10kV站用变压器差动保护动作分析与处理  

Analysis and Treatment on Differential Protection of 10kV Station Transformer

作　　者：杨帆[1] 宋天奇[1] 张雪波[1] 曹军[1] 

机构地区：[1]中国南方电网超高压输电公司,广东广州510620

出　　处：《广东电力》2014年第5期72-74,89,共4页Guangdong Electric Power

摘　　要：针对±800 kV侨乡换流站10 kV站用变压器投入过程中差动保护误动作的情况,结合现场录波图,通过计算和分析,得出导致变压器保护误动作的主要原因是保护整定中所选择的变压器联结组别与实际不符、保护装置采样精度不足。采取了以过流保护替代差动保护作为主保护、根据变压器实际联结方式重新进行保护整定等措施后,站用变压器成功投运。依据标准和规范提出建议:电压在10 kV及以下、容量在10 MVA及以下的变压器可采用电流速断保护;如需配置差动保护,应综合考虑最大短路电流和电流互感器变比。Aiming at differential protection malfunction in input process of 10 kV station transformer of ±800 kV Qiaoxiang convertor station, by combining field wave record figure and calculation and analysis, this paper considers main reasons for causing differential protection malfunction of the transformer are discrepant joint groups of the selected transformers for protection setting with reality and deficient sampling precision of the protection device. After adopting measures of replacing differential protection by over current protection and carrying out protection setting again according to practical joint way of the transformer, it is able to successfully put station transformer into operation. According to standards and specifications, it suggests to use current quick-break protection for transformers of 10 kV or under 10 kV voltage and 10 MVA or under 10 MVA capacity. In addition, if it is necessary to configure differential protection, it suggests to consider maximum short cir- cuit current and ratio of transformation of current transformer.

关 键 词：站用变压器 差动保护 二次谐波制动 

分 类 号：TM774.1[电气工程—电力系统及自动化]