Research On High And Low Voltage Compound Inverter Pulse Power Supply For Dressing Of Metal Based SuperhardAbrasive Wheel

With the development of society,the demand for hard and brittle materials in various fields is increasing gradually.Hard and brittle materials have the advantages of high thermal stability and high hardness.For the processing of hard and brittle materials,in order to achieve sufficient surface accuracy and shape accuracy,the main method at this stage is to use a small grain size grinding wheel for grinding.Metal-based grinding wheel is widely used in the processing of hard and brittle materials due to its high strength and good thermal conductivity.This paper mainly studies a special power supply for EDM dressing of metal-based grinding wheel.According to the literature research,there are few special pulse power supply for EDM in the process of-metal based wheel dressing.Because of the existence of abrasive particles in the process of metal-based wheel dressing,especially when the particle size is large,the discharge rate of EDM will be reduced.Based on this,the high-low voltage composite scheme is adopted to increase the discharge gap and improve the discharge rate.The discharge energy is mainly provided by a low-voltage pulse power supply,which adopts half-bridge inverter circuit.Half-bridge inverter is a kind of nonresistance power supply,which has high power conversion efficiency and strong anti-imbalance.The power supply drives the servo motor through the discharge state detection module to form a closed-loop control.The power supply mainly includes hardware circuit design and software design.The hardware circuit includes the main circuit of the high voltage pulse power supply,the main circuit of the low voltage pulse power supply,the protection circuit,the driving circuit,the discharge state detection circuit,the communication circuit,the control chip and its peripheral circuits.The software part mainly includes FPGA code writing,simulation and upper computer software development.FPGA code includes serial communication,power-off protection,waveform generation,servo control,etc.The upper computer is a human-computer interface,which can input processing parameters in the form of windows and send them to the lower computer through a 485 bus.The high and low voltage composite pulse power supply designed in this paper uses 310 V high voltage,60 V low voltage,1?s-100?s adjustable pulse width,4?s-400?s pulse to pulse adjustable.Through the drilling experiment of titanium alloy material,the wave quality of the power supply achieves the expected effect,and the processing process is stable and reliable.Compared with the traditional power supply,the discharge rate of this high and low voltage composite inverter power supply is obviously improved.