A novel secondary frequency control strategy for islanded microgrid based on identification model

Secondary frequency regulation control strategy plays a key role in maintaining the stability of frequency and improving power quality, especially in droop-controlled microgrid system. However, due to the confidentiality of manufacturers, the internal structure of microgrid cannot be obtained, thus the conventional second frequency regulation strategy based on mechanism modeling may be unavailable. To solve these problems, this paper presents an online identification method for droop-controlled microgrid system, which can also be used for online optimization of secondary frequency regulation controller. The whole frequency regulation process is described in detail, and simulation results are carried out to show the validity of the proposed strategy.