Time-scale separation approach to PWM-nonlinear control system design

The output setpoint feedback stabilization and output tracking control problems for nonlinear systems with pulse-width modulated (PWM) control variable are discussed. An equivalent continuous-time dynamics of a high-frequency pulse-width modulated nonlinear system is used for continuous-time controller design in accordance with Filippov's average approach. The proposed controller design methodology is based on time-scale separation technique (singular perturbation technique) where two-time-scale motions are induced in the closed-loop system. The closed-loop system stability, the almost perfect output tracking and external disturbance rejection are provided by selection of controller parameters. Numerical example and simulation results are presented.