OPC UA-based three-layer architecture for aggregated microgrids integrating edge cloud computing and IEC 62264

This paper presents a three-layer architecture based on Open Platform Communications Unified Architecture (OPC UA) to address interoperability challenges in aggregated microgrid systems, including protocol heterogeneity and latency mismatches. Designed to meet the latency requirements of two key energy management strategies — high-step (hourly BESS scheduling) and low-step (real-time BESS adjustments) — the architecture segments communication into the Microgrid Aggregation Layer, Communication Platform Layer, and Distributed Microgrid Layer. The proposed architecture achieves seamless and scalable data exchange while ensuring compatibility with heterogeneous devices and supporting flexible operations by leveraging the OPC UA platform, Fieldbus protocols, edge cloud computing, and IEC 62264 standards. Compared to IEC 61850, OPC UA offers broader interoperability, dynamic semantic modeling, seamless OT/IT integration, and robust TLS/AES256-based security, making it well-suited for secure cloud-integrated microgrids. Additionally, OPC UA-based communication operates through dynamic information models. These models enable flexible and adaptive structuring of device data in the microgrid ecosystem. This paper also defines Cloud and Microgrid Component Information Models, specifically designed for microgrid environments. These dynamic models enable selective data updates and hierarchical structuring of information, reducing unnecessary network traffic and improving responsiveness across the architecture. Validation on a real-world testbed demonstrates up to 17.86-fold latency reduction and compliance with Industry 4.0 benchmarks, highlighting the effectiveness of the architecture in enabling scalable, real-time microgrid management and establishing a robust foundation for practical energy systems.