Generalization of a nonlinear average current control method for CCM and DCM operation

The recently developed nonlinear average current control method is generalized to discontinuous conduction mode (DCM) of operation. Steady state and dynamic characteristics of the generalized control method are analyzed by sample-data as well as averaged models. Analysis and measurement results demonstrate that the resulting current loop is always stable and can achieve single-cycle transient to step changes in the reference current. Performance of the control method is also compared with conventional linear average current control, and applications of the method in dc-dc and single-phase PFC converters are demonstrated. A unified implementation of the control method for automatic detection and transition between CCM (continuous conduction mode) and DCM operation is also presented.