The Study Of Three-Level Digital Arc Welding Inverter Power Supply

Nowadays the technology of arc welding inverter is gradually being perfect.However, there hasn't stopped to search for a high-power, small volume, highperformance arc welding inverter power supply. Three-lever DC/DC converters arewidely used in power electronics applications, and it is one of the very important waysto increase the voltage and decrease the volume. The main objective to proposethree-level converter is to reduce voltage stress across the power switches, meaningwhile the output filter inductance, so that the volume can be reduced and thefrequency can be increased. With the development of soft switching, it is the studyhotspot that how to combine three-level converter with soft switching. The digitalpower has many merits such as flexible control, high transplantation and convenientupgrading. So, with the development of integrated circuit and signal processingsystem (DSP), the digital control system is replacing the analogue control system ofarc welding inverter gradually.The article studies the topology of three-level arc welding inverter power and thedigital control technology. According to characters of arc welding inverter power, itdesigns topology of the three-level digital arc welding inverter power and analyzes theprinciple. This system has advantages of three-level converter and soft switching;reduces voltage stress and thermal losses of IGBT; improve the frequency. This articledesigns digital control system based on PIC2020. The digital control technique cansimplify the configuration of hardware; advance the system performance and optimizethe control strategy. The system adopts varying parameter fuzzy PI control to adjustparameters according to the feedback to make the system has good responseperformance on condition of different loads.This article finishes a three-level digital arc welding inverter power supply basedon fuzzy control. The system improves dynamic response of arc welding inverterpower; reduces voltage stress and thermal losses of IGBT largely; improves thefrequency and accuracy.