One-Cycle Control for Pulse Power Generator in Electrical-Discharge-Machining

Due to a short-time gap breakdown in electrical discharge machining (EDM), a high dynamic response and flexible discharge current control ability are required for a pulse power generator. Therefore, a one-cycle control(OCC) of output current for a buck-type EDM pulse power generator is proposed. Considering the inductor current operating state, a full-range OCC current control is presented, and the Taylor expansion method is used for the duty cycle calculation. A duty cycle optimization strategy is proposed for transient states. Based on the small signal modeling, the dynamic response ability of the system is analyzed. The discharge current can switch from many transient states to a steady state in a few switching cycles without a current overshoot, and follow the average current reference well in the steady state.