Battery Currents Limitation in Passivity Based Controlled Battery/Supercapacitor Hybrid Energy Storage System

In stand-alone power supply systems, due to fluctuations of electric energy generation and consumption, special devices are used for energy storage, most often batteries. In order to remove stress from batteries during sudden load change, it is advisable to use hybrid energy storage system (HESS), by adding a supercapacitor module to the battery. In this work, stand-alone power supply system with battery/supercapacitor HESS of active configuration are investigated in two modes with different structures – at the low load and at the high one. In the latter battery current should be limited due to improve the battery lifetime. Both HESS structures are represented as port-controlled Hamiltonian systems, and the synthesis of control systems is carried out using the IDA-PBC method. Given the nonlinearity of the system and its propensity to oscillations, the transition to the battery current limitation is accomplished by implementing the sliding mode of switching of the designed controllers. The conducted simulation studies in the Matlab/Simulink environment showed the workability and effectiveness of the proposed solution.