Ran Zhang1, Feng Liu2, Xiuhe Wang1, Stuart Crozier2
1School of Electrical Engineering, Shandong University, Jinan, Shandong, China, People's Republic of; 2School of Information Technology & Electrical Engineering, University of Queensland, Brisbane, Queensland, Australia
The design and optimization of quench protection circuit for magnetic resonance imaging (MRI) superconducting magnets require extensive and accurate information about quench behaviors under the action of different quench protection systems. Conventional quench simulation with analytical approach has difficulty in dealing with nonlinear problems. In this study, a commercial three dimension FEM software OPERA-3D/QUENCH is employed to address the quench characteristics of actual 1T clinical MRI magnets with both symmetric and asymmetric configurations. Passive and active protection systems are involved to identify the influence of different protection circuit on the quench performances. The modeling process and setup for the solving are discussed in detail. Critical safety-related quantities such as maximum temperature, current and voltage of superconducting coils and the variation of fringe field during the transition are provided comparatively. By comparing the correspondent simulation results, it is concluded that the one type of quench protection system is not applicable for all the superconducting magnets and the selection of quench protection circuit demands considerable investigation.