Experimental verification of low-voltage power supply with 10,000-A pulse output for Spark Plasma Sintering

This paper discusses a high-efficiency power supply developed for implementation under low-voltage and high-current conditions for sintering applications such as the Spark Plasma Sintering (SPS) and so on. The proposed system consists of four 2,500-A units of the power supply connected in parallel. The output voltage of the proposed system is very low because load resistance is usually very small in SPS applications. Therefore, on the output side, many circuit components are connected in parallel. Especially, in the prototype circuit, many schottky barrier diodes are connected in parallel. As a result, equivalent parasitic capacitance of them could not be ignored from the view point of surge voltage. First, the circuit configuration and the control principle for the proposed low-voltage, high-current power supply are described. Second, the influence of the parasitic capacitance of them and parasitic inductances of each snubber component are clarified by theoretical discussion and simulations. Next, the prototype circuit demonstrates that each individual circuit yields a balanced output. Moreover, temperature of each component is measured during long time operation of the prototype circuit. Finally, it is clarified that experimental results of the surge voltage on the schottky barrier diode are correspond to the theoretical discussion by experiments.