Demo 2 Special Workshop: multivendor interoperability in HVDC systems

For the first time, HVDC control cubicles from different vendors were wired into the same real-time simulation set-up and run together. That was the centrepiece of the fourth BEST PATHS special workshop, held in Paris La Défense on 5 June 2018 and organised by the French transmission operator RTE, which led Demo 2.

The problem was easy to state. Every VSC-based HVDC link in Europe had so far come from a single supplier, so its converters had never had to cooperate with someone else’s. Plans for multi-terminal links and DC grids would change that, and Demo 2 was the first systematic attempt to find out what breaks when they do, using offline and real-time simulation with world-leading manufacturers.

Morning at Coeur Défense

The talks took place at the Coeur Défense conference centre on the Esplanade du Général de Gaulle. Olivier Despouys of RTE welcomed the audience and presented the demonstration; Olivier Grabette, executive vice president and board member at RTE, gave the introduction; Miguel Lorenzo of Red Eléctrica de España summarised the wider project. Pierre Rault of RTE and Dimitrios Vozikis of the University of Strathclyde presented the results with offline models, Christian Wikström of ABB and Pierre Rault covered the experience with control cubicles, and Alexandra Burgos of Red Eléctrica joined Despouys for the overall lessons and recommendations.

Afternoon in the lab

After lunch the group walked about 30 minutes to RTE’s real-time laboratory in the Tour Marchand in Courbevoie. There, three parallel sessions of up to 25 people each covered the Demo 2 hardware and grid operator experience, the live multivendor cubicle demonstration, and an electromagnetic transient study of converter interoperability.

The results cut both ways. According to RTE’s press release the next day, the investigations proved that interoperability issues exist and also solved some of them, work done with ABB, Red Eléctrica, Elia, the University of Strathclyde and École Centrale de Lille. Despouys did not soften the stakes: “The lack of interoperability for electric components will create a bottleneck in the development of the European energy infrastructures.”

The recommendations that followed were addressed to grid operators and standardisation bodies, with guidelines meant to feed ENTSO-E’s network code drafting teams and standards work at CENELEC and IEC; the Demo 2 page explains the method, and the HVDC explainer covers the converter technology itself.