Distributed Secondary Frequency Control of Islanded Microgrid Considering Power Constraints

In islanded microgrids, secondary frequency control is often employed to compensate for frequency deviations caused by droop control, thereby enhancing the frequency security of the system. However, distributed generators (DGs) such as renewable energy sources and energy storage systems in microgrids have inherent power output constraints. Ignoring these constraints may lead to the system frequency failing to meet expectations or even exceeding safety limits, posing security risks. To address this issue, this paper proposes a distributed secondary frequency control strategy that considers power constraints. First, a model of the islanded microgrid system is established. Second, a distributed secondary frequency controller incorporating power constraints is designed, and the stability of the proposed control strategy is analyzed using Lyapunov theory. Finally, a simulation model is established in Simulink to verify the feasibility of the proposed control strategy through simulation.