Hi Meenakshi RM,
I understand that you are designing a DC microgrid system that incorporates a PV array, and you want to optimize the boost converter control by tuning a cascaded PI controller. This controller should be capable of managing both the voltage control loop from an MPPT algorithm and the current tracking loop for the PV array's output.
MATLAB offers various tools to facilitate the tuning of controllers. For tuning a cascaded PI controller, you can use the Control System Toolbox, which includes functions like "pidtune" to help you find the appropriate PI controller parameters.
For example, you can use the "pidtune" function to obtain the PI controller gains for each loop. The outer voltage control loop would be tuned first, followed by the inner current loop, ensuring that the inner loop has a faster response than the outer loop.
% Create a transfer function model of your system for each loop
% For instance, Gv for the voltage loop and Gi for the current loop
Gv = tf([...], [...]); % Replace with your system's voltage loop dynamics
Gi = tf([...], [...]); % Replace with your system's current loop dynamics
% Tune the PI controller for the voltage loop
[PIv, infov] = pidtune(Gv, 'PI');
% Tune the PI controller for the current loop, ensuring a faster response
[PIi, infoi] = pidtune(Gi, 'PI', infov.Ts/10); % 10 times faster than voltage loop
% Now you can use these PI controllers in your system
You can then implement these tuned controllers in your boost converter control algorithm, where the voltage control loop sets the reference for the current control loop, which in turn controls the duty cycle of the boost converter to achieve maximum current tracking.
Refer to the documentation of the "pidtune" function for more information on tuning PI controllers:
For more understanding of designing control systems in MATLAB, refer to the documentation of the Control System Toolbox:
For implementing MPPT algorithms, you can refer to the Simulink model examples for PV systems useful:
Hope this helps!
