特高压直流换流变压器励磁涌流引起保护动作分析

Analysis of UHVDC Converter Transformer Protective Action Caused by Magnetizing Inrush Current

换流变压器及引线差动保护中有励磁涌流识别逻辑,换流变压器充电成功与否与换流变压器励磁涌流密切相关。文中通过介绍换流变压器及引线差动保护配置,结合一起典型的换流变充电时励磁涌流引起保护动作的事件,分析指出传统换流变压器及引线差动保护逻辑的不足,提出了将换流变单相星星变、星角变二次谐波判据引入励磁涌流识别,经过实际充电证实改进后的逻辑正确。

The converter connection-transformer differential protection includes inrush current recognition logic, the success of the converter transformer is closely related to magnetizing inrush current of the converter transformer. Through introducing configuration of the converter connection-transformer differential protection and combining a typical event of the transformer protective action caused by magnetizing inrush current, this paper analyses the problem of converter connectiontransformer differential protection logic and proposes to introduce single phase star transformer and star-angle transformer second harmonic into distinguish of inrush current. By experimenting, it proves the improved logic correct.