共查询到20条相似文献,搜索用时 31 毫秒
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一些不燃型氟碳化合物具有非常好的绝缘特性,既可以作为蒸发冷却变压器等电气设备的冷却介质,也可以作为绝缘介质,使得蒸发冷却变压器不燃不爆、安全可靠、经济高效、绿色环保、成本适中,适用于某些特定场合的需求。在作为绝缘介质实际运行过程中,氟碳化合物将以气液两相流状态存在。为研究该工况下介质的绝缘性能,本文参考国家标准研制了实验装置,测量了若干种氟碳化合物介质在两相流状态下的工频击穿电压特性。实验采用3mm间隙的板-板电极,得到了不同工作压力下的工频击穿实验数据,以及击穿电压与工作压力的经验公式。实验结果的统计分析显示两相流状态下工频击穿数据很好地服从于威布尔分布和正态分布,通过计算得到了各工作压力点下击穿电压值的概率分布函数,为蒸发冷却变压器绝缘结构的设计提供了参考。 相似文献
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从标准对通断试验容量和电源的要求入手,对额定电流630A以下电气设备通断试验所需的供电电源进行分析,进行不同形式下的电压波动计算和最大试验电流的计算,为煤矿用低压电器试验室建设中试验电源问题的解决提供参考。 相似文献
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特高压交流试验基地的建设 总被引:3,自引:6,他引:3
国家电网公司特高压交流试验基地的建设是我国交流特高压输变电试验示范工程的重要组成部分。为了给我国特高压输电系统工程提供有力的技术支持和服务,介绍了特高压交流试验基地的总体规划、技术要求、主要试验功能和建设中的技术难点。特高压交流试验基地占地14万m2,由220kV电源系统、1km特高压单回试验线段和1km特高压同塔双回试验线段、特高压设备带电考核场、大电流升流装置、电磁环境参数测试场及屏蔽室、环境气候试验室、特高压电晕试验笼以及辅助设施等组成,其中重点就1000kV单回和同塔双回试验线段、特高压设备长期带电考核场、环境气候试验室、电磁环境测量和电晕试验笼的优化设计等进行了讨论。 相似文献
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Hirofumi Maruyama Kensuke Matsuo Masahiro Kozako Masayuki Hikita Kazuo Iida Tokihiro Umemura Yusuke Nakamura Tetsuo Nakamae Teruhiko Maeda Masakazu Higashiyama 《Electrical Engineering in Japan》2019,208(1-2):10-16
It is crucial for cast resin transformer to detect void and delamination existing in the cast resin because these defects reduce insulation performance of cast resin equipment. Furthermore, defects are likely to be mixed in cast resin because of several surface boundaries between resin and conductor. It is considered that detecting partial discharge (PD) is effective to diagnose equipment of power equipment. However, it is reported that withstand lightning impulse voltage test may give influence on AC partial discharge test, especially partial discharge inception voltage. This paper deals with accumulated charge in a void under AC voltage to investigate the effect of the impulse voltage prestress on subsequent AC PD characteristics in cast resin transformer. AC PD characteristics were compared before and after impulse application. In addition, recovery of PD characteristics was measured to investigate charge decay. As a result, the mechanism of prestress effect is revealed and surface charge density is estimated quantitatively in cast resin transformer. 相似文献
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电力电子装置高压阀的电介质试验 总被引:2,自引:0,他引:2
我国的电力发展战略需要大量使用电力电子装置,电网的安全稳定运行要求电力电子装置在投入前必须进行严格的试验。电力电子装置高压阀是电力电子装置的核心部件,也是最脆弱的环节,是试验的重点。为此介绍了大功率电力电子装置阀(SVC阀、TCSC阀、STATCOM阀和HVDC阀等)的电介质试验,包括IEC标准对试验的要求、试验装置、仪器、局部放电测量方法、测量仪器等。以莱阳钢厂晶闸管控制电抗器(TCR)型静止无功补偿(SVC)工程为例介绍了试验方法在实际工程中的具体应用,给出了试验波形。工程应用的结果证明了试验方法的实用性和有效性。 相似文献
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为准确评估硅IGBT和碳化硅MOSFET等高压大功率器件不同电应力及热应力条件下的栅极可靠性,研制了实时测量皮安级栅极漏电流的高温栅偏(high temperature gate bias,HTGB)测试装置。此外,该测试装置具备阈值电压在线监测功能,可以更好地监测被测器件的状态以进行可靠性评估和失效分析。为初步验证测试装置的各项功能和可靠性,运用该测试装置对商用IGBT器件在相同温度应力不同电应力条件下进行分组测试。初步测试结果表明老化初期漏电流逐渐降低,最终漏电流大小与电压应力有良好的正相关性,栅偏电压越大,漏电流越大。该测试装置实现了碳化硅MOSFET器件和硅IGBT器件对高温栅偏的测试需求且适用于各种类型的封装。 相似文献
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高压直流换流站污秽水平预测方法研究 总被引:4,自引:1,他引:4
对换流站站址周边地区气象、工业污染源和输变电设备运行的相关资料进行收集,根据风洞试验得出的绝缘子表面积污模式,利用污染源扩散模式计算站址及周边地区交流盘形绝缘子积污水平。在此基础上,根据国内已有换流站和自然积污站的直、交流积污数据并结合具体情况,选择合适的直交流积污比,由计算出的交流盘形绝缘子污秽水平估算出换流站直流场设备的污秽水平。根据该污秽水平,计算出换流站直流场支柱绝缘子以及不同管径的套管表面的污秽度。根据标准直流支柱绝缘子的人工污秽试验数据和预估算的污秽度,确定直流支柱绝缘子和各类套管的爬电比距。文中提出的方法可用于±500kV、±800kV高压直流换流站污秽水平预测及外绝缘配置。 相似文献
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AC superconducting wire is being developed for such electrical equipment as superconducting transformers and superconducting generators. AC loss reduction is of primary concern in the development of such high-efficiency equipment. In reducing ac losses, it is necessary to develop assessment methods for ac loss in test samples which have shapes similar to the end-product equipment. This paper describes a least-square calculation of ac losses of superconducting wire as a function of frequency and magnetic field strength measured in test coils. Two sample solenoid coils were made to test the influence of different capacities and winding methods on ac losses in ac superconducting coils with rated capacities of 500 kVA and 20 kVA, and impregnated (epoxy resin) and nonimpregnated windings. The ac losses in the superconducting coils were measured by a calorimetric method using the evaporating rates of liquid helium. Estimated ac losses in the superconducting wire of the two coils were compared with Joule losses of copper conductors at ambient temperature. As a result of this comparison, a low-loss ac superconducting wire winding can be made for electrical equipment rather than employing conventional copper winding when used under low magnetic fields under 0.5 T. 相似文献
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大容量电气设备(如变压器、电缆等)在现场进行工频交流耐压试验因受试验条件限制而难以进行。上海久隆电气设备试验有限公司研制的选用变频谐振系统作为交流耐压装置,解决了大容量电气设备现场进行交流耐压试验的难题,分析了该装置的目标设定、方案选择,以及设计原理和参数设计。交流耐压装置在不同类型变压器和电力电缆的现场应用,证明其实用性。 相似文献
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换流变压器是特高压直流输电系统中的关键设备,其阀侧承受着交直流复合电压。研究热老化对交直流电压在油纸绝缘内分布的影响,可为换流变压器油纸选型提供理论借鉴。选取了换流变压器常用的绝缘油和绝缘纸作为研究对象,并对2种不同油纸组合展开加速热老化试验,测量并分析试验过程中绝缘油和绝缘纸的介电常数和电阻率的变化规律,在此基础上通过油-绝缘纸-油有限元电场仿真模型分析,基于线性叠加原则,得到了交直流电压在热老化过程中的分布变化情况,表明热老化主要影响油纸中直流分量的分布,将显著提高油中的电场强度。 相似文献
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《Dielectrics and Electrical Insulation, IEEE Transactions on》2007,14(1):125-129
Long rod insulators made of porcelain and disc type insulators made of porcelain or glass are the main types of HV insulators used since more than 60 years in overhead transmission and distribution lines and also will be the dominating products in the future. Historically based, there exists much published work on the electrical pollution performance of disc (cap and pin) type HV insulators. Only little knowledge exists about the good service pollution performance of the long rod type insulators. This paper compares the test results obtained from artificial pollution tests according to IEC 61245 with both types of HV insulators under same test conditions. The tests were performed with DC voltage at the FGH (Forschungsgemeinschaft fur Elektrische Anlagen), an independent German high voltage test laboratory. It is well known that the sensitivity of insulator strings to pollution effects is much higher at DC than at AC (50 Hz power frequency) voltage. The test results show an equivalent pollution performance of long rod and disc (cap and pin) type insulators under the same pollution conditions and the same electrical stresses 相似文献
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AC superconducting wire is being developed for such electrical equipment as superconducting transformers and superconducting generators. AC loss reduction is of primary concern in the development of such high-efficiency equipment. In reducing ac losses, it is necessary to develop assessment methods for ac loss in test samples which have shapes similar to the end-product equipment. This paper described a least squares calculation of ac losses of superconducting wire as a function of frequency and magnetic field strength measured in test coils. Two sample solenoid coils were made to test the influence of different capacities and winding methods on ac losses in ac superconducting coils with rated capacities of 500 kVA and 20 kVA, and impregnated (epoxy resin) and nonimpregnated windings. The ac losses in the superconducting coils were measured by a calorimetric method using the evaporating rates of liquid helium. Estimated ac losses in the superconducting wire of the two coils were compared with Joule losses of copper conductors at ambient temperature. As a result of this comparison, a low-loss ac superconducting wire winding can be made for electrical equipment rather than employing conventional copper winding when used under low magnetic fields less than 0.5 T. 相似文献