Hi Arijeet,
To address issues with your closed-loop buck converter using a PI controller:
- Check the voltage sensor accuracy and correct scaling for the TMS320F28335's ADC range.
- Start with reasonable initial values for the proportional (Kp) and integral (Ki) gains.
- Implement an anti-windup mechanism to prevent excessive integral term accumulation when the duty cycle is at its limit.
- Systematically tune Kp and Ki to achieve desired performance, using methods like Ziegler-Nichols or trial and error.
- Confirm the control loop frequency matches or is a multiple of the switching frequency.
- Apply a low-pass filter to the feedback signal if it's noisy.
- Clamp the control signal to ensure the duty cycle stays within the 0-1 range.
- Use Simulink to simulate and adjust the system based on its response to disturbances.
- If simulation works but hardware doesn't, recheck hardware connections, PWM signal, and ADC conversion.
Hope this helps you to troubleshoot your closed-loop system.
