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脉冲电流波形对Tandem双丝MIG焊力学性能影响 被引量:2
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作者 薛家祥 林方略 +1 位作者 金礼 胡昱 《焊接学报》 EI CAS CSCD 北大核心 2019年第12期6-10,I0001,共6页
双丝脉冲MIG焊作为高效化的不锈钢焊接方法,是目前焊接行业研发的热点之一,但是如何选择和调节双丝MIG焊的电流波形参数依旧是一个难点.为了优化不锈钢焊接的焊接方法,提高焊接效率,文中以双相不锈钢为焊接工件,通过电流波形参数对比试... 双丝脉冲MIG焊作为高效化的不锈钢焊接方法,是目前焊接行业研发的热点之一,但是如何选择和调节双丝MIG焊的电流波形参数依旧是一个难点.为了优化不锈钢焊接的焊接方法,提高焊接效率,文中以双相不锈钢为焊接工件,通过电流波形参数对比试验,研究了双丝梯形波双脉冲焊,双丝矩形波双脉冲焊以及双丝单脉冲焊对焊接质量的影响.结果表明,在相同热输入的条件下,双丝梯形波双脉冲焊焊接稳定性好于双丝矩形波双脉冲焊和双丝单脉冲焊,且前者的焊接成形质量更高,可看到更多的鱼鳞纹,同时使不锈钢接头的的拉伸强度和硬度以及韧性显著提高. 展开更多
关键词 脉冲MIG焊 晶粒细化 拉伸强度 脉冲电流波形调制
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3mm稳频脉冲雪崩管振荡器设计 被引量:3
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作者 陈会 熊文毅 甘体国 《微波学报》 CSCD 北大核心 2005年第6期54-57,共4页
介绍一种3mm 波脉冲雪崩管振荡器,采用顶部斜率可调的脉冲电流给雪崩管(IMPATT Diode)供电, 应用高 Q 腔谐振稳频,具有振荡频率高,输出功率大,频率稳定性好等优点。
关键词 雪崩管振荡器 高Q稳频腔 脉冲电流调制
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干涉测距系统中的光程定位 被引量:1
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作者 洪海涛 叶声华 《光学精密工程》 EI CAS CSCD 1999年第1期110-115,共6页
提出一个由定位干涉仪和测量干涉仪两部分组成的光纤干涉距离测量系统,并采用标准长度光纤实现量程倍增以增大测量范围。文中重点讨论了用准单色光源脉冲电流调制干涉实现光程定位的方法及其精度,通过理论分析和仿真实验可知,定位重... 提出一个由定位干涉仪和测量干涉仪两部分组成的光纤干涉距离测量系统,并采用标准长度光纤实现量程倍增以增大测量范围。文中重点讨论了用准单色光源脉冲电流调制干涉实现光程定位的方法及其精度,通过理论分析和仿真实验可知,定位重复性误差优于±1μm。 展开更多
关键词 绝对测距 光程定位 脉冲电流调制 干涉仪
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Research and realization of PWM drive control digitalization for the full digital welding power supply 被引量:1
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作者 段彬 孙同景 +2 位作者 李振华 梅高青 张光先 《China Welding》 EI CAS 2009年第4期76-80,共5页
Pulse width modulation ( PWM) drive control digitalization is the key for the full digital invert power supply. New ideas are proposed, which are based on field programmable gate array ( FPGA ). First, digital PWM... Pulse width modulation ( PWM) drive control digitalization is the key for the full digital invert power supply. New ideas are proposed, which are based on field programmable gate array ( FPGA ). First, digital PWM principles are discussed. The primary and secondary current characteristics are analyzed when the transformer is in both normal and magnetic bias conditions. Second, two digitalization methods are put forward after the research on PWM adjustment principles, which are based on the primary current feedback. Though the two methods could restrain magnetic bias, their realization is difficult. A new method is researched on double close-loops to overcome the above shortcomings, which uses the secondary current as the feedback signal and the primary current as the protection signal. Finally, the secondary current control made is discussed and realized. Welding experimental results show that the method has strong flexibility and adaptability, which can be used to realize the full digital welding power supply. 展开更多
关键词 full digital welding power supply primary current feedback secondary current feedback field programmable gate array
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Power Quality Improvement Using Grid Side Converter of Wind Energy Conversion System
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作者 Mohamed Machmoum Mohamed Boutoubat Lakhdar Mokrani 《Journal of Energy and Power Engineering》 2013年第4期752-759,共8页
This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The propo... This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM (pulse width modulation) converter. The RSC (rotor side converter) is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC (grid side converter) is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC (point of common coupling) and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved. 展开更多
关键词 Variable speed DFIG MPPT wind energy power quality active filtering GSC.
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