Rising and falling edge compensation based faster control strategy for hybrid energy storage system in PV microgrid

In microgrids, hybrid energy storage system (HESS), which consists of batteries and supercapacitors (SC), is used to maintain the power balance between the intermittent renewable energy source (RES) and the changing load demands. A sudden large change in the RES generation or the load demand might result in long rise/fall-time and large over/undershoot, causing high dynamic error in output voltage. In this paper, the current reference of HESS generated by PI controllers is translated to a positive falling signal, which can be compensated by an adaptive compensation related to the dynamic voltage error. The proposed control strategy significantly reduces the rise and settling-times, making a faster response, with reduced voltage fluctuation. Simulation results substantiate the effectiveness of the proposed method, which are further validated using a realistic hardware test setup.