Piecewise-linear methods for digital control of input-switched PWM systems

Pulse width modulation (PWM) is a widely used strategy for operating switch controlled power electronic circuits and systems. One method of designing digital controllers for PWM systems is based on inversion of nonlinear discrete-time maps which define the input-output relation (for output control) or the input-state relation (for state control). Unfortunately, any direct attempt to implement this type of control would generally require either a great deal of on-line computation or a very large memory space for data storage. In this paper, piecewise-linear methods are used to simplify the discrete-time map inversion process without incurring any significant degradation in accuracy. The result is that substantially improved control performance is now achievable with a better balance between computation and storage requirements.