The New Multi-output High-voltage Isolated Power Supply And Its Applications In Solid-state Short-circuit Current Limiter

This paper presents a new kind of power supply with isolated and multiple outputs, which may be applied to the solid state fault current limiter.On the basis of the summarizing important applications of Power Electronics in Power System such as the fault current limiter, the paper especially introduces sorting and development of the solid state fault current limiter. The requirements regarding driving unit are introduced in the paper, according to its particularity and importance on the novel solid state fault current limiter.Based on a Chinese Patent, a novel power supply with multiple isolated outputs for driving of thyristors used in the solid state fault current limiter is developed here. The number of outputs of the proposed power supply is great enough for driving of all the thyristors used in the limiter. It is only using one high voltage cable to serve as the common one-turn primary winding for all the output transformers. In addition, the isolation voltage level for the transformers can be made very high. Their number and site can be changed very easily to meet the requirements on thyristors in the limiter.The successful development of this novel Power supply is to ensure the complete of the experimental prototype with the rated value of 400V/300A and the maximum short circuit current of 1500A. The improved novel power supply effectively fulfils all requirements provided by the currently-investigated and industrial-test prototype with the rated value of 10kV/lkA and the maximum short circuit current of 6kA.Compared with a power supply made in other ways with the same capacity, the same number of outputs and the same isolation voltage, the power supply discussed in this paper has the advantages of small in size, light in weight, high efficiency and reliability, low cost and so on. The proposed power supply is also well suitable for use in high power application such as electric utility and large motor drive systems where a great number of power electronic devices are involved.