The protection strategy of the system will be defined to ensure the safety of the superconducting cables and converters, as well as maximize the availability of the power transmission. One key protection equipment is the Resistive Fault Current Limiter (RFCL), which has to carry the same load current as the superconducting cable. An RFCL module operating at 10 kA will be designed, manufactured, and tested during the project.

Key activities

The work package is structured into two main tasks:

1. System architectures and protection

DC system architectures and select reference case studies will be investigated for the superconducting cable technologies developed in WP2, WP3 and WP4. In particular for offshore renewable export, the different conversion architectures will be reviewed, allowing for the suppression of the high-voltage DC offshore conversion platforms and the direct transmission from the windmill output.

Based on the chosen system architecture and protection strategy, transient currents and voltages will be evaluated in order to specify the requirements for the superconducting cable and the different components of the protection system such as circuit breakers and fault-current limiters.

2. Fault current limiter at 10 kA

Relying on the specifications of the previous task, this task will demonstrate one module of a resistive superconductive fault current limiter with 50 kVDC voltage rating and 10 kADC current rating, needed for protecting the superconducting cables developed in the project during an external fault.