A stability analysis method based on Floquet theory for multi-stage DC-DC converters system

The stability analysis of multi-stage DC-DC converters system is a big challenge, since the interaction among the individual converters can lead to an instability of the whole system. This paper applied the stability analysis method based on Floquet theory for a three-stage DC-DC converters system. In this paper, the stability analysis method based on Floquet theory is reviewed at the beginning. Following, the Floquet theory is employed into the stability analysis of multi-stage DC-DC converters. A three-stage buck converters with independent voltage control loops is taken as an example and the Floquet criterion is applied. Finally, the accuracy of the stability analysis method based on Floquet theory is verified by PSIM simulation and experimental results. The stability analysis method based on Floquet theory is convenient to determine whether a multi-stage DC-DC converters system can work stably at any given steady-state operating points.