One-cycle control of switching converters

A pulsed nonlinear control technique, one-cycle control, is introduced. This technique takes advantage of the pulsed and nonlinear nature of switching converters and achieves instantaneous control of the average value of the chopped voltage or current. This technique provides fast dynamic response and good input-perturbation rejection. It is suitable for the control of pulsewidth-modulated (PWM) converters and quasi-resonant converters. The one-cycle control theory is developed based on the analysis of the basic buck converter with conventional feedback control and current-mode control. Experiments were conducted to verify the feasibility of one-cycle control of the buck converter. The dynamic behavior of one-cycle controlled switching converters is studied. The Cuk converter is used as an example for the analysis and experiments. The one-cycle control theory is generalized to control all types of switching converters: constant frequency, constant turn-on time, constant turn-off time, and variable switches.