Table 1 Comparison of PI controller and model reference adaptive controller.
From: A model reference based adaptive controller for power flow management in microgrid systems
Aspects | PI controller | Model reference adaptive controller (MRAC) |
|---|---|---|
Approach | Stability boundary locus approach; feedback control loop that calculates an error signal by taking the difference between the output of a system22 | Optimal control strategy that constantly controls parameters to optimize the results in real time27 |
Error | Improves the response of the control system by reducing the steady-state error22 | If model matching conditions are met, then error will be equal to zero, minimizing the error obtained29 |
Implementation | Output is proportional to input and is integral of input signal; therefore, it provides a faster response time19 | A reference model is chosen which matches with the closed-loop system26 |
System models | Corrects for the error between the commanded setpoint and the actual value based on some type of feedback22 | Changes the gain of the controller as the system moves between states26 |
Stability analysis | Does not depend on the stability of the system-less stable22 | Improves the overall stability of the system26 |
Robust controller | Less robust, needs additional mechanisms to improve robustness22 | Self-tune controller that works well with all variations26 |
Complexity | Controller has two tuning parameters to adjust, hence it’s a challenge to the system22 | Less complex as the system adapts to variations in the system dynamics26 |
Result accuracy | Good22 | Strong in nature26 |
Applications | Automatic movements of machines, systems22 | Automatic adjustments of machine systems26 |
