变压器过励磁保护的测量点分析  

Analysis of measuring point for transformer over-excitation protection

作　　者：姚旭[1] 何世恩[2] 沈利平[3] 

机构地区：[1]甘肃电力调度通信中心,甘肃兰州730050 [2]甘肃省电力公司风电技术中心,甘肃兰州730050 [3]甘肃省电力公司刘家峡水电厂,甘肃永靖731600

出　　处：《电力自动化设备》2010年第9期138-142,共5页Electric Power Automation Equipment

摘　　要：变压器过励磁保护判据推导过程中变压器绕组实际匝数(W)等于额定匝数(WN)这一重要假设,是变压器过励磁保护测量点选择时应注意的。变电站主变压器过励磁保护测量点不应选择在主变调压侧,发电厂升压变压器应选择在低压侧;否则就不能正确反映变压器的过励磁状况,有可能引起过励磁保护拒动或误动。同时变压器过励磁保护测量点的选取,应考虑正常检修和故障时,尽量不影响其对变压器励磁状况的判断。对一个330 kV变电站在其联络线路故障和恢复送电过程中、在其330 kV侧电压互感器(TV)转检修操作过程中主变过励磁保护的动作行为,及一个发电厂的发变组在启动过程中由于操作失误引起主变过励磁时的保护动作行为进行分析,提出了主变过励磁保护测量点的改进方案。During the selection of measuring point for transformer over-excitation protection,the assumption of the actual turn number of transformer windings（W） being equal to the rated turn number（WN） for the derivation of its criterion should be noticed.For the main transformer of substation,it should not be at its voltage regulation side and for the step-up transformer of power plant,it should be at its low voltage side,otherwise the transformer over-excitation can not be correctly reflected,resulting in the improper protection operations.Meanwhile,the selection of measuring point should not affect the judgment of transformer excitation conditions during normal maintenance and fault detection.The behavior of the main transformer over-excitation protection of a 330 kV substation during the tie-line fault and power supply restoration and during the maintenance of PT at 330 kV side is analyzed.The behavior of the main transformer over-excitation protection of a power plant generator-transformer set during startup is also analyzed.Improved schemes of main transformer over-excitation protection for power plant and substation are proposed.

关 键 词：变压器 过励磁保护 测量点 变电站 有载调压 无载调压 

分 类 号：TM403.5[电气工程—电器]