变压器饱和特性对无功盈余下系统过电压影响的仿真研究  

Simulation Study on the Influence of Transformer Saturation Characteristics on Overvoltage Under Reactive Power Surplus

作　　者：张培夫 葛景 王新宝[1] 常宝立[1] 俞秋阳[1] ZHANG Peifu;GE Jing;WANG Xinbao;CHANG Baoli;YU Qiuyang(NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211102

出　　处：《山东电力技术》2024年第11期85-92,共8页Shandong Electric Power

基　　金：国家重点研发计划项目(2021YFB2400805)。

摘　　要：直流换相失败、直流闭锁等故障期间,换流站无功功率盈余会导致送端交流系统出现较高的过电压,并向近区新能源机端传递,严重时可能会造成新能源脱网,危害电力系统安全运行。现有的过电压分析研究中对变压器饱和对过电压的影响考虑较少,为此,本文从过电压导致变压器铁芯饱和的机理出发,研究了变压器铁芯饱和特性对过电压的影响。理论分析表明,考虑变压器饱和后,无功盈余所造成的过电压现象有所缓解。随后基于DIgSILENT和PSCAD仿真软件搭建了过电压仿真模型进行分析对比和验证。结果表明仿真分析与理论分析相一致,变压器饱和后可一定程度上降低系统过电压。研究表明,过电压越高、铁芯饱和越严重、变压器空心电抗越大,变压器级数越多对过电压的影响程度越大。During DC commutation failure,DC blocking and other faults,the surplus reactive power may lead to a high overvoltage in the AC system at the sending terminal,and will be transmitted to the new energy terminal in the near zone,which may cause new energy units off-grid in severe cases,endangering the safe operation of the power system.The existing overvoltage studies has rarely considered the influence of transformer saturation on overvoltage.Therefore,this paper began by introducing the mechanism of transformer saturation caused by overvoltage,and then investigated the influence of transformer core saturation characteristics on overvoltage.Theoretical analysis indicated that the overvoltage caused by the surplus reactive power was alleviated when we factored in the effects of transformer saturation.Secondly,the overvoltage simulation model was built by DIgSILENT and PSCAD simulation software for analysis,comparison and verification.Furthermore,the results show that the simulation analysis is consistent with the theoretical analysis,and the system overvoltage can be reduced to some extent when transformer is saturated.In addition,the simulated results indicate that the higher the overvoltage,the more serious core saturation,the larger the air reactance of transformer and the more transformer series,the more significant effect on the overvoltage become.

关 键 词：变压器饱和特性 过电压 无功盈余 电力系统仿真 

分 类 号：TM743[电气工程—电力系统及自动化]