Modeling and simulation of SST/BES

This paper proposes Solid State Transformer incorporated with Battery Energy Storage (SST/BES) to improve the reliability of residential power supply. The proposed SST/BES is composed of a SST, a battery bank and a bidirectional dc-dc converter. The SST has the capability of power-factor correction and controls bi-directional energy flow. The battery bank is connected to the low voltage dc link in SST via the dc-dc converter. The dc-dc converter reduces the number of battery and supplies the power demanded by the residential load in the event of the voltage sags and momentary interruptions of the input voltage. Detailed modeling and control strategy of SST/BESS topology are discussed and a cooperative control is developed. The performance of proposed system is analyzed using simulations based on Matlab/Simulink. Simulation results have verified that SST/BES has very good performances, and it can not only avoid loads impacting the primary system, but also can prevent from voltage sags and momentary interruptions infecting the loads.