An improved frequency control method for microgrid in islanded operation

Some existing microgrid frequency control methods imitated traditional power system primary frequency regulation and secondary frequency regulation. Advantages and disadvantages of this imitation are analyzed and an improved frequency error integral regulation method for islanded microgrid operation is proposed in this paper. The proposed control strategy can implement no-error adjustment of microgrid frequency. In order to overcome the drawbacks of low inertia of microgrid, motion equation of rotor of synchronous generator (SG) is supplemented to the proposed frequency control strategy, which can make frequency to reach a new steady state relatively slowly while loads fluctuate rapidly. Therefore, stability of frequency in microgrid is thus improved. Typical operation states of microgrid operated in islanded mode, such as load random fluctuation, are simulated based on MATLAB/Simulink. Simulation studies prove the effectiveness of the proposed frequency control strategy.