基于Yn/Δ接线变压器零序纵差保护原理研究  

Study of zero-sequence differential protection for transformer withYn/Δ connection

作　　者：索南加乐[1] 张军民[1] 许立强[1] 谈树峰[1] 焦在滨[1] 杜斌[1] 赵选宗[1] 

机构地区：[1]西安交通大学电气工程学院,陕西西安710049

出　　处：《电力系统保护与控制》2010年第16期54-61,共8页Power System Protection and Control

基　　金：国家自然科学基金项目(NO.50677051);国家自然科学基金项目(NO.50877061);国家重点基础研究发展计划(973计划;NO.2009CB219704)

摘　　要：变压器传统电流差动保护在反映接地故障及匝间故障时灵敏度存在着不足,由此提出了在变压器区内弱故障时仍能可靠动作的基于零序电流的纵差保护方案,不同于目前所说的零序电流差动只是针对变压器Y侧绕组应用,利用Y以及?侧绕组中的零序电流构成差动保护。按照典型的电流互感器配置方案,?侧绕组电流未知,采用零序等值电路计算?侧绕组中的零序环流,PSCAD仿真以及动模数据均验证了该方法的正确性。通过变压器各种故障情况下零序纵差保护和传统保护性能的比较表明:零序电流纵差保护在反映单相接地和小匝间短路时灵敏度更高,且受励磁涌流影响更小。Because conventional differential protection is not sensitive enough to earthing fault and inter-turn fault,a differential protection method based on zero-sequence current is proposed which can still reliably operate when transformer internal weak fault occurs.Different from present scheme,the new protection scheme is constructed by using the zero-sequence current of each side.The zero-sequence loop current in the delta side can be calculated by the zero-sequence equivalent circuit according to typical CT configuration scheme and unknown current in delta side.Simulation with PSCAD and dynamic model data show that the proposed principle is correct.The comparisons between the performance of zero-sequence differential protection and conventional differential protection suggest that the zero-sequence differential protection has higher sensitivity to earthing fault and small inter-turn fault,and suffers less influence from inrush.

关 键 词：变压器 零序等值电路 Y-Delta绕组 零序电流纵差保护 

分 类 号：TM772[电气工程—电力系统及自动化]