共查询到19条相似文献,搜索用时 167 毫秒
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介绍电除尘用高频电源的组成原理,分析串并联混合谐振变换器并给出实验结果,说明了采用该变换器的技术优越性. 相似文献
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针对传统PID控制的逆变螺柱焊机在负载电流突变时动态特性差、调节时间长的问题,设计了一种高频逆变螺柱焊机,采用DSP作为主控芯片,IGBT全桥拓扑实现高频逆变,高频变压器实现电气隔离和能量传输,并基于电容充电平衡原理,提出了改进的时间最优控制算法,实现了对焊机电压、电流的快速控制,保证了焊机的动态特性和焊接效果。仿真和实验结果表明:所设计的高频逆变螺柱焊机工作性能稳定,焊接效果良好。 相似文献
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<正> 一、前言为了满足各种磁头芯片对金属软磁合金的要求,国内外发展了硬化型坡莫合金。这类合金与坡莫合金相比,具有较高的硬度和电阻率、应力敏感性低、高频导磁率平稳等特点。因此,这类合金的应用范围不限于作各种磁头芯片,正逐渐推广应用到微电机、变压器、电源变换器、高频电 相似文献
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Construction and experimental results of an ozone generator using a ceramic transformer as a high voltage power supply are described. The ceramic transformer has such characteristics that the higher voltage step up ratio and lower input impedance are obtained against higher load impedance. It gives a benefit of current self-regulation. The ozone generator consists of an oscillator, ceramic transformer, four times voltage rectifier and needle-plane electrodes. The corona discharge can be kept constant continuously by the functions of the ceramic transformer with out any current regulating circuits. Thus, the ozone generator has a simple construction. The amount of generated ozone is variable from 0.5 “ppm” to 2.0 “ppm” and can be adjusted by varying the input voltage to the ceramic transformer. This kind of ozone generator is suitable for deodorization and sterilization in home kitchens, and shoe cases and refrigerators. 相似文献
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应用解析信号小波来分析变压器局部放电,提取信号在各尺度的幅值包络、相位和瞬时频率。并将该特征参数用于故障诊断。仿真结果表明:该方法用于变压器局部放电故障诊断中是行之有效的。 相似文献
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Diego Fernando Echeverry Ibarra Héctor Cadavid Ramírez Guillermo Aponte Mayor Alberto Gálvis Castaño 《臭氧:科学与工程》2008,30(3):202-209
Obtaining high-quality cost-effective water, minimizing the public health risk generated by pathogenic elements or disinfection sub-products such as trihalomethane and/or chlorophenol, has made necessary the use of technologies different to chlorination. In this paper, we present the implementation of a high-voltage, high-frequency flyback inverter to generate ozone, and outline the main characteristics and uses of a prototype of water ozonation from a well for a hospital in Colombia. With the prototype, the ozone dose can be adjusted through the duty cycle modulation; switching was done with a Mosfet and the voltage signal was increased with a ferrite technology transformer. The source is characterized by its simplicity, good performance and low cost. 相似文献
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微米铝粉在声场中的振荡燃烧特性 总被引:2,自引:0,他引:2
为了解声场中铝粉的燃烧特性,建立了甲烷平面燃烧器,利用外置喇叭产生振荡,进行了微米级铝粉的燃烧实验。研究了铝粉在不同振荡频率下的分布燃烧响应特性及粒径分别为10、20、30μm的3种铝粉颗粒的燃烧特性和产物的阻尼特性。结果表明,振荡频率不同时,铝粉燃烧对振荡压强的增益作用不同,粒径为20μm铝粉燃烧,在振荡频率200Hz和300Hz时增益作用明显。铝粉粒度越大,分布燃烧增益越大。粒径为10μm铝粉对燃烧器高频振荡阻尼最大。随着铝粉粒度增加,燃烧产物颗粒对高频压强振荡的阻尼减小。 相似文献
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高频脉冲电场参数对水滴极化变形的影响 总被引:4,自引:2,他引:2
在理论分析基础上进行显微实验,得到了高压高频脉冲电场参数对水滴极化变形的影响规律。结果表明,随电场强度的增加,水滴的变形度近似呈抛物线形增大,水滴的极化弛豫时间降低,极化电荷的迁移速度增加,水滴最大变形度所对应的电场频率增大。电场频率过低时,油水乳状液的电容较大,极化电压过小,极化程度较低;电场频率偏离水滴固有频率越多,水滴的振荡幅度及共振效应越差,水滴的变形受到抑制。随占空比的增加,作用于水滴的电场能随之增加,水滴变形度增加;占空比过大,部分电场能经油相发生泄漏,水滴变形度小幅降低。研究发现,高压高频脉冲电场作用下,各电场参数间的交互作用对水滴极化变形的影响不可忽略。上述研究成果为高压高频脉冲静电破乳机理的深入探讨奠定了基础。 相似文献
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Cement mortar can be regarded as a composite consisting of the cement paste, fine aggregate, and the interfacial transition zone (ITZ). In this paper, the formation and development of the ITZ of polymer-modified mortar (PMM) was studied by alternating current impedance spectroscopy (ACIS). The test results showed that the AC impedance spectra of the PMMs had the following characteristics: (1) the AC impedance spectra of the fresh PMMs were almost parallel to the imaginary axis; (2) The AC impedance spectra of the hardened PMMs showed a high-frequency part not connected to the intermediate frequency part. This characteristic was maintained over a rather long period, and then obvious changes appeared in the AC impedance spectra. The age at which the impedance spectra of the mortars changed appeared to shorten with an increase of the sand volume fractions (SVFs). These characteristics of the AC impedance spectra of the PMMs were related to the close contact, the packing, and the formation of a mechanically rigid film of the polymer particles. 相似文献
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高压/高频脉冲交流电场中W/O型乳化液的静电聚结特性研究 总被引:1,自引:0,他引:1
采用矩形流道连续流动实验装置,对W/O型乳化液施加矩形波高压/高频脉冲交流电,以分散相水颗粒体积平均粒径为主要技术指标,研究了电压幅值、脉宽比、脉冲频率等电场参数对不同含水率乳化液静电聚结特性及电源功率的影响.结果表明,电压幅值是影响聚结效果的主要因素,水颗粒粒径随电压的升高而增大;脉宽比对聚结效果和功率的影响较小;脉... 相似文献
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汽车隔音垫用聚氨酯软质高回弹泡沫的吸音性能研究 总被引:1,自引:0,他引:1
通过驻波管法测试不同隔音垫聚氨酯软质高回弹泡沫的吸声系数,结合显微镜对泡沫的力学特性和形态进行观察和分析。研究结果表明,泡沫在低频区的吸声系数随厚度的增加而提高,而在高频区则有所减弱;泡沫的吸声系数随密度增加而提高;泡孔形态对泡沫的吸声性能有显著影响,细密而均一的泡孔有利于声能的吸收;不同异氰酸酯由于反应性和结构上的差异,泡沫也表现出不同的吸声特性;高压发泡生产的泡沫峰值吸声频率稍向高频区移动,复合乙烯–醋酸乙烯共聚弹性体(EVA)后泡沫的峰值吸声频率稍向低频区移动。 相似文献
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以某聚乙烯生产装置熔融泵变频器的更新及应用为例,阐述了熔融泵变频器的技术参数和性能要求,结合更新所选变频器的控制方式和技术特点,介绍了熔融泵变频器更新调试的操作步骤和要点。 相似文献