Simple design strategy for modular input-series output-series converters

This paper analyzes the behavior of a modular system of DC/DC converters with input-series output-series connections. Modularization is a good alternative to provide higher voltage capability, reduce the cost by using the same module to build different power converters or even increase the performance in some cases. However, the control of the converters should be considered carefully, since the system becomes more complex and there are some unstable behaviors that must be avoided. The goal of this work is to explore a simple solution that provides an inherent stable operation thanks to the operation mode of the converters (all of them working as loss-free resistors but on that works in continuous conduction mode). This proposal allows the modular system to operate with a control scheme dramatically simplified.