DC-DC converters are nonlinear systems that can exhibit complicated phenomena, which make difficult the system behaviour analysis and the controller design. The validity of any prediction and analysis of the converter behaviour are, mainly, related to the used modelling technique. For a rigorous description, an accurate modelling technique with minimum of simplifying assumptions is needed. In this study, a more general and simple modelling method of DC-DC converters is proposed. It is based on introducing enhancements to the existing discrete modelling approach of DC-DC power converters to obtain an accurate description of the system behaviour with a minimum of simplifying assumptions and validity hypothesis of the model. Copyright © 2010 John Wiley & Sons, Ltd.