Comparison study of the controllers for grid connected battery system

This paper performs a comparison study on the performance of operation of a battery connected grid system with bi-directional grid-connected inverter and conventional PQ controller in steady state conditions. The deployment of a 1 MWh battery energy storage system (BESS) at Reese Technology Center (RTC) in Lubbock, Texas is described. The battery energy storage device was installed to further understand the interaction and performance of the battery within the power grid with the existing wind turbines at RTC as well as renewable energy sources and grid loads. The paper shows the simulation results obtained from PSCAD with the design of the different controllers. Compared with conventional PQ controllers, the bi-directional converter controllers greatly enhance the grid-connected converter´s performance in the aspects of reduced power oscillations and increased operating stability.