8. Power supply testing facility
The power supply testfacility aims to solve the key issues of current tokamak coil power supply,develop the advanced (next generation) tokamak coil power supply, and supportthe research and test on large current super-conductive meganet systems.
SystemDescription and main parameters
The power supply testfacility includes coil power supply system, voltage source converter andcontrol system. The whole system layout is shown in following figure.
1) Thecoil power supply willfeed 100 kA to the superconductive coil. And in case of quench, it will be ableto interrupt 100 kA DC current, and dissipate 1 GJ power within 0.5 s with highreliability. It includes a 250 V, 100 kA thyristor converter system, a 1 GJ,100 kA quench protection system and a 25 MVAr statcom reactive powercompensation system.
1) Thevoltage source converter will adopt the full-controller power electronic device to accomplish a powersupply with:
Ratedcurrent: ±60 kA
Ratedvoltage: ±3 kV
Response time: 0.2 ms
Power factor: ≥0.9
This converter will replacethe traditional thyristor-based converters with the advantages of low reactivepower, less harmonics, and better dynamic performance. Moreover, thistechnology may finally solve the low frequency harmonic oscillation problemscaused by the compatibility between the Tokamak power supply and the grid andmake it feasible to connect the large power Tokamak device to the grid.
The followingkey technologies is expected to be solved by constructing the power supply testfacility:
• Mechanism of low-frequency harmonic andreactive power ;
• Newtopology and control strategy to deal with large and fast (~ms) reactive powervariation;
• Distinguish of high power arc under DC andinductive load;
• Dynamic process of multi-stage commutation;
• Ultra-fastaction of large current pyobreaker;
• Multiphysical filed coupling model and analysis on large current dynamic operationequipments.
• New advanced tokamak power control technology
Thepower supply test facility can not only be an example to lead an innovation ofthe fusion high-power supply, but also be devoted to test the super-conductive meganets,industrial electrical equipment such as converters, reactors, DCdisconnections, DC switches, fuse and power electronic switches and devices.