Adaptive Voltage Position Control for Pulse Power Supply in Electrical Discharge Machining

In order to improve the power efficiency and dynamic response of the pulse power supply in electrical discharge machining (EDM), an adaptive voltage position control with a flexible ability of the discharge energy adjustment, dedicating to the pulse power supply in EDM, is proposed in this paper. By introducing the sum of the gap voltage and current as a control object, the voltage mode and the current mode control can be switched freely, which fits the discharge gap characteristics. Based on the analysis of the dynamic response and the steady state of the converter, the design of key power components and control parameters are given. As a result, a fast switch between the voltage control and current control, a high dynamic response on the gap state changing, and a well-discharge current as well as a discharge energy control in a discharge period can be achieved, which means a high power efficiency, a high machining consistency, and a high machining speed for the pulse power supply.