Electromagnetic–thermal–structural coupling analysis of the ITER edge localized mode coil with flexible supports

In a fusion reactor, the edge localized mode（ELM） coil has a mitigating effect on the ELMs of the plasma. The coil is placed close to the plasma between the vacuum vessel and the blanket to reduce its design power and improve its mitigating ability. The coil works in a high-temperature,high-nuclear-heat and high-magnetic-field environment. Due to the existence of outer superconducting coils, the coil is subjected to an alternating electromagnetic force induced by its own alternating current and the outer magnetic field. The design goal for the ELM coil is to maintain its structural integrity in the multi-physical field. Taking as an example the middle ELM coil（with flexible supports） of ITER（the International Thermonuclear Fusion Reactor）, an electromagnetic–thermal–structural coupling analysis is carried out using ANSYS. The results show that the flexible supports help the three-layer casing meet the static and fatigue design requirements. The structural design of the middle ELM coil is reasonable and feasible. The work described in this paper provides the theoretical basis and method for ELM coil design.

Dynamic characteristics of large permanent magnet direct‐drive generators considering electromagnetic–structural coupling effects

Dynamic characteristics of large permanent magnet direct‐drive generators(PMDGs)considering electromagnetic–structural coupling effects are analyzed in this study.Using the conformal mapping method,the scalar magnetic potential of the air gap magnetic field considering the slot effect is calculated.On the basis of the discrete current element and magnetic equivalent circuit model,the local magnetic saturation effect of the stator and rotor is quantitatively simulated and the air gap magnetic field intensity distribution is obtained via numerical simulation.A series of uniformly distributed equivalent electromagnetic springs are introduced to develop an electromagnetic–structural coupling finite element PMDG model.The proposed air gap field analysis method is verified by the finite element analysis results.On the basis of the test platform for the Goldwind 1.5MW PMDG,both modal and dynamic response tests for the stator/rotor coupling system are conducted,and the results are compared with the natural frequencies,mode shapes,and vibration responses obtained using the numerical model.The effects of the air gap length and rotor speed on the natural frequencies of the coupling system are analyzed.The proposed model has the potential to accurately evaluate the PMDG vibration energy,avoiding resonance points,and maintaining stable operations of the unit.