Planning high-voltage direct current grids for a carbon neutral future
Europe’s drive to transition from fossil fuels to renewable energy sources is set to bring about significant changes in power transmission networks. The EU-funded HVDC-WISE(opens in new window) project is working on reliable and resilient high-voltage direct current (HVDC) grid configurations that will help speed up the integration of renewables across the continent and lay the foundations for a future integrated European transmission system. Commonly used for long-distance power transmission, HVDC grid systems are key enablers for a carbon-neutral energy system. They require fewer conductors and lose less power than equivalent alternating current (AC) lines, therefore transferring power more efficiently over long distances. They are also able to deliver renewable energy to certain hard-to-electrify sectors. These and other properties make them the best technology to manage Europe’s energy transition.
Boosting efficiency and accuracy
One of the advances HVDC-WISE has achieved in HVDC equipment modelling is the adoption of the functional mock-up interface (FMI), an open standard for exchanging dynamic simulation models between different tools in a standardised format. In a world of increasingly complex power systems, mathematical models and simulation tools are faced with certain limitations. They are often only applicable to specific subsystems within interconnected networks, typically incompatible with other tools and have intellectual property restrictions, all of which hinder research and advancements in power electronics and transmission systems. HVDC-WISE’s adoption of the FMI is helping to tackle these issues by streamlining the model exchange process and improving the efficiency and accuracy of power system simulations. Electrical engineer Florent Morel of project coordinator SuperGrid Institute, France, writes in an ‘EE Times Europe’ article(opens in new window): “Supported by over 200 tools—including industry leaders such as dSPACE, MATLAB/Simulink, DIgSILENT PowerFactory, and OpenModelica—FMI enables seamless interoperability while protecting proprietary knowledge. Its black-box approach allows models to be shared without exposing sensitive details, resolving conflicts between IP security and collaborative innovation. By standardizing model exchange, FMI eliminates redundant development efforts and bridges compatibility gaps between tools (e.g. MATLAB/Simulink and DIgSILENT PowerFactory). This accelerates simulation-based studies, empowering engineers to integrate validated models from diverse platforms into cohesive systems, even when dealing with large, heterogeneous power networks.”
Leveraging dynamic phasors
Another innovative approach by HVDC-WISE is the use of dynamic phasors to model the interactions between the AC and DC parts of the grid more accurately and efficiently. Traditional root mean square (RMS) and electromagnetic transient (EMT) simulations have certain limitations when it comes to modelling power electronic converters such as those used in HVDC grids. RMS simulations are often too simplified and EMT simulations require very small time steps and are too computationally intensive. “Dynamic phasor modeling offers a middle ground,” states Morel. “First, the increased time step in the dynamic phasor modeling domain has a smaller effect on the simulation accuracy than EMT … Second, dynamic phasor modeling represents electrical grid dynamics that are not available in RMS simulations.” The HVDC-WISE (HVDC-based grid architectures for reliable and resilient WIdeSprEad hybrid AC/DC transmission systems) project’s new approaches to modelling and simulations are described in a report titled ‘Technology modelling’(opens in new window). The advancements in HVDC grid architectures will help further Europe’s transition to sustainable energy. For more information, please see: HVDC-WISE project website(opens in new window)
