By Peter Pfisterer and Christian Dirmeier, TàƒV SàƒD AG Embedded Systems
It will be crucial to upgrade existing electricity grids into smart grids if Germany’s government is going to successfully phase out nuclear energy and replace it with renewable generating sources. Smart grids must be more decentralized, highly connected and capable of autonomous control operations, from coping with fluctuations in power supply to direct communication with energy consumers. Integrating electricity generation, distribution and consumption calls for a high degree of automation, information technology and data security.
As electricity generated from renewable sources expands, more power plants that depend on specific weather conditions are connected to the grid, including remote industrial-scale power stations such as offshore wind farms, as well as small privately owned solar power systems in conurbations. This trend is starkly different from existing grid architecture that was designed to transport electricity from central large-scale power stations to consumption areas. In Germany, electricity was not transported more than 70 km.
While constructing new lines, electricity providers also must establish control and data networks that permit complex communication. Static electricity grids must be changed to flexible infrastructure that can reciprocally control energy producers, distributors and consumers. This will require integrating electricity generators, grid nodes, grid control centers, industries, buildings, households and electric vehicles.
Complex logistics and technology
The European Union Commission recently launched an infrastructure package aimed at cutting planning times from 10 years to three years or less. The package supports expanding and upgrading energy grids with its more than 9 million euros. Challenges encountered establishing a smart grid infrastructure must not be underestimated, however. A project’s complex logistics and technology can create obstacles. Smart grids require many stakeholders, including energy suppliers, investors, industry, politicians and the public, to agree. In many cases, additional information is required to gain acceptance from industry and private households.
In addition, new components suitable for smart grid use that provide comprehensive measurement and control functions in real time must be installed. Embedded systems such as components with processors that can process signals independently play a significant role. While these systems have been used for decades in industrial plant control system automation, challenges still exist when implementing smart grid-enabled communication systems and end-to-end networking of the control systems up to the grid control center via Ethernet. This might create cyber sabotage risks in industrial and data security, including new malware such as trojans.
Possible solutions and policy
First, transparency of smart grid opportunities and risks must be ensured. Second, smart grid components must reliably fulfill standardized requirements, including interoperability, safety, security and usability. So far, know-how concerning integration of built and new systems into smart grids offers room for improvement. Systems must be interactive, operationally secure (protected from malicious attacks) and highly usable. The IEC 61850 communication standard is recognized as a global communication standard. A certificate of conformity in accordance with this standard, however, doesn’t provide a guarantee that equipment made by different manufacturers will be interoperable.
IEC 61850, nevertheless, is the smart grid backbone. It defines the principles of bidirectional data transfer between electricity producers, consumers and distributors via the Ethernet. The standardized data models and nodes allow a well-functioning overall system to be established. This system permits comprehensive data communication between the connected components, as well as largely automated utility grid management. Further advantages of a system based on the IEC 61850 standard include its modular structure and simple configuration via XML files. In addition, systems based on the IEC 61850 standard might offer interfaces with the standardized IEC 60870-5-101 or 60870-5-104 telecontrol protocols, which will gradually be replaced by IEC 61850. This facilitates grid integration of existing plants and new components.
Criteria for components
Components have some catching up to do. Most grids designed in accordance with IEC 61850 are high-voltage grids. By contrast, an insufficient number of devices in the medium- and low-voltage sectors comply with the standard. In Germany for example, the electricity grid has some 1 million substations and only one-quarter to one-third comply with the communication standard or are “enabled for communication.” Grid operators, therefore, are challenged to change the entire infrastructure into a smart grid. And, equipment manufacturers must develop and supply devices that reliably fulfill IEC 61850 standard requirements and can communicate securely with each other. Many regional projects are still highly incompatible.
Additional and impartial tests, such as realistic conformity, performance and interoperability tests, can prove the extent to which technical components, including sensors, actuators, signal generators, security devices or smart meters, are suited for smart grid. Testing should be based on IEC 61850 standard’s edition No. 1 and edition No. 2, which soon will be available in full to offer electricity producers, consumers and grid operators guidance in selecting and integrating individual devices. This is especially significant for smart meters because the elements link private consumers and energy suppliers. Many meters implemented so far do not offer an adequate level of security. Available protection profiles, encryption, anonymization and pseudonymization of collected data must be expanded and improved. Information provision, quality and security are key to the broader smart grid that extends beyond consumers. Grid owners and operators must collect information from all energy producers connected to their grids. This may be a complex task for smaller energy producers that do not have specialist know-how. They must consider the technical requirements to be fulfilled when planning a new plant. The owners and operators of existing plants should learn about the upgrades required to integrate into the smart grid and how to upgrade in the most cost-effective manner.
Peter Pfisterer is head of the smart grid laboratory at TàƒV SàƒD.
Reach him at +49 (89) 5791-3372 or email@example.com.
Christian Dirmeier is product manager smart grids at TàƒV SàƒD.
Reach him at +49 (89) 5791-1026 or firstname.lastname@example.org.
TàƒV SàƒD”Ëœs Smart Grid Competence Centre supports companies throughout the world, providing across-the-board strategic consulting services from planning to implementation. Technical components and systems testing carried out in TàƒV SàƒD”Ëœs in-house smart grid testing laboratory make up the second service segment. The service portfolio covers devices and systems laboratory testing, comprehensive consulting services on the design and development of new devices, smart grid integration of components and systems and smart grid optimization, as well as special training for electricity producers and consumers.
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