【作者】 闫璋；

【导师】 黄鹏飞；

【作者基本信息】 北京工业大学 ， 机械电子工程， 2008， 硕士

【摘要】 逆变弧焊电源技术日趋成熟,但是研制大功率、小体积、高性能的弧焊电源仍是人们不断努力追求的目标。三电平变换器在电力电子直流变换器中的应用越来越广泛,已成为解决小体积、大功率变换器的一个重要方法。三电平直流变换器的首要目的是为了降低开关管的电压应力,同时减小输出滤波电感的值,从而提高工作频率,减小体积。随着软开关技术的飞速发展,结合软开关技术的三电平变换器已成为研究的热点问题。数字电源具有控制灵活、可移植性强、升级方便等特点,随着大规模集成电路和数字信号处理器(DSP)技术的发展,逆变弧焊电源逐渐由模拟控制转向数字控制。本文重点研究三电平逆变弧焊电源拓扑结构及数字控制技术。针对弧焊电源的特点,设计了三电平弧焊电源主功率系统并分析了工作原理,该系统一定程度上实现了软开关技术,降低了开关管IGBT的电压应力和热损耗,为提高电源的工作频率打下基础;设计了基于PIC2020芯片的全数字控制系统,不仅简化了系统的硬件结构,提高系统性能,还可以实现系统的优化控制;采用变参数模糊PI控制方法,根据反馈信号在线实时调节PI参数,使系统在不同负载条件下都具有较佳的响应性能。本文完成了一台基于模糊控制的三电平数字逆变弧焊电源,改善了弧焊电源的动态响应性能,降低了开关管的电压应力和热损耗,提高了工作频率和精度。更多还原

【Abstract】 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.更多还原