A Fully Distributed Privacy-Preserving Energy Management System for Networked Microgrid Cluster Based on Homomorphic Encryption

The networked microgrid cluster (NMGC) integrating multiple heterogeneous microgrids is an effective way to improve the renewable energy utilization. However, the centralized scheduling scheme may be less secure and suffer from privacy concerns. In this paper, we present a fully distributed privacy-preserving energy management framework for secure and fair energy sharing within NMGC. To this end, firstly, a robust energy management model based on generalized Nash bargaining is formulated for proactive energy sharing and fair benefit allocation among microgrids. Then, a fully distributed optimization algorithm combining the alternating direction method of multipliers (ADMM) algorithm and distributed consensus protocol is designed for the formulated energy management model. It only depends on flexible peer-to-peer communication without needing any third-party coordinators, potentially preventing a single-point failure. Furthermore, a privacy preservation communication scheme based on homomorphic encryption is designed for the developed distributed optimization algorithm. With the proposed privacy preservation scheme, that is, by using ciphertext instead of plaintext throughout the entire communication and computation process, the privacy of each microgrid can be prevented from being leaked to malicious adversaries and eavesdroppers. Finally, the effectiveness and superiorities of the developed distributed energy sharing mechanism are verified via numerical case studies.