Jinchao Li

Prototype Design and Test of ITER PF Converter Unit

This paper presents the design and testing of the full scale prototype of the international thermonuclear experimental reactor (ITER) poloidial field converter unit (PFCU), which is mainly composed of converter transformer, converter module, external bypass, and dc reactors with a rated capacity of 82 MVA and a rated dc current of 55 kA. Considering the space limitation, the high safety and reliability requirements, the nonsame-phase antiparallel connection structure, and the fault suppression capability criterion are applied in the prototype design. After the completion of the preliminary design of the PFCU in summer 2012, the detailed prototype structure design and the manufacturing of the PFCU were launched and completed at the end of 2013, then the following main type tests, including short circuit current test and temperature rise test on the main components of the PFCU, have been done on the ITER power supply test platform at ASIPP site. In addition, the PFCU integration test has also been done to verify the system operation performance. The prototype test results are well in compliance with the design requirements of the ITER PF converter system. It indicates that the full scale prototype research and development of PFCU has been accomplished successfully.

Full scale prototype research and development of the ITER PF converter unit

This paper presents the design, manufacturing and testing of the full scale prototype of the ITER Polodial Field Converter Unit (PFCU) for the coil power supply system of the ITER superconducting Tokamak. The PFCU is mainly composed of converter transformer, converter module, external bypass and dc reactors with a rated capacity of 82 MVA and a rated dc current of 55 kA, which is also required for the Fault Suppression Capability (FSC) criterion. After the completion of the preliminary design of the PF converter package in summer 2012, the detailed prototype structure design, manufacture of the PFCU were launched and completed at the end of 2013. Then the following main type tests, including short circuit current test and temperature rise test on the main components of the PFCU, have been done on the ITER power supply test platform at ASIPP site and are described in this paper. And the PFCU integration test has also been done to verify the system operation performance. The prototype test results are well in compliance with the design. It indicates that the full scale prototype of PFCU can fully meet the design requirements of ITER PF converter system.

R&D of High Current Balance Reactors

The design of high current balance reactors used in the ITER DC testing platform is presented, which is verified by simulations with finite element method software, and the reactors are fabricated and tested according to the design output. These reactors are chosen as multilayer multi-turn structure and cooled by water. The multilayer multi-turn structure is usually selected by some high voltage reactors, but is seldom used in high current situations. The analysis and testing results indicate that the multilayer multi-turn structure is also feasible for high current reactors with many advantages, and is of considerable significance to similar applications.

MHD Instabilities and Their Effects on Plasma Confinement in Large Helical Device Plasmas with Intense Neutral Beam Injection

MHD stability of the Large Helical Device (LHD) plasmas produced with intense neutral beam injection is experimentally studied. When the steep pressure gradient near the edge is produced through L-H transition or linear density ramp experiment, interchange-like MHD modes whose rational surface is located very close to the last closed flux surface are strongly excited in a certain discharge condition and affect the plasma transport appreciably. In NBI-heated plasmas produced at low toroidal field, various Alfven eigenmodes are often excited. Bursting toroidal Alfven egenmodes excited by the presence of energetic ions induce appreciable amount of energetic ion loss, but also trigger the formation of internal and edge transport barriers.