Design and Control of Pulsed Voltage Supply for Electric Discharge Machining

Electrical Discharge Machining (EDM) is a manufacturing process in which erosion takes place due to sparking between a workpiece and a tool electrode. The EDM circuit consists of DC-DC converters, the EDM load and an interfacing circuit to regulate the machining. The DC-DC converter topologies are modified to suit requirements of the EDM load. Such modifications along with the nature of load and the interfacing circuit, give rise to issues specific to the EDM power supplies. For a particular topology with two DC-DC converters, such issues in modelling and control of the converters are addressed in this work. A new methodology to determine sizing of passive components is discussed. Pulsed current reference scheme is also illustrated, which can improve input to the EDM load efficiency by more than 30%.