直流偏磁条件下变压器的谐波畸变特征  

Harmonic distortion feature of AC transformers caused by DC bias

作　　者：李贞[1] 李庆民[1] 李长云[1] 姚金霞[2] 刘民[2] 

机构地区：[1]山东大学电气工程学院,山东济南250061 [2]山东电力研究院,山东济南250002

出　　处：《电力系统保护与控制》2010年第24期52-55,共4页Power System Protection and Control

基　　金：教育部新世纪优秀人才支持计划项目(NCET-08-0335);国家电网公司科技项目

摘　　要：结合我国在建的±660kV直流输电线路(银川至青岛),基于建立的非线性磁模型,对距青岛换流站30km的220kV匡正站一号主变进行了谐波定量分析。结果表明,直流偏磁条件下变压器输出电压的偶次与奇次谐波含量均显著增加,使得变压器成为系统的严重谐波源。通过分析直流偏磁对变压器影响的相关因素,给出了该变压器输出电压偶次谐波含量与中性点注入直流的对应关系,为发展基于中性点反向注入电流的直流偏磁抑制方法提供了新思路。Combined with the undergoing ± 660 kV HVDC transmission line from Yinchuan to Qingdao,quantitative harmonic analysis of the No.1 main transformer of Kuangzheng substation which is 30 km away from the Qingdao converter station is carried out based on an established nonlinear magnetic model by PSCAD/EMTDC.The results indicate that, both the odd and even harmonic components are increasing significantly under DC bias than that without DC bias, which thereby makes the power transformers become the severe harmonic sources. Related factors of DC bias impact on the power transformers are discussed, and the relationship between the injected neural DC currents and the even harmonic ratio is established, which presents further potential for developing inverse-current-injection based DC bias suppression scheme.

关 键 词：变压器 直流偏磁 PSCAD/EMTDC 总谐波畸变率 谐波含有率 

分 类 号：TM401[电气工程—电器]