A Frequency control using multiple BESS in islanded Microgrid In this paper, we proposed frequency control in islanded microgrid using a coordinated control for multiple Battery Energy Storage System (BESS) considering stateofcharge (SOC) operating. BESSs are often proposed to support the frequency control in microgrid. Because BESSs can provide instantaneous power supply, it is very helpful for the power system to solve the power demand problem in real time. However, the most important things are operating within the proper SOC range. If the operation point is not allowed within the proper SOC range, reduce to BESS life and efficiency. if the power supply demand problem is solved alone through BESS, it will be outside the proper SOC range. So, we proposed the coordinated control diesel generator and BESSs considering SOC to maintain the supplydemand in microgrid. We using the MatlabSimulink modeling and simulation analysis were performed.

Active and Frequency Control Strategy of Improved Droop Control in Islanded Microgrid The traditional droop control will reduce the frequency of the system, and will seriously affect the power quality in an independent microgrid consisting of a variety of distributed power sources. However, if the frequency recovery time is too long, the frequency does not return to the power frequency and will drop seriously and deviate from the rated value when the next load disturbance occurs. In order to solve these problems, this paper proposes a fuzzy PI active and frequency control strategy based on the traditional droop control. The degree of frequency offset is taken as the reference amount, and its control parameters are dynamically adjusted to quickly restore the frequency to the stable value. In addition, the first function term of the power and droop coefficient is established to replace the fixed droop coefficient to prevent the frequency from crossing the boundary. Finally, the effectiveness of the proposed strategy is verified by MatlabSimulink simulation. The improved control strategy can make the system frequency stable in power frequency and improve the dynamic performance of the system.