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介绍了江苏镇江供电公司220kV变电所主变压器与电容器的运行情况.通过某220kV变电所运行的实例和潮流理论计算分析,研究电容器在主变压器的低压侧轻载时甚至空载时可行性,并指出该电容器投切运行条件。 相似文献
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葛洲坝换流站调试领导小组 《华中电力》1989,(2):33-33
5月4日葛洲坝换流站站系统调试进行了投切空载换流变压器试验。试验的目的在于考核换流变压器空载投切过程中承受励磁涌流的冲击能力、过电压水平及继电保护装置在投切过程中的行为,试验达到了预期的目的。 相似文献
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1概述为考核草铺变电站投产前500kV变压器耐受冲击合闸的能力,考核SF6开关切合空载变压器的性能以及测试切合时产生的过电压水平,1993年6月22日对该站1号主变压器进行了切合空载变压器试验。由于当时500kV系统电源不具备作试验的条件,试验在220kV侧进行。从220kV侧进行切合空载变压器试验,使用GFAI-N型SF6开关,利用220kV系统电源,分别对1号主变压器作了切合试验各5次,录取了500kV220kV35kV三侧电压波形,220kV侧电流波形,500kV、220kV两侧氧化锌避雷器动作电流波形,总共6组18个信号。试验时变压器处在正常工况下,在500k… 相似文献
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针对500kV南阳白河变电站和新乡获嘉变电站系统调试中进行的500kV空载线路投切试验,对三条500kV空载线路投切过程中测录到的分闸过电压及合闸过电压等暂态数据作了分析。 相似文献
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随机合闸空载变压器产生的励磁涌流容易引起电力变压器差动保护装置误动、绕组机械应力增大以及电能质量降低等问题。采用选相合闸技术来抑制空载变压器励磁涌流。实现空载变压器选相合闸的关键是有效预估变压器切除后铁芯中的剩磁。在分析选相合闸空载变压器原理的基础上,提出基于数值积分的铁芯剩磁测量方法。采用PSCAD/EMTDC软件对变压器空载合闸进行了仿真,仿真结果验证了选相合闸技术的有效性。搭建空载变压器选相投切试验平台,进行了空载变压器随机合闸、选相合闸试验。试验结果表明:与随机合闸相比,计及剩磁的空载变压器选相合闸能够有效地抑制励磁涌流,同时验证了剩磁测量方法的有效性。最后,针对三相联动断路器提出了相适应的空载变压器选相合闸策略,仿真结果验证了其有效性。 相似文献
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高压断路器在随机关合空载变压器时会产生幅值、频率很高的涌流和过电压,从而可能导致继保装置误动、变压器绕组机械应力增加和用户电能质量下降。采用同步开关技术选相关合空载变压器能有效减少励磁涌流和操作过电压。分析了空载变压器同步关合的原理和最佳目标关合相位确定,提出空载变压器铁芯剩磁计算方法,并采用最小二乘算法实现剩磁计算。最后,采用ATP-EMTP建立空载变压器同步关合仿真模型,验证了提出的空载变压器同步关合和铁芯剩磁计算算法有效性,为空载变压器的同步关合减少励磁涌流和过电压提供了理论基础。 相似文献
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在线监测获取的电力系统过电压波形分析 总被引:1,自引:1,他引:0
电力系统中出现的波形、幅值及持续时间各异的多种过电压对电气设备绝缘构成了严重威胁。鉴于电力系统过电压波形包含了丰富的电力系统工作状况和状态信息,笔者重点对电力系统过电压波形进行了分析,将从变电站过电压在线监测系统获取的雷电感应过电压、投电容器组过电压、合空载线路过电压、投切空载变压器过电压、弧光接地过电压、不对称接地短路共7种典型过电压波形作为对象,分析其主要特征,并通过小波变换,使含有高频分量的过电压特征在时频域得到更好的体现,为过电压特征提取及类型识别奠定基础。 相似文献
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Ananian Lucas G. Miller Keith W. Titus Charles H. Walsh George W. 《Industry Applications, IEEE Transactions on》1983,(6):914-919
Reported here are the results of a field investigation of switching-produced transients associated with vacuum circuit breaker switching of an unloaded low-voltage substation transformer. A sufficient sampling of data has been obtained and documented to provide a good statistical basis for this important mode of switching in a very prevalent application area. The results of this field measurements program confirm that the transient voltage environment created by such switching is within, by a wide margin, the expected transient capabilities of the associated power distribution equipment?specific evaluation being made with respect to the switched transformer. 相似文献
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针对随机关合空载变压器产生励磁涌流的问题,采用选相关合技术来抑制励磁涌流。在分析选相关合空载变压器原理的基础上,研究了同时合闸策略、快速合闸策略和延时合闸策略下铁芯磁通的变化规律,并对比分析三种合闸策略的适用条件。最后搭建选相投切10 kV空载变压器实验平台,对有无剩磁时不同关合相位下的励磁涌流进行分析。实验结果表明:变压器铁芯无剩磁时,在电压峰值处合闸可以有效抑制励磁涌流;铁芯存在剩磁时,在电压峰值处合闸仍会产生励磁涌流。因此,有必要预测铁芯剩磁以确定最佳合闸相位,实现空投变压器的无冲击平滑过渡。 相似文献
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Abbas Ketabi Iman Sadeghkhani Rene Feuillet 《Electrical Engineering (Archiv fur Elektrotechnik)》2013,95(3):241-253
In this work, voltage evaluation after power components energization such as transmission line, transformer and shunt reactor is analyzed using artificial neural network (ANN)-based approach. Throughout the initial phase of system restoration, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. Such an overvoltage might damage some equipment and delay power system restoration. In the cases of transformer and shunt reactor energization, ANN is trained with the worst case scenario of switching angle and remanent flux which reduce the number of required simulations for training ANN. Moreover, for achieving good generalization capability for developed ANN, equivalent parameters of the network are used as ANN inputs. The simulated results for a partial of 39-bus New England test system show that the proposed technique can estimate the peak values and duration of overvoltages during network switching with good accuracy. 相似文献
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From failure experience on power transformers, it was very often suspected that inrush currents, occurring when energizing unloaded transformers, were reason for damage. In this paper, it was investigated how mechanical forces within the transformer coils build up under inrush compared to those occurring at short circuit. Two-dimensional and three-dimensional computer modeling for a real 268 MVA, 525/17.75 kV three-legged step up transformer was employed. The results show that inrush current peaks of 70% of the rated short circuit current cause local forces in the same order of magnitude as those at short circuit. The resulting force summed up over the high voltage coil is even three times higher. Although inrush currents normally are smaller, the forces can have similar amplitudes as those at short circuit however with longer exposure time. Therefore, care has to be taken to avoid such high inrush currents. Today controlled switching offers an elegant and practical solution 相似文献