The high voltage power supply based on pulse step modulation for auxiliary heating system on fusion device

Abstract

The auxiliary heating systems have already been built in HL-2A nuclear fusion experimental device. The DC high voltage (HV) pulse power supplies are the important components of the auxiliary heating systems. There are two existing HV power supplies which are based on thyristor voltage regulating and star-point controlling technology, respectively. In order to do some research in H-mode, it is necessary to raise the efficiency and improve output heating power and performance of the HV power supply system. So it needs the high requirements of power supply as fellows: the higher power HV pulse width, shorter dynamic response time and less released energy to the load at HV power supply switching off. The structure, control principle and algorithm, calculation formula of the filter for the PSM have been described in this paper. The effects of stray parameters in the multiple secondary transformers have been discussed. The SPS module can meet the requirements. The PSM power supply has been built and its maximum output is about 80kV/100A.The results show that the pulse step modulation, high efficient frequency of the output, the small energy of the output filter, short protection time, high output power and low ripple can be achieved. The stray parameters can meet the requirements of the system. The outputs of the power supply show that this kind of power supply has the performances of fast dynamic response, high output power, high voltage, high stability, small stored energy, the continuous output voltage adjustment.