Doubling down on America’s largest transmission system
American Electric Power (AEP) is keeping energy transition in sight using digital twin software to accurately model and predict growing electricity fluctuations.
Make no doubt, the future is electric. And it has this utility seeing double. American Electric Power (AEP) will soon have a digital twin of the largest transmission system in the U.S. The advantages? Centralized data, enhanced asset management and simplified grid planning – plus the ability to see into the future of their customers’ needs.
By Chris Kraul
As grid planning and operations were becoming more complex, AEP Transmission determined that traditional manual practices for sharing model data amongst their separate utility systems, while industry standard, were no longer optimal. AEP knew they had to sharpen their digital awareness and data exchange tools. Their three core network models – Reliability Coordination efforts, the Transmission Planning Organization, and the Protection and Control environment – historically have been maintained in three different lines of the business and managed separately, but now needed to be synchronized.
“Electricity is the future and it’s very important that utilities be forward-thinking so that we can integrate energy renewables such as wind and solar into the changing utility landscape,” says Eric Hatter, Business Technology & Strategy Manager at AEP Transmission.
How could the utility, serving 5 million customers, more efficiently integrate all the incoming data within one comprehensive modeling software system to improve reliability, streamline analytics, and enhance the network to better manage the growing contribution to the grid of energy from renewable sources? AEP selected Siemens to lead this critical transition by installing an “electrical digital twin.” The specialized electrical power transmission system modeling and analysis software PSS®ODMS is the foundation of the new system. The new system is currently undergoing testing and will be fully operational in late 2019.
Seeing in real time and into the future
Digital twins are virtual computer models of what is taking place in day-to-day reality. They are used not only by electric power utilities, but in a host of other industries, too, including car makers, aerospace manufacturers, and health care providers to monitor real-time operations, improve efficiency, and simulate the future.
“A digital twin is basically an accurate digital representation of a physical system,” says Mike Carlson, who heads Siemens’ North America Digital Grid business. “All the components that exist within it are represented at a connective, specific device level and allow a number of analytical and optical views of what the system is doing, is able to do and what it is projected to do.”
Digital twins allow utilities to take modeling a step further by enabling operators to run simulations of hypothetical situations such as partial system failures, projected load growth, a boom in electric car usage or the impact of a new wind farm in the neighborhood, to name just a few, and then to make contingency plans. Within AEP, the electrical digital twin will provide a foundation to enable better coordination of network model information across several business functional domains, provide centralized management of that information, and allow for a standards-based approach for sharing utility modeling data across the enterprise.
A model of the entire grid
The digital twin core PSS®ODMS features intuitive, easy-to-use computer graphics. The out-of-the-box user interface can provide multiple views of the electric transmission network by generating interactive substation diagrams, as well as “world views” of the grid. Comprehensive tabular views and hierarchical views of equipment data help users quickly navigate the network.
Although Siemens has installed digital twins for other power utility transmission networks in the past, the AEP project is the largest and most complex to date, partly because AEP’s presence extends from Virginia to Texas. Not only is the digital twin enhancing the utility’s previous data governance strategy, the system has to be flexible enough to accommodate its continued evolution by allowing 40 AEP planners in five states access to the model and to make changes as needed, too.
Centralizeddata and monitoring technologies
AEP also wanted a system to help it automatically perform functions that up to now have been executed manually, such as assuring data compliance with the number of regulatory agencies in the eleven states it serves. The system will ensure reliability and reduce outages in a network that consists of conductors (cables) made of different physical materials spanning varying topographies and differing climates.
One of the biggest highlights for Siemens was integrating three different AEP modeling technologies for planning, operations, and protection by means of new software that is able to extract data in a common information format (CIM) and then import it into the new PSS®ODMS platform, which is referred to by AEP operators as T-Nexus.
“These three core network models historically have been maintained in three different lines of business and managed separately, but they needed to be centralized and synchronized,” says Hatter, a 30-year AEP employee.
However, the LCC is no boring assembly line. No two turbines are alike. The geometry is always different, depending on the number of stages, extractions and the type of exhaust system. In addition, some turbines are up to 40 to 50 years old. The oldest machines still in operation date to the 1920s; and there are more than 50,000 active Siemens steam turbines worldwide. Because of this large global market, the company is also cooperating with LCC sites in India, Brazil and in the future in the USA. Siemens is also developing mobile LCC units - "this also helps to save time and money," says Scheller. In addition, demand continues to grow: The LCC is increasingly servicing not only steam, but also compressors and gas turbines.
Enough talk. From his control desk, Wexler presses a button that allows the door to the large working area of the LCC to squeakily close. He checks the settings for the Saudi Arabian rotor, then starts the welding process, which starts at its bearings. Cameras film the process and stream the images to a computer screen. Just a day later, Wexler checks the results with a microscope. Some of the coatings are so thin and fine-grained that they cannot be seen with the naked eye. He is satisfied. But not surprised.
Accurate modeling for future energy trends
AEP is also relying on its new “electrical digital twin” software to model, and thus help it predict and plan for future grid needs at a time when changing consumer usage trends and power generation sources are putting stress on utility decision makers. For example, planners must anticipate growing electricity demand in coming years for electric-car charging even as residential use in general is declining due to more energy efficient appliances.
The system empowers operators to simulate hypothetical additions to generation capacity from renewable sources, including the growing number of homeowners who are generating their own power with solar panels or wind power units and selling excess electric power back to the utility.
“Over the last few years, we have seen a lot of coal-fueled units retired and replaced by more wind and solar generation,” says David Ball, Managing Director of AEP’s transmission operations. That has heightened AEP’s need for accurate models to “feed our situational awareness tools.”
- Greatly reduce the time and the costs associated with manual model coordination efforts, both internally as well as with external entities
- Establish the infrastructure and data governance foundation to support AEP’s strategy of capital investment in transmission improvements and expansion
- Provide a model alignment solution that will help drive the implementation of advanced technologies, such as predictive asset health analytics, synchrophasors, etc.
Chris Kraul is a freelance writer based in Bogotá, Colombia.
Combined picture and video credits: Siemens AG, Patricia Tarczynski, independent medien-design
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