Abstract:

At low pressure, cold plasmas are used for a wide range of applications such as coating, flow control, or microelectronics. Currently, this industry requires expensive vacuum systems which consume energy and time, and therefore it is very appealing to develop similar processes at atmospheric pressure. Under this condition, dielectric barrier discharge (DBD) is one of the best ways to obtain a cold plasma. The dielectric barriers naturally limit the current, and then the plasma temperature. Unfortunately, at atmospheric pressure the discharge ignition between the electrodes requires high voltage, which is generally obtained through a step-up transformer. The parasitic elements of this device exclude a smart control for the discharge. In order to overcome this default, we analyze the performance of a transformerless power supply developed with a recently released single-chip high-voltage semiconductor. The circuit uses only two high-voltage switches synthesized by means of the 10 kV SiC MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The design and implementation of the electric converter are presented and validated with experiments carried out on UV excimer DBD lamps. Then, the performances of the 10 kV SiC switches are analyzed and the relevance of this device for DBD applications is discussed.

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