1. Development of R&I activities, methodologies and tools for at least two of the sub-topics in A (a, b or c) and B. These can be developed/complemented among them and/or with others pertinent to each sub-topic:

A) Protection:

a. Methodology to assess admissible temporary loss of transmitted power in case of DC fault:

• AC-DC transient stability, when DC transmitted power is temporarily and partially interrupted, in case of a DC fault.
• Impact of reactive power supply transient interruption (converter blocking).
• In case of MVDC/HVDC-connected Off-Shore Wind farm: coordination of control actions from MVDC/HVDC and wind turbines.
• Anticipation of new system dynamics due to high PEID penetration.
• Impacts of partially selective and non-selective versus fully selective DC fault-clearing strategies.
• Recommendation for AC-DC system design and DC protection design.

b. Multi-vendor interoperable MVDC/HVDC grid protection

• Improved methodologies for the determination of functional requirements of DC grid protection in a technical and vendor neutral manner.
• Standardised validation tests for de-risking interoperability issues.
• Specification of protection component and auxiliary ratings.
• DC substation Communication architecture and protocols (e.g., IEC 61850 for DC).
• Protection system simulation models and information exchange.

c. HVDC grid protection strategies and design

• Methodologies for the protection of mixed (OHL/cable, bipolar/monopolar) DC grids.
• Methodologies to optimally determine the optimal MVDC/HVDC grid protection system, including combined selective, non-selective and partially protection schemes within the same DC grid.
• Development of converter assisted MVDC/HVDC grid protection.
• DC station design and optimisation from protection point of view.
• AC & DC side protection system functional design for fully selective, non-selective and partially selective fault clearing strategies, including the connection to low inertia AC systems

B) Congestions in AC or DC grids:

• Simulation, analysis, design, development, test and demonstration of advanced Power Electronics-based equipment inserted appropriately in specific points in the grid to decongestion the lines or cables.
• Cost Benefit Analysis compared to other solutions (e.g., the use of DC systems, etc.) at system level and covering the operating life of the equipment.

2.  Demonstration, test and validation of the activities developed in (1) in at least two pilots in different EU Member States/Associated Countries.