Control Method of Self-Frequency Recovery and Active Power Sharing for an Isolated Microgrid Based on VSGs

• Published in: Journal of electrical engineering & technology 2019, 14(1), , pp.157-167
• Main Authors: Xing, Pengxiang, Ma, Fan, Tian, Chunzheng, Xu, Changqing, Wang, Lili
• Format: Article
• Language: English
• Subjects: Electrical Engineering; Electrical Machines and Networks; Electronics and Microelectronics; Engineering; Instrumentation; Original Article; Power Electronics; 전기공학
• ISSN: 1975-0102; 2093-7423
• DOI: 10.1007/s42835-018-00043-3

The concept of virtual synchronous generator (VSG) is emerging as an attractive solution for renewable energies to enhance the microgrid inertia and damping property by emulating the essential behaviors of conventional synchronous generators. However, in the isolated microgrid based on VSGs, there will be a frequency deviation when the power demand varies because of the droop characteristic of the VSG in active power–frequency regulation. In this paper, a control method for VSGs to implement self-frequency recovery and active power sharing in isolated microgrid is proposed. With this method, the VSGs regulate their power baseline values over multiple iterations through local-feedback of the frequency deviation until the microgrid frequency restores to normal value, and simultaneously share the power demand variation according to the ratio of their power baseline values. Compared to the previous studies, the proposed method can eliminate the output power and frequency oscillations in secondary control, and additionally, reduce the dependence of the microgrid on communication system, which is beneficial to enhance the robustness of the microgrid operation. Simulation results proved the proposed method to be effective.