Practical Multivariable Controllers in Continuous‐time

This chapter introduces two types of practical multivariable controllers. These controllers are capable of tracking step reference signals and rejecting low frequency disturbances. The chapter focuses on the classical controller by considering the effect of disturbance in the controller design, leading to a practical multivariable controller that has integral action in addition to an anti‐windup mechanism in implementation. It provides both MATLAB and Simulink tutorials and details a case study of drum boiler control. The well‐known classical approach to include integral action using state space model is to introduce the integrated output in the design model. However, this approach has the integrator windup problem when the control signal reaches its saturation limits. Another classical approach to obtain integral action is through disturbance estimation where the disturbance is assumed to be a constant. The chapter presents a case study of drive train control of a wind turbine using both practical approaches.