The EU Green Deal, beginning in 2019, promoted a roadmap for operating the transition to a sustainable EU economy by turning climate issues and environmental challenges into opportunities in all policy areas and making the transition fair and inclusive for all. Focusing on the built environment, the voluntary adoption of rating systems for sustainability assessment is growing, with an increasing market value, and is perceived as a social responsibility both by public administration and by private companies. This paper proposes a framework for shifting from a static sustainability assessment to a digital twin (DT)-based and Internet of Things (IoT)-enabled dynamic approach. This new approach allows for a real-time evaluation and control of a wide range of sustainability criteria with a user-centered point of view. A pilot building, namely, the eLUX lab cognitive building in the University of Brescia, was used to test the framework with some sample applications. The educational building accommodates the daily activities of the engineering students by constantly interacting with the sensorized asset monitoring indoor comfort and air quality conditions as well as the energy behavior of the building in order to optimize the trade-off with renewable energy production. The framework is the cornerstone of a methodology exploiting the digital twin approach to support the decision processes related to sustainability through the whole building’s life cycle.

The LoRaWAN technology, an example of Low Power Wide Area Network, is considered a possible IoT-derived solution for realizing private cellular (single-hop) communications in the industrial domain. However, despite LoRaWAN promises long range and dense environments with many obstacles (as the industrial ones), it may suffer from coverage issue. Additionally, the inverse relationship between data rates and range may be unacceptable for many industrial applications. In this paper, an innovative LoRaWAN range extender (based on an enhanced LoRaWAN node) is described, and its integration in the infrastructure of IIoT-enabled industrial wireless networks is presented. A frame relay strategy is suggested, thus avoiding to trade-off the highest data rates against an increased sensitivity. The feasibility of the solution is formally verified and the features of the realized proof-of-concept prototype, based on commercially available hardware, are discussed. The experimental results, obtained with a purposely designed test bench, show the effectiveness of the proposed approach. In particular, the range extender is transparent for legacy LoRaWAN networks as confirmed by correct relaying of uplink and downlink for different types of LoRaWAN message.

The IEC 61850 standard allows for a structured grid automation system where critical tasks like grid protections, renewable energy sources management, synchronized measurements, and monitoring applications share the communication network. So far, the use of IEC 61850 has been mainly limited to the primary substations, but more interesting could be the coordinated actions between primary and secondary substations in order to quickly react to faults and to reduce service downtimes for final customers. Unfortunately, the communication networks between primary and secondary substations are today only partially deployed. Considering this context, the broadband power line over medium voltage grid (MV-BPL) could be a suitable solution for closing the communication gaps between substations that use IEC 61850. The main objective of this paper is to present the outcomes of the first phase of a project whose final goal is the implementation in real grids of distribution grid automation based on IEC 61850. A new and comprehensive set of experiments on a real (and in service) medium voltage grid in Italy has been designed and carried out. The practicability of IEC 61850 communication over the distribution grid is assessed comparing the time characteristics of the MV-BPL against the transfer time classes of the IEC 61850, determining which IEC 61850 services may be transported over MV-BPL. The experimental long-term analysis highlights that more than 90% of the service requests are transferred on the network with a round-trip time lower than 40 ms even in the case of four hops, a time which is compatible with the IEC 61850 fast automatic interactions on MV grid.

The International Electrotechnical Commission (IEC) 61850 standard describes the communication inside the substation automation system (SAS) setting the base for new interoperating devices that share information using the Ethernet network infrastructure. More recently, the request of time synchronization among SAS components for the timestamping of critical events or synchrophasor measurement has generated a very high interest in the IEC 61850 working group for distributed synchronization protocols like IEEE 1588. This paper analyzes the current situation, matching different implementations of the IEEE 1588, and their respective accuracy, with the requirements of typical SAS applications: from the millisecond synchronization accuracy required by fault recorder application to the microsecond required by the sampled values (SV). The main focus of this paper is on the integration of IEEE 1588 with real already existing systems, and the goal is the performance comparison of different architectures. For these reasons, experimental tests have been carried out using a real SAS network infrastructure [redundant gigabit optical fiber Ethernet network managed using rapid spanning tree protocol (RSTP)]. The results show that, under ideal conditions, the IEEE 1588 protocol can achieve synchronization accuracy slightly worse (80 ns) than legacy IRIG-B systems (15 ns). However, IEEE 1588 makes possible a great cabling reduction and a simplified maintenance when synchronization is directly transferred on the SAS system bus. On the other hand, experiments highlight that nodes connected through a legacy RSTP infrastructure, which does not support IEEE 1588 messages, can lose the time synchronization in the case of network traffic or reconfiguration of the network. Therefore, the integration of IEEE 1588 over existing IEC 61850 station bus is basically a tradeoff between installation costs and performance since it requires the replacement of already installed Ethernet infrastructure. In the last part, this paper analyses the challenges for the next SAS generation that has to combine on the same plants the high accuracy IEEE 1588 implementation with high-availability protocols based on IEC 62439. Since the lifetime of an SAS is more than ten years and the adoption of these technologies takes several years, some solutions that introduce synchronization and high-availability protocols guaranteeing compatibility with existing technologies have been analyzed, too. For instance, an adaptation block that (when attached to a high-availability network) reconstructs the interface signals (e.g., synchronization signals) required by traditional bay has been proposed.

The Industrial Internet of Things (IIoT) is becoming a reality thanks to Industry 4.0, which requires the Internet connection of as many industrial devices as possible. The sharing and storing of a huge amount of data in the Cloud allows the implementation of new analysis algorithms and the delivery of new “services” with added value. From an economical point of view, several factors can decide the success of Industry 4.0 new services but, among others, the “short latency” can be one of the most interesting, especially in the industrial market that is used to the “real-time” concept. For these reasons, this work proposes an experimental methodology to investigate the impact of quality of service parameters on the communication delay from the production line to the Cloud and vice versa, when gateways with OPC UA (Open Platform Communications Unified Architecture) are used for accessing data directly in the production line. In this work, the feasibility of the proposed test methodology has been demonstrated by means of a use case with a Siemens S7 1500 controller exchanging data with the IBM Bluemix platform. The experimental results show that, thanks to the proposed method, the solutions based on OPC UA for the implementation of industrial IoT gateways can be easily evaluated, compared and optimized. For instance, during the 14-day observation period of the considered use case, the great impact on performance of the Quality of Service parameters emerged. Indeed, the average communication delay from the production line to the Cloud may vary from less than 90 ms to about 300 ms.