A Comparative Analysis Between $\text {H}_{\infty}$ and Sliding Mode Controllers on Automatic Voltage Regulator System

This study addresses the design of two robust controller types for automatic voltage regulators (AVRs): $\text {H}_{\infty}$ and sliding mode controllers (SMC). Two AVR transfer function models were studied- the third-order model and the second-order approximate model. The AVR's performance criteria included rise time, settling time, overshoot percentage, and ITAE (Integral Time Absolute Error). A tan hyperbolic function was used to lessen the chattering effect in SMC. In terms of parametric uncertainties, SMC was found more robust than the H-infinity controller. The effect of injecting disturbance in the system was also studied. The entire design and simulation was done through the MATLAB Simulink software.