Modeling and control design for power systems driven by battery/supercapacitor hybrid energy storage devices

This paper addresses several important problems in a typical power system driven by battery/supercapacitor hybrid energy storage devices. The currents in the battery and the supercapacitor are actively controlled by two bidirectional buck-boost converters. Detailed investigation is conducted on deriving two state-space averaged models for the whole interconnected system. The control objective is to track the references of two variables. The control design problem is converted into a numerically efficient optimization problem with linear matrix inequality (LMI) constraints. When the optimization algorithm is applied to an experimental system, the resulting optimal control law is very close to a simple integrator control (with two inputs and two outputs). The simple integrator control is applied to the system in both simulation and experiment. The results confirm the effectiveness of the modeling and control design methods.