Low‐power non‐ideal pulse‐width modulated DC–DC buck–boost converter: design, analysis and experimentation

In this study, parasitic elements (non‐idealities) effect on a low‐power DC–DC buck–boost converter design is analysed and investigation is carried out by both large (i.e. steady‐state) and small signal analysis. The large signal analysis of non‐ideal buck–boost converter explored the significant information such as nearly accurate duty cycle, maximum allowable duty cycle and maximum possible output voltage. Further, accurate mathematical design formulae are derived of inductor and capacitor for specified inductor current ripple and output voltage ripple (OVR), respectively. Moreover, consequences of different equivalent series resistance of capacitor on OVR is examined. Subsequently, the exact model of buck–boost converter is procured from the small signal analysis, which is almost analogous to practical system. In order to show the impact of non‐idealities on controller design, an internal model control PID controller is designed for ideal, semi‐non‐ideal and complete non‐ideal systems based on their respective models, which shows the controller based on non‐ideal model provides very close results to practical system. Conclusively, the complete theoretical explorations are justified by simulations and substantiated by experimental results.