Superconductor Roebel cable

Superconductor Roebel cable allows superconductors to work with high AC currents. We have developed the world's first large-scale manufacturing capability.

The science

Superconductors have zero resistance in DC conditions, but in AC conditions, eddy currents can be created. This causes loss or heat generation which, though only small, requires additional energy to remove at cryogenic temperatures. It brings a loss of stability, reduces efficiency, and can lead to quench.

The current in a superconductor tape has a limit—usually in the hundreds of amperes. But larger machines need much higher currents—potentially thousands of amperes. Roebel cable offers a solution. It is ideally suited for coil and magnet winding and offers enhanced performance under ramping and AC operation. To make Roebel cable, wires are first cut to a serpentine shape and then planetary wound.

Many people thought it would be impossible to make Roebel cable in a practical manufacturable process. But with some great engineers and lots of enthusiasm, that’s exactly what we managed to do.

Impact and potential

Superconductor Roebel cable is a niche research-level product. It is the best conductor option to allow superconductors to work with high AC currents. It is most suited to transformers, generators, and motors, and is a standard option for the power industry.

Paihau—Robinson Research Institute is the only place in the world with the capability to manufacture superconductor Roebel cable at large scale. To date, it has successfully proven the performance of Roebel cable in a 1 MVA distribution transformer, and the performance of the cable has also been demonstrated by CERN in a magnet prototype.

We enable large and flexible currents by repurposing a hundred-year-old technique and applying it to high-temperature superconductors.

The people

Dr Nick Long is the director of Robinson Research Institute. The resourcefulness and enthusiasm of the diverse and world-class multidisciplinary team working at Robinson never ceases to amaze him. The development of Roebel cable manufacturing processes is one such example.