Model-Based Control Design for a Battery/Ultracapacitor DC-DC Converter System

For battery and ultracapacitor hybrid energy storage systems, the design and control of the DC-DC converter is an important stage of the system design process. The design approach for a model-based controller for a half-bridge DC-DC converter is presented with experimental results from a scaled test configuration. The contribution of this paper lies in presenting a well-behaved discrete-time system model, a controller tuning methodology, and an effective technique to address the nonlinear system response caused by discontinuous conduction. The results show that the controller bandwidth and command tracking that is achieved with the proposed techniques meet application requirements, and that reduced design effort is required for the presented tuning methodology, combined with helpful physical insights. The presented approach can also be generalized to other DC-DC converter systems.