摘要
随着远距离风电外送系统并网引起的次同步振荡现象和风险的增加,电力变压器经常会运行在含次同步分量的条件下,其铁心的非对称偏置磁化会导致谐波畸变和无功功率增加。含次同步分量下电力变压器铁心无功功率分析属于时-频域混合计算问题。针对该问题,首先,在时域下建立基于定点法的三维场路耦合有限元模型并编写计算程序,以求取不同次同步分量注入时变压器的励磁电流;其次,提出通过最大基波无功和平均基波无功的变压器基波无功特性分析方法,以及基于多重矢量功率理论的变压器频域无功特性分析方法;再次,通过一台物理变压器模型的空载实验,验证该文提出的时域场路耦合模型能够准确模拟变压器励磁电流中显著分量的频谱特性;最后,通过对该模型的仿真,分别对变压器的基波无功特性和多频率无功特性进行计算,并对计算结果进行分析讨论。
With the increase of subsynchronous oscillation phenomena and risks caused by long-distance wind power transmission systems,power transformers often operate with subsynchronous components,which causes asymmetrical bias magnetization of the core and leads to harmonic distortion and increase in reactive power.Aiming at this mixed time-frequency domain problem of power transformer reactive power with subsynchronous components,firstly,this paper established a 3D field-circuit coupling finite element model based on the fixed-point method to solve the magnetizing current.Secondly,the analysis method of transformer fundamental reactive power characteristics based on the maximum fundamental reactive power and average fundamental reactive power,and a transformer multi-frequency reactive characteristics analysis method based on the multivector power theory are proposed.Thirdly,the no-load experiment of a physical transformer model shows that the time-domain field-circuit coupling model proposed in this paper can accurately simulate the spectral characteristics of the significant components in the magnetizing current.Finally,through the simulation of this transformer,the fundamental reactive power characteristics and multi-frequency reactive power characteristics of the transformer are calculated and analyzed.
作者
孙佳安
李琳
于静茹
Sun Jia’an;Li Lin;Yu Jingru(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University,Beijing 102206 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2022年第20期5104-5116,共13页
Transactions of China Electrotechnical Society
基金
国家重点研发计划课题(2021YFB2401703)
国家自然科学基金(52177005)资助项目。
关键词
次同步频率分量
变压器偏置磁化
三维场路耦合有限元
无功功率
多重矢量功率理论
Subsynchronous frequency components
asymmetric bias
3D field-circuit coupling finite element
reactive power
multivector power theory
