"LINK" Model Envisions Paradigm Shift for GridBy Engineering360 News Desk | March 25, 2016
Power engineer Albana Ilo, from the Institute for Energy Systems and Electrical Drives, at TU Wien, has rethought the basic power grid concept and developed a new smart-grid paradigm aimed at making it adaptable for the future—one marked by decentralized electricity generation, alternative energy providers and integration of generation and storage all the way to the level of individual households.
"LINK" re-organizes the management of networks, electricity generation, energy storage facilities and consumers by dividing the whole system into clearly defined units ("links"), each with its own control system and clearly defined interfaces to its adjacent unit. This, she says, should result in a simpler and more automated electricity industry, while providing greater stability and solving data protection issues.
"For years, we have been discussing new concepts such as virtual power plants or 'microgrids,'" notes Ilo. Virtual power plants combine a large number of small, decentralized power generators. While this allows them to compete in the market, technical problems remain, as they cannot be controlled as easily as a physical power plant, and large quantities of data have to be constantly exchanged in order to keep the system working.
The electricity market, the management of the networks and the actual physical aspects don't necessarily fit together, Ilo says. Physically, the power grid is divided into a high-, medium- and a low-voltage grid. There are also power stations, storage and consumers to add to the mix. Ilo thinks that the management of the power grids should be divided along these same lines.
The individual elements in her LINK paradigm fit together like links in a chain that can be combined and connected as requirements dictate. In Ilo's concept, a high-voltage grid—Austria's, for example—would be managed separately, based on a physical model. Using clearly defined interfaces, it communicates with neighboring high-voltage grids and subordinate medium-voltage grids.
This system of linked elements continues right down to the household level. Each "link" receives input from its neighboring elements and then decides which actions need to be taken. This means it will not be necessary to send large volumes of data to a central coordinating center, Ilo says.
"With regard to data protection, it's a huge advantage," emphasizes Ilo. "Nobody would want utility companies to be able to collect data about individual devices being switched on and off in their own house. In our LINK paradigm, this is no longer necessary." Each link shares only a small set of absolutely necessary electrical data with the neighboring units, and the rest of the information is used only locally. The danger of cyber-attacks from outside is thereby reduced drastically.
LINK leads to a new kind of power grid operation that is consistent with physical aspects of the grid. "Today, electricity can be sold from the North Sea to Italy. Physically, however, the electricity might flow via the Polish grid, which can become overloaded—although the country is not even involved in the deal," says Ilo.
In a LINK system, this would be easy to manage. The individual high-voltage LINKs would automatically adjust all parameters so that such transactions could be carried out smoothly. The risk of major blackouts would be eliminated, she says.
Instead of making further small adjustments and implementing emergency solutions—complicating an already outdated power grid system—LINK could be a clean, fresh start across the whole system, according to Ilo. A resilient, self-regulating operating system would also minimize the need to expand the network. "The European power grids still have capacities," she says. "We just need to make the most of this."
A small-scale pilot project in a test region in Salzburg has already shown that the concept works, and a gradual transition from the current system to the LINK paradigm should be possible. "It's not an overnight process, or even something that can be achieved in just a couple of years," says Ilo. "However, the transition to a smart power grid is possible, and if we take the move to Energiewende seriously, we should start now."