputs of the PLL are not correct at all. When I collect the sampled voltage and then run it into the PLL block in an offline manner it outputs the expected values.

I know the issue isn’t with the data collection or serial because we have done other things using this same serial communication method and it has all worked fine. I am concerned that the PLL block is not able to work in a real time manner and only in an offline manner.

Has anyone else had any experience with the PLL in this way? The end goal is to have a self-synchronized inverter using the TI C2000 as the controller with MATLAB/Simulink are the code generation platform.

Answer 1

[Nikhilesh]

Hi Noah,

It's difficult to determine the exact cause of your issue, but I can provide some general advice on troubleshooting a PLL implementation on the TI C2000 F28379D.

Firstly, make sure that you have configured the PLL block correctly in your Simulink model. Check that the input signal to the PLL block has the correct amplitude and frequency, and that the PLL parameters (such as loop filter coefficients and NCO frequency) are set appropriately for your application.

Next, check the sample rate of your ADC and make sure that it is fast enough to capture the frequency components of the input signal. You may need to adjust the ADC settings or use a higher sampling rate to accurately capture the 60 Hz signal.

If you are still experiencing issues, try running the Simulink model in simulation mode with a fixed-step solver and a small time step (e.g. 1 microsecond). This will allow you to see the behavior of the PLL block in real-time and identify any issues with its performance.