Current source LCC resonant converter for an EDM power supply

Abstract

In this paper, the design of a low size power supply prototype for electrical discharge machining is presented. The system is a DC to DC LCC resonant converter whose 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, first to ionize the dielectric and then to establish the electric arc is generated, and (2) a constant current is supplied during the erosion of the workpiece, providing the circuit with inherent protection under short circuit conditions. The output voltage is intended to be adjusted by an external system that controls the arc distance.