The robust design of PWM power amplifier by the approximate 2-degree-of-freedom integral type servo system

A PWM power amplifier which constitutes the feedback-control system so that the output voltage supplied to load might be proportional to a reference input is used as amplifier itself or as power supply. Then, a robust PWM power amplifier-whose transient, response characteristics do not, deteriorate to an extensive load change or direct-current power-supply voltage change is needed. Moreover. the. amplifier output. rarest be made to follow its reference input correctly in the application of an amplifier as a power supply which generates various functions. Therefore, the band width of amplifier must be specified, and, at the same time, an over-shoot in a step response is not allowed. In this paper. a. method for designing a robust controller of PWM power amplifier is proposed which can satisfy such demands. The controller constitutes an approximate 2-degree-of-freedom integral type servo system. This servo system becomes fully robust against a. large load change. Moreover. the controller obtained by this designing method is actually manufactured, and it is shown. from an experiment that a sufficiently robust control system is realizable.