| Abstract |
A LCsCp resonant converter is the chosen topology for the Electrical Discharge Machining power
supply, which has been designed to the purpose to develop small size EDM systems. The switching
frequency is tuned at the natural resonant frequency where the converter tends to act as a current
source. In this way, two effects are achieved: 1) the necessary over-voltage is generated, first to ionize
the dielectric and then to establish the electric discharge and 2) a constant current is supplied during
the machining of the workpiece, providing the circuit with inherent protection under short circuit
conditions. The proposed control achieves an optimum and stable operation using tap water as
dielectric fluid preventing the generation of undesired impulses and keeping the distance between the
electrode and the workpiece within the optimum stable range. The EDM impulse generator has been
validated to perform operations in a nuclear power plant application. A comparative analysis with
other alternative technologies, such as Metal Disintegration Machining and abrasive wheel,
demonstrate that the proposed EDM system achieves higher controllability and tighter tolerance in a
practical cutting process. |
