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

Abstract

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 nonidealities on controller design, an internal model control PID controller is designed for ideal, semi-non-ideal and complete nonideal 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.

Investigating of bidirectional dc–dc converter in different operational modes and designing of component considering the minimum OVR and filter size

“…Meanwhile, there is no attention on the OVR. The process of designing in [27] is simple. There is no need to apply any auxiliary circuits for reduction of the OVR.…”

“…There is no need to apply any auxiliary circuits for reduction of the OVR. In [27], the main objective is the reduction of the ripple without considering the filter size. The design method is based on the output capacitor and equivalent series resistance of the capacitor, although there is no attention on the inductance of the inductor and its effect on the OVR.…”

“…In [25], a control strategy design is required which causes complexity. In [27], the effect of parasitic elements on a low-power dc-dc buck-boost converter is analysed. The design method is based on the output capacitor and equivalent series resistance of the capacitor and there is no attention on the inductance value of the inductor and its effect on the OVR.…”