Boundary control of boost converters using state-energy plane

The small-signal control-to-output transfer function of boost converters consists of a right-half-plane zero, which is typically the main consideration in designing the controller with classical control theories. Instead of designing the controller in frequency domain, a time-domain boundary control method for large-signal control of boost converters will be presented in this paper. By transforming the state plane into a state-energy plane to dictate the switching instants, a well-defined switching surface is derived. The converter has good output regulation, as well as good dynamic behaviors. The converter can revert to the steady state in two switching actions during the external disturbances. Of particular importance, the same controller is applicable for converter operating in all three modes, including continuous conduction mode, critical conduction mode, and discontinuous conduction mode. Theoretical predictions are verified with the experimental results of a 100W prototype.