Smart Grid Telecommunications. Ramon Ferrús

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      There are multiple DER elements, including DG but also Energy Storage (ES), and not forgetting Electric Vehicles (EVs), that play a role for the system (positive, as “batteries on wheels”; challenging, as “moving loads”) further than their direct environmental impact (reduction in fossil energy sources consumption).

      DG includes wind power, solar power, geothermal power, biomass, and fuel cells. They can be manageable or unmanageable from the grid perspective, depending on several factors such as their installed capacity, the availability of the energy they produce, and the connectivity and intelligence of their ancillary elements for grid integration. Notwithstanding, when these elements are available and connected at end‐user premises of small producers and communities, the consumer has the dual role of consumer and producer (i.e., a prosumer). However, the overall traditional concept of the energy power system protection and control needs to adapt to this new reality.

      EVs, on their side, have a very interesting role to play. EVs contribute to the overall energy waste reduction, system efficiency, and fossil fuels and emission reduction and are seen as moving batteries to help the system. This can be done by means of the storage of certain types of energy produced at times where the consumption cannot take advantage of them [40] and be used to charge EVs and have it delivered when and where it is needed.

      1.5.2 Grid Control Challenges

      Within the Transmission segment, challenges are those inherent to its role in the system. Despite the evolution of the electric power system technologies, Transmission has not been affected by technical disruptions that impose a new reinvention of its nature. However, their traditional functions can be pretty much enhanced.

      The need to keep energy loss at a minimum justifies the need to understand and control the different power line parameters involved in ampacity (i.e., maximum value of electric current – Amperes) calculations. Grid stability is another concept of great importance, as the connection of bulk‐generation at different parts of the network can cause instability if the voltage phase difference between the power signals is too different at the two ends of the line. Last but not least, harmonics of the fundamental frequency (50 or 60 Hz) have to be controlled, as they would be propagated along the grid, impacting overall quality of the electricity wave.

      There are other needs related with the physical aspects of the cables, leading to keep the infrastructure available and extending its useful life [41]. There is a growing need to easily detect the origin of faults in the power lines and be able to identify and communicate its exact location. These needs can be supported with modern telecommunications‐related technology. These technologies can also help to control strain in the cables when they are being laid out, specifically in cables under special conditions (e.g., submarine routes).

      Distribution grid challenges are the ones that have been driving the evolution of the Smart Grid concept in the network control side. The paradigm of a static unidirectional network delivering electricity from the core to the edge has changed into an entangled mix of new technologies and assets, with varied properties, that needs to be organized. The new idea of a “platform” [42], rather than a “grid” that can serve the different Distribution grid stakeholders, has become popular due to its use in some major initiatives.

      Automation tries to drive the grid toward becoming a self‐healing entity. Automation in utilities consists of Substation Automation (SA) and Distribution Automation (DA). Automation process started at substation level, mainly PSs (hence SA), and moved out toward the edge (hence DA), increasing its ambition to reach every corner of the grid with that kind of automatic signals driving electricity through the most appropriate routes (like information is routed in telecommunications networks, differences aside). The aid of ICTs and telecommunications in grid automation is highlighted in [43] with the term ADA (Advanced Distribution Automation). The ultimate objective of the self‐healing grid is to improve the service availability introducing efficiencies in the grid operation (less manual and field interventions).

      The appearance of DER alters the traditional equilibrium of things in the Distribution grid. E.g., DG and EVs come with some caveats that change the landscape of traditional grid operation. On the more general side, operational procedures need to be modified as they can no longer assume that energy flow is not unidirectional (restoration manoeuvers may need power to be completely for the safety of people and assets). On the other, a greater visibility and control of the elements of the grid, including those of the new technologies close or in the Consumption Points, to enable the operational procedures.

      Now the Smart Grid in the Distribution segment needs to be seen as the superposition of the grid with the new grid technologies, and a telecommunications network providing connectivity to any corner of the grid to measure, control, and remotely operate the different IEDs (Intelligent Electronic Devices) attached to the grid assets [35]. A different proportion of central and distributed intelligence will use this connectivity to run algorithms able to make autonomous decisions and perform sophisticated actions that will be monitored from UCCs.

1.6 Challenges of Telecommunications for Smart Grids

      Telecommunication networks, systems, and the services they provide are defined to fulfill a set of technical requirements within the state‐of‐the‐art solutions and the affordable economic conditions.

      Thus, not any telecommunications solution can fulfill the need of any service. However, from a pragmatic perspective, some needs and/or some industries may trim their requirements to the capabilities of existing telecommunications solutions.

      From a practical Smart Grid implementation perspective, one of the main decisions when selecting telecommunication solutions is the option of deploying private telecommunication networks, as an alternative to using commercial telecommunication services from TSPs. It is often not a question or selecting one or the other, but how to select the best combination of both, leveraging the full control that private networks offer, with the use of TSP services that may be already available in third‐party deployed networks (TSPs'). In both cases, but probably more relevant when the services are provided by TSPs, there are two important aspects that need to be taken into account. The first one is the national regulation of the conditions under which any telecommunication solution is licensed in a given territory; the second, pretty much affected by the first one, is the network design and its implementation on field, together with the operation and maintenance aspects.

      Thus, the service adequacy of a telecommunications solution needs to be evaluated considering the integration of several aspects, at least, the solution conception based on the requirements to be fulfilled, and its practical implementation within the constraints of network design decisions, regulation and business plans. As a consequence, the assessment of how the different Telecommunication solutions fit Smart Grid requirements must evaluate many different alternatives under a non‐evident set of considerations.

      1.6.1 Telecommunication Solutions for Smart Grids

      Smart Grid infrastructure refresh cycles are much slower than telecommunication's. In general terms, we could say that the useful lifetime of a grid technology is always higher than any telecommunication solution that could be used in it, with factors ranging from 1.2 to 2.5 (see examples in [44]). If a telecommunications solution is to be found for a specific Smart Grid need, it is not just the requirements, or the basic technology supporting it that deserves attention, but the way in which the telecommunication solutions are to be sustained over time and how to better approach this.

      The consideration clearly exceeds technical aspects, but probably economic aspects as well, as the feasibility of modifying infrastructure СКАЧАТЬ