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To address the issue of frequency stability in microgrids with limited communication resources and bandwidth, this paper proposed an event-triggered control method based on a cloud-edge collaborative architecture. Firstly, to address the limited communication resources, event-triggered detector is set up at the edge to upload state variables and update control instructions only when the frequency deviation exceeds a pre-set threshold. Secondly, a fractional-order PI–PD controller is designed at the cloud control center, which achieves higher control degrees of freedom and stronger robustness than traditional integer-order PID control schemes. Additionally, to obtain better control parameters, an optimized design method based on an improved Big Bang-Big Crunch method (BB-BC3) is proposed for the fractional-order PI–PD controller. At last, a simulation example is given to prove the validity of the proposed method. Simulation results show that compared to the integer-order PI–PD controller, the fractional-order PI–PD controller based on the BB-BC3 algorithm proposed in this paper reduces the peak value of the response curve by 5%, and shortens the setting time by 0.14 s. [ABSTRACT FROM AUTHOR]

Summary: Load frequency control (LFC) is an effective method to maintain frequency stability in power systems. With the large‐scale application of wide‐area measurement system (WAMS), impacts of unexpected physical faults and malicious cyber attacks on the frequency deviation damping performance of LFC systems cannot be ignored anymore. Different from the traditional robust‐based design methods, which assume that the operating parameters vary within a small range, physical and cyber failures may cause the significant structural or parametric changes in LFC system. Hence, a system parameter‐free active fault‐tolerant control (AFTC) strategy for LFC is proposed. First, a bank containing a series of controllers is predesigned to stabilize all the possible operation scenarios. Second, a zero trial‐and‐error selection scheme, which does not depend on prior system parameters is well‐designed to select the most matching controller. To enhance the fault‐tolerant ability in case of unmodeled faulty situations, an expansion scheme without any prior faulty information is proposed. Finally, simulation results of a three‐area‐interconnected power system show that our proposed method can ensure the smooth transition of LFC system under physical/cyber failures, thereby the reliability of power grid operation can be enhanced. [ABSTRACT FROM AUTHOR]