School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China

Considering the influence of random data transmission packet loss on control precision and stability of microgrids when the networked control strategy of conventional droop control scheme is adopted, a method of networked control strategy of islanded microgrid based on distributed secondary control is proposed. The primary control part is used to achieve the load distribution, and the distributed secondary control part is used in the voltage and frequency restoration to improve the accuracy of load distribution and maintain the stability of the islanded microgrid. An improved distributed Kalman filter is proposed to estimate the output states of voltage and frequency in microgrid, which can effectively avoid the influence of random data packet loss on system stability. The proposed control strategy can realize the global optimal control based on quadratic performance index, and it is robust to the smaller data packet loss rate. Simulation results show that the proposed control method is effective and feasible.