Decoupling control and closed-loop design of buck multi-level converter

The Multi-Level (ML) converter can reduce the voltage stress of the power switches with the use of the flying capacitors. However, the ML converter is a multi-input multi-output, strongly coupled system. The model of the Buck ML converter was built. The control strategy proposed lately was employed to decouple the converter into several independent single-input single-output systems and design the closed-loop control scheme for the systems. The Buck Three-Level (TL) converter was taken as the example to illustrate the design and verified by the experiment. The experimental results show that the modeling and design is valid and the flying capacitor voltage control is independent of the output voltage control.