Papers by Keyword: EDM Pulse Power Supply

Abstract: In this paper a kind of architecture for an energy-saving EDM supply composed of three serial stages in the topology and its practical design are discussed. Various special controllers and its assisted circuits are introduced in the each of the three serial stages. The PFC controller UC3854 placed on the front stage provides satisfactory input power factor of the system. The PWM controller UC3875 mounted on the middle stage realize the closed control of the current of the inductance limiting machining current. An embedded controller PIC16F877 on the final stage is chosen to setting such machining variables as peak current, discharge duration and pulse interval. The communication with host PC is also realized by the same embedded controller. The architecture based on model of multi-controller parallel working guarantees capacity of the system real-time process. The prototype of the energy-saving EDM pulse supply using MOSFET power device is developed. A lot of experiments have demonstrated the feasibility and stability of the practical design.

Abstract: The performance and stability of output of electrical discharge machining (EDM) are determined by the output of EDM pulse power supply. In order to resolve disadvantages of conventional pulse power supply, such as undesirable efficiency and low power factor, the prototype design of energy-saving EDM pulse power supply is developed. It is composed of such three stages as a single-phase active power factor correction (PFC) pre-regulator, a full-bridge phase shift zero voltage switching (FB-PS-ZVS) converter based on complex control paralleled of machining current closed-loop and voltage closed-loop at period of spark gap insulation, and a pulse generator based on machining sequence control. The PFC pre-regulator contributes to a great increase to about 0.95 in its power factor. The efficiency of the new system is considerably increased to about 70% due to design of ZVS. The pulse generator contributes to the pulse machining current without a tail. Experiment results demonstrates that the prototype is capable of low electrode wear, high speed, stable machining.

Abstract: Their efficiency and their power factor of conventional independent electrical discharge machining (EDM) pulse power supplies with the current-limiting-resistor circuit is so low that they do not meet the need of advanced EDM technologies. The design of highly efficient EDM pulse power supply based on switching circuit pulse width modulation current closed-loop principle has been initiated. It is composed of such three stages as a single-phase active power factor correction preregulator, a full-bridge phase shift resonant converter based on machining current closed-loop control and a pulse generator based on machining sequence control. Therefore, the efficiency of the new system is considerably increased to about 70%, its weight and size is decreased much. Its power factor is a great deal increased to about 0.95. Experiment results have demonstrated that the highly efficient EDM pulse power supply is capable of low electrode wear, high speed, stable machining.