Based On Dsp + Mcu Digital Inverter Welding Power Supply System

The development of welding mechanization, automation and the widely application of welding robots has raised an ever-increasing requirement for welding processing property and intellectualized&laticing welding equipment. To meet these requirements, it is essential to research advanced welding equipment and advanced control algorithm for welding processing propert. So the research presented here is concentrated on digital control of welding inverter, aiming at enhancing control precision and flexibility.Firstly, the control principle, characteristics and chip selection of DSP are introduced in the paper. The paper focuses on component part and control principle of digital welding power based on DSP and single chip MCU. Main circuit, control circuit, digital pulse width modulation (DPWM) circuit, drive circuit and wire feeding circuit are respectively analyzed. Furthermore, the software and hardware aspects are also addressed.The main circuit is made up of rectifier, filter, high-frenquency transformer, output reactor, and.full-bridge.inverter, where.4 IGBT are adopted. The key points and parameters of the design are discussed in detail. At the same time, in order to obtain accurate and real-time control,the paper designed a two-processor control system based on TMS320F240 and 80C196KC. TMS320F240 is used to sample welding process parameters, real-time control algorithm. 80C196KC is used to accomplish man-machine interaction, including keyboard, display and communication. Liquid crystal display is adopted as man-machine interface. The key of this system is the communication between DSP and MCU, and serial communication is adopted.Based on the study of the digital pulse width modulation (PWM) mechanism, the digital PWM chip is proposed in the research presented here. It is implemented by very high-speed integrated circuit hardware description language (VHDL) and complex program logic device (CPLD) is a carrier according to the counter principle. The interface is simplified, and stability and security is improved.Reliability and anti-jamming are considered in main circuit and control circuit. System software, which is made of modular subroutines, is very efficient for limiting noise and improving system response-speed.The circumstance of simulation is necessary for designing DSP system and CPLD. The paper illuminates DSP developing circumstance CCS2000 and developing tool XDS 510, MAX+PLUS II and Programming CPLD in detail.Corresponding data and waveforms are recorded, and problems occurred in experiment are investigated. The experiment results verify that the inverter power source has rapid response-speed, high reliability, a strong ability of anti-jamming and good human-computer interface.At last, some advices on future research of the welding power are given, and they will make a profound ground for tomorrow's research of digital welding power...