Frequency-based energy management of stand-alone systems: Design of the control parameters for high versatility

Frequency-based energy management strategies have been proposed for stand-alone systems with either centralized or distributed energy storage. This paper proposes a methodology for the design of the control parameters which ensures stability in both type of systems. As a result, the inverter manufacturer can implement one sole strategy, regardless of whether the expected stand-alone system is centralized or distributed. In addition, the battery inverter becomes more versatile since it can be used alone or in parallel with other battery inverters. Simulation results corroborate the theoretical analysis and demonstrate that energy management is carried out with no need of communication cables for a system with 1, 2 or 3 battery inverters with the same firmware.