Fully Distributed Event-Triggered Security Control for DC Microgrids Subject to DoS Attacks

As the application of distributed DC microgrids becomes more and more widespread, their voltage restoration and current sharing that cannot be guaranteed simultaneously due to droop control have received a lot of attention. In this paper, we propose a new adaptive safety control strategy with an event-triggering mechanism to reduce the communication burden. The current sharing of the distributed generation units is guaranteed while bus voltage deviations are eliminated. The control objectives are well achieved even under DoS attacks. Moreover, the controller and the triggering mechanism are designed to be scalable without the bus voltage sampling and any global information. The stability of the control system is proved by the Lyapunov theory, and Zeno behavior is also strictly ruled out. Finally, the simulation results illustrate the validity of the proposed approach.

I. Introduction

Amicrogrid (MG) can integrate many distributed energy resources (DERs) to meet different power requirements as a small controllable power system. It has a low investment cost and can be continuously powered in a stand-alone mode. With the increasing demand for electricity in modern life and the improvement of power generation technology, it is of great importance in modern power grid due to its high efficiency, flexibility and scalability. MGs are categorized into AC, DC and hybrid MGs depending on the type of power supply connections [1]. Although AC microgrids are widely used today, they need to be designed with the consideration of reactive power flow and phase fluctuation [2], [3], [4], [5]. Hybrid MGs can combine AC and DC loads, but the controllers are more complex and not easy to be implemented. DC MGs are gaining more and more attention due to the advantages of low conversion losses, and no need to focus on frequency synchronization and reactive power compensation.