Collaboration aims to simplify electrical machine design

Superconducting wire producer Sumitomo Electric and electromagnetic simulation specialist Cobham Technical Services, have joined forces to offer what they describe as an advanced solution for the design of electrical machines and power equipment.

Cobham's QUENCH electromagnetic software tool for modelling the quenching process in superconducting materials now comes with a library containing comprehensive manufacturer-supplied material characterisation data for Sumitomo's DI-BSSCO bismuth-based superconducting wire. According to Cobham, the combination will 'greatly simplify' the design and prototyping stages of applying high temperature superconductors (HTS). Among the application sectors currently exploring HTS-based solutions are electricity transmission and distribution infrastructure, hydroelectric and wind turbine generators, electric motor propulsion systems for ships, and high performance magnets. John Simkin of Cobham Technical Services, said: "Design activity using HTS superconductors is growing very rapidly - driven by the maturing of HTS technology and the critical need to improve energy efficiency. This cooperation agreement provides an important means of simplifying and speeding design projects. It eliminates a major step in the design process of specifying the non-linear properties of the wire materials - which might involve testing under highly controlled operating conditions - allowing a designer to create an accurate model of an electrical component such as a coil simply by specifying the number of turns." Sumitomo Electric was the first company in the world to produce long bismuth-based superconducting wire, a material that has become an industry standard and is considered to be the major candidate for commercial HTS applications. Sumitomo's bismuth-based superconducting wire - DI-BSSCO - is made of bismuth-strontium-calcium-copper-oxygen and operates at temperatures up to 110K. The QUENCH tool for modelling the superconducting 'quenching' process - when a wire turns from a superconducting to resistive state - is available as part of Cobham's Opera CAE software suite for low frequency electromagnetic simulation. QUENCH has become the standard simulation tool for superconducting equipment, because of its sophisticated multi-physics modelling which couples the electromagnetic and thermal modelling processes. Results can be post-processed to provide users with clear views and analyses of the potentially damaging effects of quench propagation as the wire heats up and becomes resistive, including displays of the voltages between coil layers, temperature gradients, and so on. This analysis helps users to quickly find the optimal design, and incorporate protection circuitry.