Steady state and averaged state space modelling of non-ideal boost converter

Abstract

Switched mode power converters are the most important circuits for battery powered applications such as hybrid electric vehicles, lighting systems as well as integrated circuits. These converters are usually studied in its ideal form. However, practical converters behave differently due to associated parasites and thus affect both steady state and stability. So, this paper analyses steady state and state space modelling of non-ideal boost converter. A converter is operated in both CCM and DCM modes. Models are derived by considering capacitance effects of diode and switch in addition to other parasites. The models derived are detailed and care has been taken to avoid assumptions and approximations though the models are very complex. The methodology adopted can be easily extended for other converters. Effect of every parasite and switching frequency on performance of the converter are clearly evaluated by plotting time domain and frequency domain plots in MATLAB. Simulation results show that there is a considerable deviation in performance of practical converters from its ideal case and the deviation is just not due to the inclusion of parasites but also due to the shift in operating point (duty cycle).