共查询到20条相似文献,搜索用时 15 毫秒
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Yuan Chen Westergard L. Mojarradi M.M. Johnson T.W. Cozy R.S. Billman C. Burke G.R. Kolawa E.A. 《Device and Materials Reliability, IEEE Transactions on》2006,6(2):146-153
A design for reliability methodology has been developed for electronics for low-temperature applications. A hot carrier aging (HCA) lifetime projection model is proposed to take into account the HCA impact on technology, analysis of parametric degradation versus critical circuit path degradation, transistor bias profile, transistor substrate current profile, and operating temperature profile. The most applicable transistor size can be determined in order to meet the reliability requirements of the electronics operating under low temperatures. This methodology and approach can also be applied to other transistor-level failure and/or degradation mechanisms for applications with varying temperature ranges. 相似文献
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《Power Delivery, IEEE Transactions on》1998,13(1):73-77
IEEE Standard 1344, Synchrophasors for Power Systems, was completed in 1995. It sets parameters required to ensure that phasor measurement will be made and communicated in a consistent manner. It specifies requirements for the timing signal used for phasor synchronization and the time code needed for input to a measurement unit. GPS is the recommended time source and IRIG-B is the basic format used for time communication. The standard requires correlating phasors computed from unsynchronized and synchronized sampling to a common basis. Timetagging accurately and consistently is essential for wide area comparison of phase. The standard specifies information exchange and control message formats. These include data output, configuration, and command messages. It includes 7 annexes that discuss the concepts covered in the body of the standard 相似文献
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分析了GIS断路器故障原因,介绍了检验过程与充气检查、监督情况,并提供一些可借鉴的成功经验。 相似文献
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介绍了全寿命周期成本管理理念及110kV GIS远景间隔可采取的预留方式,并对变电站110 kV GIS远景间隔的各种预留方式进行分析比较。 相似文献
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针对中国电力科学研究院开发的《PSD-SCCPC电力系统短路电流程序》中基于潮流和基于网络的两种短路电流计算模式计算结果存在一定差异的情况,从计算结果真实性、可比性、准确性和对电网的指导作用等方面分析、比较两种计算模式的适用环境。得出结论:基于潮流的计算模式,其计算结果能真实反映实际系统运行情况,适用于电网规划中的网架校验;基于网络的计算模式具有较强的可比性,适用于运行方式的安排和校验。最后提出开展基于网络计算模式修正系数取值研究工作的建议。 相似文献
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S. V. Kudryashov 《Russian Electrical Engineering》2008,79(4):192-195
A method for calculating iron loss in switched-reluctance motors is given. It is necessary to separate the elements of the magnetic system of an electric motor in order to calculate the magnetic flux density according to the turning angle of the rotor. Then, calculations of losses due to hysteresis and eddy current are conducted. The described method can be applied for the verification and design of inductor motors. 相似文献
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Since 1987, many electric utilities throughout North America have been actively promoting demand-side management (DSM), the attempt to conserve fuels and postpone costly generating capacity increases by encouraging customers to use more efficient electrical equipment, including motors. One popular DSM program has been utility payment of cash rebates to purchasers of more efficient motors. Today, such payments face extinction in a rapidly changing utility economic climate based on deregulation. How rebates originated, the basis for such payments, how successful rebate programs have been, and what the future holds for them are the subjects of this paper 相似文献
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介绍了1次作为真空容器的凝汽器的水位测量偏差缺陷消除的过程.由于常规的消缺办法无法奏效,通过观察总结出隐含规律,并依据理论分析和公式计算找出故障范围和原因,在不影响机组安全运行的基础上消除了缺陷. 相似文献
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接地网腐蚀分块诊断的混合优化算法 总被引:8,自引:0,他引:8
为提高接地网腐蚀诊断的速度和精度,提出一种接地网分块诊断方法,采用节点撕裂的方法,将接地网自动撕裂成若干个子网络和一组自由支路,建立反映子网络等效不定节点导纳与可及节点电压和撕裂点广义节点电流之间非线性关系的多目标优化模型。求解模型的算法结合了粒子群算法和最小二乘法的优点,并提出双层粒子群的思想,充分利用粒子群算法的快速收敛性和全局寻优能力得到符合优化模型的有效解,然后利用最小二乘法确定最优解。对110 kV 蒲城变电站接地网的仿真测试验证了算法的有效性。 相似文献
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外高桥发电有限责任公司2号机组炉水采用氢氧化钠处理前期,炉水氢电导率和氯离子含量时有超标现象.分析了造成炉水氢电导率和炉水氯离子含量超标的主要原因,通过调整凝结水精处理运行方式,使炉水的氯离子稳定、可控,解决了磷酸盐处理工况时氯离子易出现的超标现象,防止了氯离子对炉管的腐蚀隐患,取得了良好的经济效益. 相似文献