HVDC-Wise project explores concepts and proposes solutions to foster the development of large HVDC based transmission grid infrastructures, able to bring benefits in terms of resilience and reliability to the existing electrical system and capable of integrating the forthcoming large amount of renewable energy. To do so, 5 ambitious specific objectives in line with the HORIZON-CL5-2021-D3-02-08 call expectations were selected: -Develop a complete reliability-&-resilience-oriented planning toolset (metrics, methodology, tools) with appropriate representation of future HVDC-based grid architecture concepts to fulfil TSOs’ resilience and reliability needs. -Propose and compare on generic cases, different HVDC-based grid architecture concepts fulfilling functional requirements relative to TSO’s resilience needs for the widespread AC/DC system. -Validate resilience-oriented planning toolset and the HVDC-based grid architecture concepts on three realistic use cases. -Identify, assess, and model emerging technologies for HVDC-based grid architecture concepts needed for the deployment of widespread AC/DC transmission grids. -Prepare for the adoption and deployment of the proposed solutions by the industry. HVDC-Wise is a multidisciplinary project engaging 14 partners from 11 countries covering the academic (5), TSOs (4) and industrial worlds (5). An implementation plan is presented in the form of 8 work packages, 6 of which are technical in nature. Synergy in communication and dissemination by the several partners and stakeholders will permit to maximize the HVDC-Wise project impact. Solutions to overcome the fundamental technological barriers as well as appropriate deliverables, tasks, milestones, and risks to complete the project objectives in due time are presented. HVDC-Wise proposes, designs, and validates HVDC-based grid architecture concepts enabling the deployment of reliable, resilient widespread AC/DC transmission grids to achieve the European energy transition.

To unlock multi-vendor HVDC grids and foster the transition of the European energy sector at large scale, InterOPERA proposes a coordinated approach between a diverse, high-level group of industries at the forefront of RES development and grid management. 4 HVDC vendors, 8 TSOs, 2 wind turbine vendors and 3 wind park developers bring their industrial knowledge and practical abilities to make future HVDC systems mutually compatible and interoperable by design, and to improve the grid forming capabilities of offshore and onshore converters. Foreseen and planned HVDC projects will be analysed to define a demonstrator case study. The resulting system-level design will be usable as a guidance to coordinate offshore network planning. This new way of framing the European grid architecture and topology will ensure forward compatibility for future seamless system expansion. Interoperability of control and protection systems will be de-risked through the execution of all necessary activities concurring to the implementation of a real-time physical demonstrator. Concrete results will be delivered through this practical work: detailed functional specifications for each subsystem, standardised models, simulation platforms and interaction study processes, multi-vendor cooperation agreements. Those frameworks will be generalised into operational and strategic tools available to all European stakeholders for the development of multi-terminal HVDC grids that will enhance offshore wind development and integration. Solutions for multi-vendor project procurement, compliant with existing and future regulations, standards and laws, integrating the technical specifications and interoperability assessment tender stages, will be provided to pave the way to the first real-life projects in Europe. External stakeholders will be involved in two-way consultation workshops to maximise the uptake of InterOPERA’s key exploitable results. Recommendations to grid codes and standards will be issued.

By 2020, several areas of the HVAC pan-European transmission system will be operated with extremely high penetrations of Power Electronics(PE)-interfaced generators, thus becoming the only generating units for some periods of the day or of the year – due to renewable (wind, solar) electricity. This will result in i) growing dynamic stability issues for the power system (possibly a new major barrier against future renewable penetration), ii) the necessity to upgrade existing protection schemes and iii) measures to mitigate the resulting degradation of power quality due to harmonics propagation. European TSOs from Estonia, Finland, France, Germany, Iceland, Ireland, Italy, Netherlands, Slovenia, Spain and UK have joined to address such challenges with manufacturers (Alstom, Enercon, Schneider Electric) and universities/research centres. They propose innovative solutions to progressively adjust the HVAC system operations. Firstly, a replicable methodology is developed for appraising the distance of any EU 28 control zone to instability due to PE proliferation and for monitoring it in real time, along with a portfolio of incremental improvements of existing technologies (the tuning of controllers, a pilot test of wide-area control techniques and the upgrading of protection devices with impacts on the present grid codes). Next, innovative power system control laws are designed to cope with the lack of synchronous machines. Numerical simulations and laboratory tests deliver promising control solutions together with recommendations for new PE grid connection rules and the development of a novel protection technology and mitigation of the foreseen power quality disturbances. Technology and economic impacts of such innovations are quantified together with barriers to be overcome in order to recommend future deployment scenarios. Dissemination activities support the deployment schemes of the project outputs based on knowledge sharing among targeted stakeholders at EC level.