RFX is a fusion machine based on the toroidal magnetic confinement. The Ohmic Heating (OH) coils of this machine are fed by a 50 kA current and produce a maximum induction value of 4.5 Tesla. Four busbar systems feed these coils. Since the electrical terminals of the OH coils are located in the high field region of the machine, both the terminals and the feeding busbars are subjected to a high electromagnetic load, which involves severe mechanical problems. The requirement for a low stray field caused by the electrical connections has also to be taken into account. From a preliminary analysis, the most critical points of the structure revealed to be the copper-insulation interface inside the coil terminals and the bolted joints between busbars and coils. The field configuration, together with the geometry of the busbars, gives rise to a very complex load distribution, which required the use of the finite element method to perform a more precise stress analysis. A wide set of stress analyses on several possible design solutions has shown that stresses can be remarkably reduced with a careful choice of the busbar route. In the paper the basic design criteria, the analysis procedures, results and the manufacturing solution are exposed in detail.
RFX Ohmic heating Coils: design of the electric terminals and busbars
CHITARIN, GIUSEPPE;
1989
Abstract
RFX is a fusion machine based on the toroidal magnetic confinement. The Ohmic Heating (OH) coils of this machine are fed by a 50 kA current and produce a maximum induction value of 4.5 Tesla. Four busbar systems feed these coils. Since the electrical terminals of the OH coils are located in the high field region of the machine, both the terminals and the feeding busbars are subjected to a high electromagnetic load, which involves severe mechanical problems. The requirement for a low stray field caused by the electrical connections has also to be taken into account. From a preliminary analysis, the most critical points of the structure revealed to be the copper-insulation interface inside the coil terminals and the bolted joints between busbars and coils. The field configuration, together with the geometry of the busbars, gives rise to a very complex load distribution, which required the use of the finite element method to perform a more precise stress analysis. A wide set of stress analyses on several possible design solutions has shown that stresses can be remarkably reduced with a careful choice of the busbar route. In the paper the basic design criteria, the analysis procedures, results and the manufacturing solution are exposed in detail.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
