An advantageous grid integration method and control strategy for renewable energy sources and energy storage systems

Abstract:
Utilization of renewable energy sources (RES) is increasing. But there are several problems related to their grid integration like voltage and overload issues, a more and more complex system operation and no benefits for the power system. To cope with these challenges, a new integration method was proposed in this paper called Smart Power Plant (SPP). The approach is simple and reliable, beneficial for the power system and capable of replacing conventional power plants. Instead of coupling RES individually to the nearest grid connection point, RES are clustered in a RES-grid. By adding different energy storage systems (ESS), renewable power generation becomes schedulable and limited to well-known centralized coupling points. The components within the RES-grid are operated by droop controllers. Thus, the SPP does not require extensive communication networks. Simulation results demonstrated, that dynamically adapted droops ensure an optimal power sharing and operation of the different ESS. Along with the reduced number of RES coupling points, the operation of the power system remains simple and reliable.