Secondary frequency control for multimicrogrid system
LIN Yanyan1, XIAO Hongfei1, CHEN Leilei2, WU Chenxi1, QIAN Hao1
(1.Institute of Automation, Hangzhou Dianzi University, Hangzhou 310018, China; 2.Beijing T&D Power Research Co., Ltd., Hangzhou Branch, Hangzhou 310007, China)

Abstract: Aiming at the problem of frequency regulation for multimicrogrid system, power balance, secondary frequency regulation and tieline power control were studied. A novel secondary frequency control strategy was proposed. A microgrid central controller（MGCC） was designed to undertake the task of frequency regulation. According to deviations of system frequency and tieline power, the expected total power was calculated, which was allocated to the DGs taking part in the secondary frequency regulation. The DGs adjust their outputs to balance the system power vacancy. Simulation studies were performed on a doublemicrogrid system. Load fluctuations in one microgrid and in both microgrids were carried out respectively on the test system. The results indicate that the proposed control strategy can help to recover the tieline power to the planned value and maintain the frequency stable.
Key words: multimicrogrid system; secondary frequency regulation; microgrid central controller; tieline; microgrid control error