A High Performance Communication Architecture for a Smart Micro-Grid Testbed Using Customized Edge Intelligent Devices (EIDs) with SPI and Modbus TCP/IP Communication Protocols

This paper presents a high performance 4-layer communication architecture for a smart micro-grid testbed which consists of a 2 kVA Distributed Energy Resource (DER) inverter with PV and battery channels capable of advanced grid supportive and grid forming functions in the Process layer, a Raspberry Pi computer in the Interface layer, a customized Edge Intelligent Device (EID) in the Sub-station layer, and an end-to-end solar energy optimization platform (e-SEOP) in the Supervisory layer. The Raspberry Pi serves as a communication interface which communicates with the DER inverter using Serial Peripheral Interface (SPI) communication and talks to the EID using Modbus TCP/IP protocol. This paper provides a convenient and comprehensive solution to SPI and Modbus TCP/IP communication implementation in a smart micro-grid. The challenges of coordination between communication and system control and between different communication protocols have been addressed, which leads to a boost in the communication efficiency and makes the system highly scalable, flexible and adaptive. The proposed communication architecture as well as the micro-grid test bench have been validated through hardware experiments. The results indicate a reliable and efficient communication among different layers, which facilitates large-scale status monitoring of edge devices and coordinated control of the entire system.