Improved performance of a plasma cutting machine using a half-bridge dc/dc converter

This paper presents the design and construction of a plasma cutting machine by using a half-bridge dc/dc converter for negative direct current power supply and initial exciting arc by a high voltage high frequency circuit. When the gas passes a torch electrode, it will explode to be plasma arc and transfer to the work piece. The unique research work proposes the high voltage high frequency excitation on all of wide range for cutting metal. This process has been designed for an output power of plasma cutting machine at 2 kW by employing isolate gate bipolar transistors (IGBTs) as switches. The switching frequency is 20 kHz. The plasma cutting machine can cut 1 mm thickness of steel. When compared with a linear transformer plasma cutting machine, Super Air Plasma at 2.2 kW rated, the designed plasma cutting machine has an efficiency quite similar. In addition, the plasma cutting machine is small, light, and compatible. It has also a power and pressure less than the other one.