ETHERNET-BASED MONITORING SYSTEMS FOR RENEWABLE ENERGY-HYDROGEN MICROGRIDS Antonio José Calderón Godoy, Isaías González Pérez, José María Portalo Calero, Manuel Calderón Godoy Escuela de Ingenierías Industriales, Universidad de Extremadura, {ajcalde, igonzp, calgodoy}@unex.es Abstract The digitization of power systems has given birth to the rise of challenging scenarios like Smart Grids and Smart Microgrids. These infrastructures are mainly based in decentralized energy generation as well as in the intelligent management of the energy flows and data communications. For their successful implementation, a communication network is imposed for the proper data transmission between the vast amount of sensors, controllers and supervisory nodes involved. Ethernet-based networks have become the prevalent means for communications in office environments and are being increasingly applied also for industrial facilities. Consequently, Smart Grids and Smart Microgrids are also being equipped with Ethernet communication. This paper presents an Ethernet- based monitoring system architecture where monitoring software, proprietary automation hardware and open-source equipment share data over an Ethernet network. A set of experimental facilities are reported in order to prove the validity of the proposal. Keywords: Renewable energy, microgrid, Ethernet, automation, monitoring, communication network, IoT. 1 INTRODUCTION The digitization of power systems involves the massive introduction of sensing and automation technologies causing the evolution towards the so- called Smart Grids and Smart Microgrids. The future energetic scenario is envisioned to be supported by these intelligent grids with enhanced capabilities of decentralized generation, optimized efficiency and higher introduction of renewable energy sources. Microgrids integrate both physical elements in the power grid and cyber elements (sensor networks, communication networks, and computation core) to make the power grid operation effective [21]. Apart from the energy flows, information flows characterize these grids [22]. Consequently, proper information management and transmission networks are required between the vast amount of sensors, controllers and supervisory nodes involved. Indeed, the implementation of distributed monitoring and control systems is signalled as one of the main challenges in the Smart Grid scenario [4]. In this sense, Ethernet is a widely applied standard for networked communications. Namely, Ethernet corresponds to the IEEE standard 802.3 [15]. Within the Open Systems Interconnection (OSI) model, Ethernet operates in the two lower layers, the physical level (layer 1) and the link level (layer 2). The Transmission Control Protocol/Internet Protocol (TCP/IP) is commonly deployed for Ethernet-based communications. Such a combination provides important building blocks to achieve technical interoperability between disparate digital systems [19]. Ethernet provides high bandwidth, scalability and modular configuration with inexpensive expenditures. Moreover, in the context of R&D projects, the application of Ethernet communication fosters an enhanced management of interoperability and flexibility. Both benefits acquire special relevance when a variety of heterogeneous equipment must be integrated and/or modified. In fact, Ethernet is becoming a de facto standard in office, enterprise or business systems and modern Cyber-Physical Systems (CPS) [19]. Indeed, the undeniable prevalence of Ethernet networks contributes to the trend of industrial networks towards such communication means. Both proprietary and open communication protocols widely used in industrial environment have released specifications for Ethernet. Fieldbuses like Modbus TCP, PROcess FIeld NETwork (PROFINET), Ethernet for Control Automation (EtherCAT) or CC- Link IE are examples of such trend. Another remarkable aspect concerning industrial control equipment is the application of Programmable Logic Controllers (PLC) to automate renewable energy facilities and microgrids in literature [3, 8, 9, 16]. Modern PLC include Ethernet XLII Jornadas de Autom´atica Control Inteligente 190 https://doi.org/10.17979/spudc.9788497498043.190