Study on Nonlinear Phenomena in Buck-Boost Converter with Switched-Inductor Structure

Abstract EN

The switched-inductor structure can be inserted into a traditional Buck-Boost converter to get a high voltage conversion ratio.

Nonlinear phenomena may occur in this new converter, which might well lead the system to be unstable.

In this paper, a discrete iterated mapping model is established when the new Buck-Boost converter is working at continuous conduction current-controlled mode.

On the basis of the discrete model, the bifurcation diagrams and Poincare sections are drawn and then used to analyze the effects of the circuit parameters on the performances.

It can be seen clearly that various kinds of nonlinear phenomena are easy to occur in this new converter, including period-doubling bifurcation, border collision bifurcation, tangent bifurcation, and intermittent chaos.

Value range of the circuit parameters that may cause bifurcations and chaos are also discussed.

Finally, the time-domain waveforms, phase portraits, and power spectrum are obtained by using Matlab/Simulink, which validates the theoretical analysis results.