A wireless, decentralized and nonlinear energy management strategy using PCC frequency for islanded AC microgrids

This paper presents an islanded AC microgrid composed of multi-DGs and an energy storage system. The point of common coupling (PCC) frequency and voltage magnitude are controlled by the ESS while other DGs can export active power and reactive power independently. A nonlinear energy management control strategy is proposed by utilizing the PCC frequency as an agent for all constituent units, which avoids any communication lines among the constituent units. The operation principle of the energy management is explained. The proposed energy management is effective not only for normal operation but also for the circumstance when the battery is fully charged and DGs can supply more power than the load consumption. For the latter extreme situation, all DGs can automatically reduce their output power until the battery works in float charge state. The effectiveness of the proposed strategy is verified by simulation and experimental results.