Research On Pneumatic System Of Plasma Cutting Power Supply System

Plasma cutting power supply of gas/water system involves many aspects including physics characteristic of plasma arc,power electronics,motor control,communication protocol,the electromagnetic device, cutting technology and so on.Study on high performance,high efficiency plasma cutting power supply of gas/water system is very important to improve the cutting quality and efficiency.Plasma cutting power supply is composed of main circuit、gas/water control box、ignition console box(high frequency ignition circuit)、off-valve assembly.This paper mainly introduces the structure and control principle of the gas/water system,and analyzes the gas supply in detail from two aspects of hardware/software,the solenoid valve drive circuit and corresponding control circuit.I improve and optimize“Hypertherm”plasma cutting machine solenoid valve control circuit,and apply for a patent : Fluid valve design algorithm with conditions. DSP(TMS320F28335) is used as the central control unit to realize the control of the following modules:rotary encoder、 dial switch control module 、 CAN/I2C/SPI communication protocol module. CPLD(LC4256V) is used as an auxiliary control chip to realize the temporal order judgment,backup program function.Plasma cutting power supply system may encounter various interferences in the actual operation of gas/water system,this paper make corresponding improvements in the two aspects of the hardware/software.In the schematic design、PCB production and relating software process,I have taken corresponding anti-interference measures including:filtering、isolation and grounding、shielding technology and so on.In debugging stage, I analyze and solve the gas/water system debugging problems,and describe the test waveform of each module in detail.The SPI/CAN test waveforms display module communication run well.Finally,I summarize this article and the plasma cutting power supply system is prospected.