Control and Optimization of ${N}$ -Port DC–DC Converters

Multiport dc-dc converters offer an efficient approach for combining several energy sources under a centralized supervisory controller. In this brief, a systematic approach to the design and implementation of a centralized controller for N-port dc-dc converters is presented. An optimization algorithm associated with such a controller is also proposed, which offers the flexibility to meet the desired control and energy optimization objectives. More specifically, the controller is a robust linear feedback controller (LFC) based on state-space design and the optimization algorithm is implemented using sequential quadratic programming (SQP). Newton's algorithm is also introduced to obtain approximated solutions to the controlled inputs and to initialize the SQP algorithm. The implementation of the LFC and SQP algorithm is demonstrated, simulated for performance evaluation, and then validated using a hardware prototype for a four-port dc-dc converter. The optimization algorithm yields a 14% reduction in transformer winding losses.