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As a promising method with excellent characteristics in terms of resilience and dependability, distributed methods are gradually used in the field of energy management of microgrid. However, these methods have more stringent requirements on the working conditions, which will make the system more sensitive to communication failures and cyberattacks. As a result, it is both theoretical merits and practical values to investigate the malicious effect of cyber attacks on microgrid. This paper studies the distributed economic dispatch problem (EDP) under denial-of-service (DoS) attacks for the microgrid, in which each generator can communicate with its neighbors and has the computational capability to implement local operation. Firstly, a DoS attack model is proposed, in which the DoS attacker intentionally jams the communication channel to deteriorate the performance of the microgrid. Then, the evolution mechanism of the dispatch system of the microgrid under different attack scenarios is adequately discussed. On this basis, an optimal attack strategy based on enumerating-search algorithm is presented to allocate the limited attack resources reasonably, so as to maximize the effect of DoS attacks. Finally, the validity of the theoretical studies about the attack effect under different scenarios and the effectiveness of the proposed enumerating-search-based optimal attack strategy are illustrated through the simulation examples on the IEEE 57-bus system and IEEE 39-bus system, respectively.

In this work, from the point of calcium ions in the cytosol, we extend a 𝑉𝑚-[Ca 2+ ]𝑐𝑦𝑡 model to explain the changes of action potential 𝑉𝑚 of the plasma membrane and the calcium concentration in the cytosol [Ca 2+ ]𝑐𝑦𝑡 under an alternating electric field in cells. An alternating external electric field may exert an oscillating force to each of the free electrolytes, existing on both sides of the plasma membrane. The mechanism for the alternating electric field induced-effects on 𝑉𝑚 and [Ca 2+ ]𝑐𝑦𝑡 is elucidated. The simulation results show a correlation between the changes of [Ca 2+ ]𝑐𝑦𝑡 and the alternating electric field. When the numerical ratio between the intensity 𝐸0(mV/m) and the frequency 𝜈 (Hz) of the field was about 1-2, the [Ca 2+ ]𝑐𝑦𝑡 signal is changed dramatically. The bioactive changes of [Ca 2+ ]𝑐𝑦𝑡 appear at low frequency, in the range of 0-100 Hz.