Modeling pulse power generator of Electrical Discharge Machining

Abstract

Electrical Discharge Machining (EDM) is non-conventional manufacturing process that uses electrical energy to shape the material, high voltage as the source for removal, electrons as the medium to transfer the energy and spark erosion as the mechanism that involves in the manufacturing process. A series of stochastic sparks are produced when the gap between electrode and workpiece is very narrow just about 10 to 50 microns. EDM has been introduced to this project due to the capability covering a various type of conducting material such as steel, titanium, super alloys, refractories and aluminum. The selection of EDM pulse power generator is one of the most critical aspects to take into consideration in the manufacturing process. This project focused on the modeling and analysis of pulse power generator of EDM. A model of pulse power generator has been developed by using model-based design tools MATLAB/Simulink. Pulse power generator consists of power supply unit and pulse generator unit. The first section of pulse power generator which is linear power supply has been modeled accordingly. Similarly, the second section of pulse power generator which is the pulse generator, the system has been modeled in order to analyse the pulse profile of EDM. The characteristic of the pulse profile are an open circuit, normal discharge, arc and short circuit condition during the machining process. A model of pulse power generator has been presented and implemented successfully. The phases of the pulses have been discussed thoroughly which are initial phase, ignition phase, discharge phase and ejection phase. The pulse power generator model has been simulated and validated by the experimental results of previous research.