An Improved Privacy-Preserving Consensus Strategy for AC Microgrids Based on Output Mask Approach and Node Decomposition Mechanism

The technology of distributed cooperative consensushas been widely used in inverter-based microgrids. However,the traditional information interaction will lead to the problemof data disclosure. Although privacy issues have been widely researched in the tertiary control layer of microgrids, the issues of secondary control layer have not been properly addressed.To fill this gap, taking voltage restoration as the object, the privacy preserving consensus problem for secondary controllayer of nDGs is landed microgrids is considered in this paper.Output mask approach, the basic idea of which is to inserta dynamic mask to the transmitted information, is adoptedto achieve an accurate consensus rather than a pre-specified convergence accuracy level by differential private method. Afterthat, a newly state decomposition mechanism is proposed, the DG agent is decomposed into two subagents, called x(i)( alpha)and x(i)(beta).Among the agent pairs(x(i)( alpha),x(i)(beta)), choose only one subagent ofpairiarbitrarily connected to one subagent of its neighboragent pair. Furthermore, only the communication lines among theagent pairs are masked. Compared with the existing literature,the constraint on the communication topology can be firstremoved without additional computational burden. Moreover,the consensus and privacy analysis of the controlled systemare carried out. In the end, the simulation results verify theeffectiveness of the proposed privacy preserving mechanism inthe MATLAB/Simulink environment.