共查询到18条相似文献,搜索用时 62 毫秒
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随着高性能薄板合金的广泛应用,基于实时能量控制波形弧焊技术的发展,对弧焊电源动特性提出了更高的要求.通过对移相全桥弧焊逆变电源的分析,可知移相全桥主电路本质上可等效为Buck模型,利用电路理论推导出小信号模型等效电路的电流传递函数,结合弧焊电源具体特点并进行简化,运用自动控制原理知识分析了弧焊逆变电源的动特性影响因素,并对基于峰值电流反馈的斜坡补偿方法进行具体设计分析,得出了基于峰值电流反馈弧焊逆变电源的动特性与输出回路电抗大小无关的结论.结果表明,仿真和实际电路试验结果均表明分析过程的正确性. 相似文献
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全桥零压零流脉宽调制变换器在全桥零电压脉宽调制变换器中增加一隔直电容,使原边电流在箝位续流时段很快的衰减到零并保持,固定臂的功率器悠扬是零电流开关,移相臂的功率器件是零电压开关。这关,这样,一方面使具有关断拖尾电流特性的IGBT可以很容易的用到全桥软开头变换器中,另一方面大大减少了变换器的附加环路能量,同时具有小的占空比损失,低的副边寄生振荡和宽的软开关切换的负负载范围等优点。最后,采用上述研究成果研制了一台10kW级采用FB-ZVZCS-PWM变换器的软开关弧焊逆变电源样机,温升试验表明,研制的软开关焊机的温升比同类型的硬开关焊机的温升低近20℃,大大减少了焊机的开关损耗,同时,由于焊机的功率元件是零开关,大大减少了器件的电压,电流应力,使弧焊逆变电源的可靠性得以大幅度提高。 相似文献
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研制的谐振式软开关弧焊逆变电源,主电路采用新型LCL结构,控制系统选用恒频移相调脉宽控制方案。介绍了此种弧焊电源的主电路原理,对其工作过程进行了分析。通过仿真及试验对比得出:新型LCL主电路能充分地利用变压器漏感,并能消除占空比丢失;还介绍了系统基本结构、电路及其工作原理,主要包括UC3875电路设置、电弧电压电流反馈电路、IGBT驱动电路;对研制的电源进行了调试及工艺试验。结果表明,焊机工作稳定,控制电路工作性能稳定可靠,具有良好的抗干扰能力,而且软开关范围宽,比较适合于钨极氩弧焊电源。 相似文献
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软开关技术是解决逆变焊电源可靠性的核心技术。本文提出了一种新的软开关逆变焊电源的设计方案,该方案基本上可实现空载、短路、燃弧全负载范围内的软开关状态。本文分析了超前臂的关断功耗与并联电容之间的关系,串联电容及回路电感对环流期的电流变化的影响。并指出了滞后桥臂零电流关断区域,以及超前臂和滞后臂的零开通条件。在此基础上提出了引入无功电流分量解决空载及轻载时软开关失败问题的方案,以及几个主要谐振参数的设计方法。在实践中采用本方案表明,降低了开关应力及损耗,提高了整机可靠性,降低了弧焊电源的成本。 相似文献
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通过将新型软开关电路拓扑和逆变技术引入CO2孤焊电源,保证电源在全范围内实现软开关,使开关管在零电压下开通和关断。开关损耗、开关应力及电磁干扰得到明显改善。同时,开关管工作在较高的逆变频率,通过微机控制,以软件编程的方式对各控制参数进行优化匹配,获得了较合理的电源动特性和较好的焊接效果。 相似文献
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The full-bridge zero-voltage and zero-current switching inverter, which can adjust the output power by keeping the duty-cycle of lagging arm constant, changing the duty-cycle of leading arm, is a common circuit topology of soft-switching inverter arc welding power supplies. However, the output power still remains a certain value when the duty-cycle of leading arm decreases to zero. The working-mode of soft-switching inverter and the waveforms of major parameters with the condition of duty-cycle of leading arm being zero are studied in this paper. U-I characteristic experiments prove that the minimum output power of soft-switching circuit, which depends on the charged voltage of capacitors in parallel with leading arm, can be decreased by reducing the duty-cycle of lagging arm. By switching working-modes between half-bridge and full-bridge, the output power can swing from zero to the power rating. 相似文献
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在对典型全桥软开关功率变换电路进行研究与分类的基础上,提出并设计分析了采用辅助谐振网络的全负载范围零压零流软开关全桥功率变换电路拓扑.通过采用死区时间自适应调节的移相控制方法,使移相控制的死区时间与受电路能量影响的谐振过程协调配合,实现了超前臂功率器件全负载范围的零压开通和效果良好的近似零压软关断.同时,针对全桥移相功率变换电路滞后臂软开通和软关断在全负载范围难以兼顾的问题,提出了零电压与零电流技术相结合的软开关实现方法,通过多种辅助措施的协调配合,实现了滞后臂功率器件全负载范围的零压开通和零压与零流相结合的软关断. 相似文献
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现有FB-ZVZCS-PWM软开关弧焊逆变电源采用阻断电容衰减原边环流电流所需的时间与占空比有关,占空比很小(电源输出电压很低)时滞后臂难以实现零电流开关。采用原边辅助变压器衰减原边环流电流所需的时间不受占空比影响,而与原边峰值电流成正比。文中介绍了采用原边辅助变压器、有限双极性控制的新型FB-ZVZCS-PWM软开关弧焊逆变电源实现超前臂零电压开关和滞后臂零电流开关的工作原理。计算机仿真和试验结果表明,根据最大峰值电流值设计适当的辅助变压器变比,可以在各种负载条件下实现软开关。 相似文献
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Controlling the output power of soft switching arc welding inverter by two-stage continuous PWM method 下载免费PDF全文
The full bridge zero voltage zero current switching( FB-ZVZCS) , which could adjust the output power by keeping the duty ratio of lagging leg constant and changing the duty ratio of leading leg, was a common circuit of soft switching arc welding inverter power source. However, when the duty ratio of leading leg was reduced to zero, the output power stayed the constant value instead of becoming zero. The working status and waveforms of some major parameters were studied in this paper while the duty ratio of leading leg was zero. It was concluded that the minimum output power of soft switching inverter was related to the charging voltage of parallel capacitors, and the output power also could be reduced by reducing the duty ratio of lagging leg. A novel two-stage continuous PWM control method that could switch working-mode between full bridge and half bridge was put forward in this paper. This kind of control method could further reduce the output power of soft switching inverter in order to meet the requirement of low heat input of sheet metal welding. 相似文献
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