Digital Inverter Arc Welding Power Source Controller Design And Research

Since the invention of arc-welding in the end of the19th century, welding equipments have been developing with the development of science and technology. In recent years, invert arc welding power supply is favored for its smaller size, lighter weight, and higher energy efficiency, and gradually becomes mainstream of the market. On the other side, the digital wave in recent years also influences the field of arc welding power supply, which leads to digitally controlled invert arc welding power source. At present, digitalization has become trend because of the consistency, stability, and flexibility of digital systems. This article follows the trend to do some research on digital controller of invert arc welding power supply.At first, we analyze and discuss the structure of invert arc welding power supply from the system angle. We design the block diagram of the whole power system, and determinate general design schemes of each module of the controller. The controller, which is centered on Micro Controller Unit (MCU), samples signals, does computation with sampled values, and finally outputs Pulse-Width Modulation (PWM) signal of appropriate width according to the computation results. Furthermore, to meet needs of operation and security, auxiliary functions like keyboard, displaying and protection circuits are also designed.Detailed design is introduced from two angles:hardware and software. Core circuits like MCU and its peripheral circuits, signal sampling and conditioning circuits are mainly introduced. These circuits are key parts of feedback loop, whose performance determines the performance of the system, so a lot of problems should be considered when we design. The article mainly analyzes and discusses the anti-interference problem.Introduction on software part is centered on the main flowchart. Analyses and designs of MCU initialization, control algorithm and generation of PWM driving signal are successively introduced.In the end, some problems that we met when debugging are described and analysed, and finally resolved.The process of realizing the digital controller of invert arc welding power supply is a process of trial, and in the meanwhile, provides a favorable platform to do deeper research on arc welding power supply. Research on other external characteristics, new control algorithms and new functions becomes more convenient.