Magnetics Business & Technology - Fall 2013 - (Page 16)

APPLICATION FEATURE Simulation Accuracy Helps Pioneering Superconducting Generator Developments Factory testing of a pioneering superconducting generator for hy- with its own suite of analytical programs for generators, which droelectric applications from GE Power Conversion business has have been developed and refined over many years at the compademonstrated a high correlation between the accuracy of the Opera ny’s Rugby site. The finite element approach provided considerelectromagnetic simulation tool used during the design process, ably more accurate predictions for some parameters, as well as and the performance of the finished product. The proven fidelity offering the ability to accurately evaluate new mechanical shapes of the simulation, for such a complex electrical and geometries without modifying the underlymachine with 28 poles, could help GE to creing formulas. This versatility was particularly ate advanced solutions for numerous emergent helpful for the superconducting generator desuperconducting applications in markets such velopment as it features an unusual airgap and as wind, wave and hydroelectric power generapole layout. tion, and electric motors for ship propulsion. In addition to accurate predictions, the Op The testing results were for the Hydrogenie era simulator also provided the platform for GE generator for hydroelectric applications, which to optimize the generator development before was developed by a team from GE and partconstruction. As part of its work for this EUners, with financial support from the EU. The funded project Cobham modified its software to generator employs high temperature superconmake it simpler to simulate very large electrical ducting (HTS) wire, to provide both a step inmachines with lots of poles, by extending its crease in output efficiency, and size and weight support for two-dimensional (2D) simulation of reductions of some 70 percent when compared segments of a symmetric radial structure to 3D to a conventional electrical machine. structures. As a result, GE was able to analyze The correlation between predicted and meahundreds of concepts during the development sured results is extremely close. For example, The rotor of GE Power Conversion's process, using partial 2D and 3D simulations, the Opera finite element design tool from Hydrogenie superconducting generator, before settling on the detail of the final architecCobham Technical services predicted the ef- which was simulated before build using ture and then fine tuning the performance with Opera software. (Image courtesy of GE ficiency of the machine to an accuracy within Power Conversion.) the aid of very detailed 3D analysis. 0.1 percent of the final built product. This The resulting Hydrogenie machine has many potential advantages for the has an efficiency of more than 98 perelectrical machine developers at GE. cent, which is very high for a relatively As this was GE Power Conversion’s small output (1.7 MW) generator of this first venture into HTS generator engineertype, which is optimized for a run-ofing, the development team employed conriver hydroelectric application operating servative rules to create a machine capable at rotational speeds up to 214 RPM. of meeting the target output figure of 1.7 The generator itself has a conventional MW. The conservatism ensured that the stator. The rotor’s salient poles of lamimachine would meet the real-world specinated iron operating at room temperature fication. However, the new factory tests are surrounded by HTS field coils cooled have shown that the generator is actually to below 40 K. The rotor is surrounded capable of providing considerably more Opera software predicted the real-world efficiency of by a copper shield, which also acts as the output power than the target figure. Con- the Hydrogenie superconducting generator to an accu- outer wall of the vacuum vessel containsequently, now that the accuracy of the racy within 0.1 percent of the final built product. Devel- ing the rotor as well as a damper winding. opments to Opera enabled the 3D dynamic simulation simulator has been proven, GE develop- of this very large electrical machine by modelling only a The coils are thermally insulated from ers are confident that the Opera simulator single pole. (Image courtesy of GE Power Conversion.) the poles by a combination of the vacuum will help engineers to create cost-effective and multi-layer insulation. The coils are superconducting models for future applications. cooled by helium gas circulated through a cryogenic transfer cou “Testing proves that our superconducting generator design pling between the stationary and rotating structure. ideas work well, but also that we can predict performance with The Hydrogenie project experience is very valuable for Cobham, very good accuracy. Being able to produce very lean super- who have used the knowledge to integrate new features into the conducting models, that are even more compact and perfectly Opera software package. These new features join a growing suite matched to the application, could really make a big difference of utilities that simplify high temperature superconductor developin the cost effectiveness of projected future applications such as ment, including the industry’s first commercial tool for analyzing wind power,” said Martin Ingles, Hydrogenie project manager at the superconducting ‘quenching’ process, and special modeling GE Power Conversion. features to simplify design using HTS wire materials with their During the development and testing cycle, the engineers at GE non-linear properties, developed in conjunction with Sumitomo. also compared the finite element electromagnetic design approach 16 Magnetics Business & Technology • Fall 2013 www.MagneticsMagazine.com http://www.MagneticsMagazine.com

Table of Contents for the Digital Edition of Magnetics Business & Technology - Fall 2013

Editor's Choice
Nanocrystalline Materials for the Next Generation of Noise Suppression Solutions
Magnetic Continuously Variable Transmission
Magnets • Materials • Measurement
Simulation Accuracy Helps Pioneering Superconducting Generator Developments
Application • Component Developments
Research & Development
Industry News
Marketplace/Advertising Index
Spontaneous Thoughts: NdFeB: The First 30 Years and the Next 30 Years

Magnetics Business & Technology - Fall 2013