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1.
通信开关电源技术的进展   总被引:1,自引:0,他引:1  
简要回顾了 2 0世纪通信开关电源技术的进展历程和取得的成就 ,高功率密度、高效率、高性能、高可靠性仍然是今后开关电源的发展方向。提出了二十一世纪我国应注意开发的八项电源技术  相似文献   

2.
卷首语     
《电源世界》2006,(3):I0001-I0001
现代通信、电力改造、绿色照明、空间技术、能源转换、信息技术等进步极大地带动高频开关电源的普及和发展。随着大规模集成电路的成长介入,高频开关电源与之相适应的技术层出不穷。高频开关电源的变脸目前主要集中在数字化控制及磁集成技术方面,同时也伴随新型电路拓扑、建模仿真。这些值得大家关注,也是研究热点。  相似文献   

3.
通信高频开关电源系统普遍采用软启动技术,以提高功率密度、降低损耗、提高系统的效率指标,这一技术被视为高端高频开关电源的特征。软启动即零电压变换(ZVT)、零电流变换(ZCT)技术,是系统在交流电波形的0 V电压点启动,在交流电波形的0 A电流点关断,从而彻底避免大功率通信开关电源系统在开、关时产生的巨大冲击和谐波,是目前不污染电网和节能降耗的高端技术,是安全生产的技术保障。  相似文献   

4.
开关电源体积小、功耗少,在电子计算机、录相机及通讯设备中广泛应用。随着集成电路技术的发展,各种电子仪器设备体积都显著减小,开关电源的小形化就成了电子仪器小型化的关键问题。同时,电子仪器的发展,扩大了对开关电源的需求。根据1989年市场销售情况,开关电源的应用分布情况如下: 计算机40% 办公自动化设备22% 工厂自动化控制设备15% 通信设备13.5% 民用设备8% 医疗电子仪器及其它1.5% 以下就开关电源的主要技术动向进行介绍  相似文献   

5.
低压大电流开关电源的设计   总被引:2,自引:0,他引:2  
随着计算机、通信技术的发展,低电压大电流开关电源成为目前一个重要的研究课题。介绍了一种输出电压为3.3V,输出电流为20A的开关电源的设计过程。  相似文献   

6.
《电源技术应用》2013,(7):I0002-I0002
进入21世纪以来,随着开关电源技术的发展和市场需求的驱动,电源领域里开关电源的优势将会越来越明显,缺陷也将逐步得到克服和改善。鉴于此,本期特别安排了开关电源技术专题,跟踪开关电源技术的近况和未来的发展趋势,具体涉及以下几个方面:  相似文献   

7.
高频开关电源技术及应用简述   总被引:2,自引:0,他引:2  
许俊荣 《安徽电力》2003,20(4):27-29
本文在介绍开关电源工作原理的基础上,详细说明了PWM功率变换技术、有源功率因数校正APFC技术及开关电源在电力操作电源和通信电源系统中的具体应用。  相似文献   

8.
正随着近几年电源技术和防雷保护技术的不断发展,变电站的通信电源系统也发生较大变化。智能高频开关电源、免维护蓄电池、浪涌保护器(SFD)等设备在变电站的通信电源系统得到广泛应用。为保证变电站通信电源系统的可靠性和安全性,各级电力通信管理部门对通信电源系统提出了较高的要求。  相似文献   

9.
开关电源处于以电力电子技术为基础的电源技术的核心地位,由于其高效节能可带来巨大经济效益,因而引起社会各方面的重视而得到迅速推广。开关电源高频化、模块化、数字化的实现,将标志着这些技术的成熟,达到了高效率用电和高品质用电相结合本文论述了开关电源的发展及技术趋势。  相似文献   

10.
浅析开关电源的电磁干扰与滤波措施   总被引:1,自引:0,他引:1  
张林 《电气时代》2000,(3):27-29
1.引言 开关电源是综合应用半导体变流技术、电子及电磁技术、自动控制技术等电力电子先进技术的产品。它和线性稳压电源相比,具有功耗小、效率高、体积小、重量轻及稳压范围宽等突出的特点,因而被广泛应用于计算机、外围设备、通信、工业自动控制及家用电器等领域。但开关电源的突出缺点是产生较强的电磁干扰(EMI)。它产生的EMI信号,既占有很宽的频率范围,又有一定的幅度。这些EMI信号经过传导和辐射方式污染电磁环境,对通信设备和电子仪器造成干扰。如果处理不当,开关电源本身就会变成一个干  相似文献   

11.
论微膨胀混凝土筑坝技术   总被引:38,自引:5,他引:33  
微膨胀混凝土筑坝可在一定程度上简化温控,提高建坝速度,如能进一步改进,有可能使混凝土筑坝技术发生较大的改观。本文全面分析了微膨胀混凝土筑坝技术中的问题及对策。分析了氧化镁含量、混凝土温度、室内外差别等对自生体积变形的影响,指出了氧化镁混凝土筑坝的地区差和时间差。文中分析了微膨胀混凝土应用于碾压混凝土重力坝、常态混凝土重力坝和拱坝时的问题和解决途径,指出如仍保持氧化镁掺率不超过5%,可用氧化镁混凝土  相似文献   

12.
The propagation of shock wave pressure in the tunnel is greatly affected by the tunnel structure, shape, material and other factors, and there are great differences in the propagation law of shock wave pressure in different kinds of tunnels. In order to study the propagation law of shock wave pressure in tunnels with different mate-rials, taking the long straight tunnel with the square section as an example, the AUTODYN software is used to simulate the explosion of TNT in the concrete, steel and granite tunnel, and study on the variation law of shock wave pressure in tunnels with different materials. By using dimensional analysis and combined with the results of numerical simulation, a mathematical model of the propagation law of shock wave pressure in the tunnel is established, and the effectiveness of the mathematical model is verified by making the explosion test of the warhead in the reinforce concrete tunnel. The results show that the same mass of TNT explodes in the tunnel with different materials, and the shock wave overpressure peak at the same measuring point is approximate in the near field. However, there is a significant difference in the middle-far fields from the explosion center, the shock wave overpressure peak in the steel tunnel is 20.76% and 34.82% higher than that of the concrete and the granite tunnel respectively, and the shock wave overpressure peak in the concrete tunnel is 24.91% higher than that in the granite tunnel. Through the experimental verification, getting the result that the maximum relative deviation between the measured value and the calculated value of the shock wave overpressure peak is 11.85%. Therefore, it is proved that the mathematical model can be used to predict the shock wave overpressure peak in the tunnel with different materials, and it can provide some reference for the power evaluation of warhead explosion in the tunnel.  相似文献   

13.
基于视频的人群异常事件检测综述   总被引:2,自引:0,他引:2  
随着公共安全问题的日益突出,公共场所人群异常事件的及时发现将有助于相关部门的及时响应和救援,从而降低群众人身伤亡和财产的损失。近年来,在智能监控和安防领域的发展下,基于视频的人群异常事件检测已成为图像处理、机器视觉、机器学习等相关领域的研究热点。概述了基于视频的人群异常事件检测相关研究的概况、研究现状及未来的发展趋势。人群异常事件检测有两个基本问题,一个是基本事件的表示,一个是异常事件检测模型的建立。重点从这两个方面回顾人群异常事件检测技术的发展和常用的处理方法,并对研究难点及未来的发展趋势作了较为详细的分析。  相似文献   

14.
尽管非洲经济发展面临诸多挑战,但增长趋势仍在继续。伴随着各国电力需求的增加,非洲电力基础设施建设充满机遇。非洲水电资源丰富,开发潜力巨大,且80%的可开发水电资源潜能集中在赞比西河、刚果河、尼罗河和尼日尔河四大流域。在“一带一路”倡议下,已有大批中国企业“走出去”投资开发非洲水电项目,推动中非电力基础设施合作。本研究通过大量的数据和资料,总结了四大流域水电资源量与开发程度,对流域内重点已建和规划的水电项目进行了详细介绍。最后,深入分析中国企业目前在非洲水电项目开发中面临的主要问题和挑战,并从战略规划、合作模式、风险防范和人才培养四个方面提出相应建议。  相似文献   

15.
铜、铝导体生产的发展趋向及有关问题的探讨   总被引:4,自引:0,他引:4  
黄崇祺 《电线电缆》2004,(3):3-12,17
本文综合分析了我国铜、铝及它们的合金导体在品种、质量和生产装备方面的现状和国外在该领域的进展及发展趋向,并指出:我国铜、铝导体的年用量已名列世界前茅,但导体的品种少,工艺装备落后。其中铝连铸连轧生产线比铜的更落后,主要差距在计算机监控系统,由此也限制了品种的发展;废铜在导体上的应用,要提高质量关键在于所用废铜原材料的级别、熔炼炉及熔炼工艺;铜杆质量不能满足电缆工业发展的需要,修订电工用铜杆国标或制订行业标准,实行铜杆分等使用已是势在必行;我国电缆工业需要建立真正意义上的从金属材料、镀层、导体结构到绝缘材料特种的电缆厂;行业协会在组织行业内部带有共性问题的科技攻关,与产业界、行业间的协调和科技合作方面应起到更大的作用;应发挥综合优势,加强材料、工艺、产品与设备的联合攻关,实现科技与生产的创新。  相似文献   

16.
One of the most effective energy saving technologies is the improvement of existing heat and mass exchange units. A stream-bubble contact device is designed to enhance the operation efficiency of heat and mass exchange units. The stages of the stream-bubble units that are proposed by the authors for the decarbonization process comprise contact devices with equivalent sizes, whose number is determined by the required performance of a unit. This approach to the structural design eliminates the problems that arise upon the transition from laboratory samples to industrial facilities and makes it possible to design the units of any required performance without a decrease in the effectiveness of mass exchange. To choose the optimal design that provides the maximum effectiveness of the mass-exchange processes in units and their intensification, the change of the mass-transfer coefficient is analyzed with the assumption of a number of parameters. The results of the study of the effect of various structural parameters of a stream-bubble contact device on the mass-transfer coefficient in the liquid phase are given. It is proven that the mass-transfer coefficient increases in the liquid phase, in the first place, with the growth of the level of liquid in the contact element, because the rate of the liquid run-off grows in this case and, consequently, the time of surface renewal is reduced; in the second place, with an increase in the slot diameter in the downpipe, because the jet diameter and, accordingly, their section perimeter and the area of the surface that is immersed in liquid increase; and, in the third place, with an increase in the number of slots in the downpipe, because the area of the surface that is immersed in the liquid of the contact element increases. Thus, in order to increase the mass-transfer coefficient in the liquid phase, it is necessary to design the contact elements with a minimum width and a large number of slots and their increased diameter; in this case, the filling degree of contact elements by the liquid must be maximum.  相似文献   

17.
挤包绝缘高压直流电缆在直流输电工程中应用广泛,但制造与应用中的梯度效应显著影响其直流电气性能。以500 kV交联聚乙烯直流电缆为研究对象,首先,通过仿真计算理想均匀绝缘电缆中的场强分布;然后,计算交联和脱气过程中绝缘层的温度分布,并对电缆绝缘切片取样,测量不同径向位置绝缘的相态结构和直流电气性能;最后,根据实测电导率对电缆绝缘中场强分布进行仿真。结果显示:电缆绝缘在交联和脱气过程中存在温度梯度,绝缘的相态结构和直流电气性能在径向上分布不均匀,绝缘电导率在径向上的梯度分布导致电缆绝缘中场强均呈现出内低外高的分布规律,且最外侧绝缘的场强大于均匀绝缘中的最高场强。  相似文献   

18.
《电机与拖动》课程教学中的创新探讨   总被引:9,自引:0,他引:9  
《电机与拖动》课程是机电一体化专业通用的专业基础课,有很强的理论性、实践性。长期以来,《电机与拖动》课程教学在理论推导、知识连续模式、教学方法和手段、实践环节等方面存在着诸多问题。在多年教学实践的基础上,结合精品课程建设与高职高专教学改革,从教学内容、教学方法、教学手段、实践教学等方面对《电机与拖动》课程的教学创新进行了研究与探讨,提出了改革方案,为同类型精品课程建设提供了借鉴。  相似文献   

19.
随着我国风电行业的快速发展,规模化发展风电对能源转型的推进至关重要。然而,由于风电场所处的复杂环境和高昂的建设运营成本等因素,集群化发展模式下的风电场面临着一系列技术难点和挑战。因此,本文针对集群化发展模式下风电场的建设和运营,重点总结了相关的预测、规划和控制关键技术。具体而言,本文围绕风电场集群的关键技术与研究思路进行了归纳总结。针对风电场集群的特点,包括风资源量化表征与预测技术、多风电场协同优化规划技术以及多风电场控制与运行技术进行了详细探讨。对于每个技术领域,本文分析了当前的研究现状和取得的成果。最后,本文阐明了风电场集群建设和运营关键技术领域的发展趋势,并指出了待解决的技术难点。通过总结这些技术的研究成果为我国风电的规模化、集群化开发提供参考。  相似文献   

20.
Tariff regulation is a fiscal method of managing economic processes with the help of taxes, requiring constant development, which is directly related to the development of the electric power industry and technological progress in general. The relevance of the study is conditioned by the need to find and implement methods for optimising tariff regulation in such an economically important industry as the electric power industry. In this regard, the purpose of the study is to identify problem areas in tariff regulation in the electric power industry, consider and analyse optimisation methods used in other countries, and reveal the positive impact of these methods on the electric power industry and the economy as a whole. The primary method in this study is a system analysis, which was used for a detailed consideration of the subject matter, with the aim of a deeper and more comprehensive understanding of tariff regulation in the electric power industry as a system with many related and interacting elements. This study also applied the following research methods: logical analysis, comparison, synthesis, deduction, and classification. The study presents the results of tariff setting mechanisms in the industry, examines the existing types of regulated prices and tariffs in the consumer electricity market, and considers the state, private, and public levels of tariff regulation in the Russian Federation. The methods of improving and developing tariff regulation in other countries, which have been successfully applied and have already shown a positive result, were also considered. The study materials are of practical value for teachers and students in the field of electric power industry, managers of tariff regulation bodies.  相似文献   

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