A tutorial on PI velocity control of induction motors

This paper presents vector-based PI control of induction motors in a tutorial style. Based on a general nonlinear model for induction motors, a cascade control structure is proposed for velocity control, where the inner-loop systems are designed using proportional controllers with dynamic decoupling whilst the outer velocity loop is controlled by PI controller. Desired closed-loop performance parameters, such as desired bandwidth and closed-loop gain, are used for selection of the controller parameters. Robustness of the control system against parameter variations is characterized using gain and phase margins of the closed-loop system. Experimental results are obtained to illustrate the design.