Control of $N$-Connected Current-Programmed Independent-Input Series-Output Boost DC-DC Converters

This work is concerned with the closed-loop control of a modular current-programmed independent-input series-output (IISO) boost dc-dc converter operating in the continuous conduction mode. Each module is supplied from an independent power source and has its own current and voltage feedback loops. A Matlab/Simulink-based averaged small-signal model is developed to study the module control-to-output voltage frequency responses with current loops closed and voltage loops open. Based on these responses the model is updated with a type-2 compensated error amplifier in the voltage loop of each module. The compensator is designed for the maximum number of modules to ensure system stability when lower number of modules is used. Closed-loop responses due to step changes in load current and module input voltage show equal load-voltage sharing among the modules. All model predictions are validated using cycle-by-cycle simulations.