Research on the New Soft-switch Arc-welding Inverter Power-supply
|School||West China University|
|Course||Power Electronics and Power Drives|
|Keywords||Arc-welding inverter power-supply Soft-switching DSP Fuzzy Neural networks Intelligent control|
Arc-welding inverter power-supply is the complex power electronic devices, which is the combination of the Electric and Electronic, is one of the main electronic welding research area. This article based on the TMS320LF2407A DSP chip hardware platform ,with the Soft-switch technology and Fuzzy Neural Network control(FNNC) technology, designed a new type of the intelligent-controlling Soft-switch Arc-welding power supply.Firstly, this paper analysised and studied the Soft-switching inverter circuit, established a phase-shifting controlling full-bridge zero-voltage zero-current inverter circuit simulation model ,carry on the computer simulation with Orcad Pspice software,educed the ZVZC switch wave-form, certified the selected inverter circuit. This circuit improved the power-supply output characteristics, efficiency,stability and reliability.Welding technology is a multi-input, multi-output, non-linear system, with the uncertained character of the welding process parameters, so it is difficult to establish accurate mathematical model. In this paper the author proposed that it applied the Fuzzy Neural Network control (FNNC) technology to the Arc-welding power-supply control systems, analysised and deduced the process control model of the arc welding, constructed the FNN constant-current control system, execute off-line study which is based on the FNN model, meanwile, only do positive vague terms on the training-after network , useing momentum term BP algorithm , modifications of the duty cycle was utilized to achieve constant current output of the inverter, when this trained network was used in on-line control. Thereby it is better to use FNN rather than conventional PID on the non-linear systens, improved generalization and self-adaption, real-time ability of network control system. Finaly , completed algorithm simulation on intelligent control useing Matlab.DSP (Digital Signal Processing), a good researching platform was built for useing intelligent control algorithm in digital control.At last,the paper designed the Arc-welding inverter power-supply hardware and software systems in the core of TMS320LF2407A. Its hardware system completed power transformation,welding current, voltage sampling, the PWM drive and magnify to the main power IGBT device, human-computer interaction, and so on. In addition, TMS320LF2407A Demo board provided PWM drive pulse for the PS-FB-ZVZCS circuit, and established the formulation between the duty cycle and the output current diversify, make the output PWM pulse frequency, phase shift and dead time more flexible and easyer-modify by software programming.Finally, It made a brief summary for this paper, proposaled the further improve work to this Arc-welding inverter power-supply design, which is the basement of more deeper study on the Arc-welding power-supply digital control system for the future.