励磁涌流对变压器差动保护影响的分析与探讨

通过对变压器励磁涌流波形特点的分析,探讨了其差动保护可靠性及其与高压试验之间的关系。以一起大型变压器（电压等级为500kV）的差动保护误动的实际案例进行分析,对其现场第一手数据和试验波形进行研究和分析,发现为避免励磁涌流引发了变压器差动保护的误动作,现场技术人员在进行差动保护整定计算的过程中,不仅要使所用参数、数据符合相关的规程和标准,熟悉差动保护的特性,同时也必须要了解高压试验对变压器励磁涌流特性的影响,并且还要更充分地发挥现代微机录波装置等仪器的作用,才能尽可能地提高变压器差动保护的实际效果。

Analysis and Discussion of the Effect of the Exciation Surge on the Transformer Differential Protection

By the analysis of the characteristic of the tranformer′s excitation surge waveforms,the relations between reliability of the differential protection and its high voltage test are discussed.Taking a practical case of the differential protection malfunction of a large transformer（Voltage rating of 500kV） to analyze.The firsthand data and the test waveform for the site are studied and analyzed to find that to avoid the excitation surge to cause the transformer differential protection malfunction,when the technicians on the site carry out the setting calculation of the differential protection,they make not only the parameters and data to be used with meet the specification of the related rules and standards but also know the effect of the high voltage test on the excitation surge characteristics of the transformer.Meantime,we must fully give play to modern microcomputer oscillograph to increase practical effect of the transformer differential protection.