Communication & Knowledge: the new IT revolution

Smart Grids and Standards

Electrical networks are complex systems. They are even termed as "systems of systems", thus indicating a particularly high level of complexity. To allow such systems to function, many standards are needed. The focus of Smart Grid is on "clever" communication: the first target is interoperability, the capacity of a product or system, whose interfaces are fully known, to work with other (existing or future) products or systems.

Indeed, interworking of two parts of a system can only be achieved if the participants (mainly systems or subsystems) are fully informed about the terms of interoperability: the nature of the exchanged flows, the interface description, etc.

This will be enabled by the definition and implementation of network architectures where different stakeholders are able to interact in cooperation - rather than through the centralised control of a hierarchical network - to provide new applications.

A organisational framework for Smart Grid standardisation

In the case of an electrical network, interworking involves both a physical exchange (electricity flow) and an exchange of communications (to allow the coordination and control). The standards must govern both.

In Europe, the European Commission established a Smart Grid Task Force in 2009 that addressed standardisation in the European context. One must remember that only three European organisations are empowered to produce European Standards: CEN, CENELEC and ETSI. In late 2010, the Commission issued a "European Mandate" (M/490) defining the objectives for Smart Grids standardisation: the three European organisations have gathered in the Smart Grid Coordination Group (SG-CG) to implement them.

The approach taken in Europe and the USA is to coordinate the technical work and to promote the largest initiative of the industry. Thus, the SG-CG is not intended to produce standards, but to identify those that are already in force and those that are missing ("standards gaps") and need to be developed in the Technical Committees (e.g. within IEC, ETSI, etc.).

The Smart Grid Architecture Model

Modelling actors and roles is an essential pre-requisite in Smart Grids. Indeed, the time is past when most of the interactions between actors (e.g. EDF, E-ON) were made in the context of similar roles (e.g. energy distributor). With the Smart Grid, more complex interactions must be allowed between actors playing different roles (e.g. energy trader and distributor) with more complex market organisations and regulations.

On top of the Actor and Role Model, another key element of this approach is the SGAM (Smart Grid Architecture Model), a three-dimensional representation of the space of Smart Grids, summarised in the figure below, which describes the two main aspects of the area of Smart Grids.
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The "Smart Grid Plane", where the actual implementations of Smart Grid will work, encompasses two dimensions:
  • The "Domains" representing the different components of the physical part of the processing power: Generation, Transmission, Distribution, Distributed Resources, Customer Premises (individuals or companies). Part of the novelty of the model is that it takes into account, under the term "distributed resources", the energy produced locally, including renewable energy, which was an essential prerequisite in Europe.
  • The "Zones" that represent the hierarchical levels of the power management system (its computer part) as they move away from the electrical process: Field, Station, Network Management, Enterprise, and Market. An important aspect of the model is the inclusion of the "Market" level that allows to neutrally describe different "business models" without mandating any of them.

The Interoperability layers describe a Smart Grid system at higher and higher levels of abstraction above the physical layer (the Smart Grid plane): Component, Communication, Information, Function, and Business. These layers allow the analysis of a use case with different approaches according to the needs: for example, the analysis a business model will be done at "Market" level; analysing communication protocols will be at the "Communication" level.

The SGAM model was defined for the standardisation community: on a given case study, it allows the identification – at all level(s) desired for interoperability – of existing or missing standards. But other actors can use it: researchers analyzing a new element of system, engineers considering the implementation of a product, etc.

More can be found on our paper, here.