Research on short circuit test of ITER DC line disconnector

In this paper, firstly, the fault current of DC line disconnector is analyzed based on international thermonuclear experimental reactor (ITER) poloidal field(PF) converter system to propose the short-circuit test requirement of ITER DC line disconnector. Then, the short-circuit test scheme is designed based on the DC test platform in Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), including the selection of transformer tap position, the calculation of the DC voltage corresponding to the test current and so on. Finally, the feasibility of the test scheme is verified by simulation and experiment, and it is proved by the test results that the fault suppression ability of DC line disconnector meets the requirement of ITER converter operation. By analysis and calculation, 350 kA test current needs the DC voltage 270 V. In the test, if the DC voltage is preset to 270 V, the test current is less than 350 kA. After the DC voltage is preset to 300 V, the peak of test current can reach 362.5 kA and the duration of more than 350 kA can be up to 100 ms. The difference between the actual preset DC voltage and its theoretically calculated value is 30 V, which is caused by the voltage fluctuation of the power grid.