Key facilitators of HVDC systems for advanced electrical infrastructures

The aim of this paper is to provide insights, from a manufacturer’s perspective, into HVDC projects from planning and commissioning through to commercial operation, and to discuss selected topics in greater depth to identify opportunities for improvement in the transmission industry and help resolve supply bottlenecks.

The focus of the discussion is on key facilitators, starting in the planning phase, where the use of a functional specification follows the European “Grid Action Plan” request to streamline and consolidate project requirements and supply chains. Based on ongoing project execution, standardized HVDC portfolio solutions are discussed, together with guidance on selecting the appropriate solution for a specific HVDC project. It is also highlighted that a standardized portfolio still allows intermediate solutions to address specific boundary conditions. For main-circuit design, two examples are analysed as facilitators for HVDC projects. First, the

AC feeder of an HVDC converter station is discussed to illustrate the coverage and checks needed when applying readily available, homologated equipment. Second, the converter transformer is considered because it forms a natural interface between the AC and DC sections, where dedicated project alignment is required to meet customer-specific engineering rules and functional HVDC requirements. A further motivation is the major role of converter transformers in the overall affordability of HVDC schemes and the supply security of manufacturers. Specifically, this paper introduces, as a simplification, a minimum viable converter-transformer solution for a 2 GW bipole scheme for integrating offshore wind power.

From a manufacturer’s perspective, an industrialized Control & Protection (C&P) engineering and testing approach, based on model-based engineering MBSE principles, demonstrates how

C&P engineering can evolve from a traditional sequential verification activity into an integrated, schedule-driven workstream that supports the timely and reliable delivery of advanced HVDC systems. By consistently applying a structured workflow—from offline simulation to real-time hardware-in-the-loop (HIL) validation and staged factory and site testing—engineering activities can be parallelized, test scopes optimized, and schedule risk mitigated. Key enablers for reducing time to operation include automated software-in-the-loop

(SIL) verification, selective HIL testing, early decoupling of factory and site activities, and

HVDC stand-alone commissioning concepts. The discussion illustrates how these enablers contribute to accelerated execution without compromising system quality or functional robustness.