An Improved Anti-windup Control Using a PI Controller

In this study, we have proposed an improved anti-windup control using a Proportional-Integral (PI) controller. PI control has been widely used for the industrial applications. However, PI controller is usually designed in a linear region ignoring the saturation-type nonlinearity. An anti-windup control comprises a linear feedback controller that satisfies the desired non-saturation specification and an anti-windup compensator that operates during the saturation. This control method prevents large overshoots caused by the windup phenomenon. However, since the controlled plant is not type-1, steady-state errors can occur and the input to the integral action is limited. To avoid these problems, we transformed the controlled system into a type-1 plant. Therefore, no steady-state errors occur when using a type-0 plant and the output converges to the target value.