On the design of pulse width modulation controllers for linear dynamical systems

A method is proposed for the design of pulse-width-modulation (PWM) feedback controllers regulating linear dynamical plants. The design is carried out on the basis of an infinite frequency average model of the actual closed loop controller system which retains all the essential qualitative features of the discontinuous controlled system. The average closed loop system results in the same original plant controlled by a memoryless nonlinearity. This fact allows the use of classical control time domain design techniques in the specification of the PWM controller parameters. An alternative frequency domain approach is proposed for the study of the stability of PWM feedback controllers. Several illustrative examples are presented