摘要
当配电变压器中发生局部放电时,脉冲电流信号会沿着绕组传播,检测低压绕组中性点接地处脉冲电流即可实现配电变压器局部放电检测。以往的配电变压器局部放电检测及评价方法无法判断放电位置与放电类型,难以准确评估配电变压器绝缘状态。建立了配电变压器宽频等值电路模型,研究了不同位置、不同类型局部放电脉冲电流信号在配电变压器绕组中的传播规律,提出了小波-经验模态联合去噪算法过滤现场检测中的噪声信号。通过计算脉冲电流信号的能量值以及三相波形相似系数实现了配电变压器局部放电的电气定位,以对多组不同噪声水平的信号进行验证,均可实现准确定位,验证了去噪算法和定位方法的有效性。
When partial discharge occurs in the distribution transformer,the pulse current signal will propagate along the winding,and the partial discharge detection of the distribution transformer can be realized by detecting the pulse current at the grounding of the neutral point of the low-voltage winding.The previous partial discharge detection methods for distribution transformers cannot determine the location and type of partial discharge,and it is difficult to accurately assess the insulation status of distribution transformers.In this paper,a broadband equivalent circuit model of distribution transformer is established,and the propagation law of partial discharge pulse current signals of different locations and types in distribution transformer windings is studied.A wavelet-empirical mode joint denoising algorithm is proposed to filter the noise signal in field detection.By calculating the energy value of the pulse current signal and the similarity coefficient of the three-phase waveform,the electrical localization of the partial discharge of the distribution trans-former is realized to verify the multiple groups of signals with different noise levels,and accurate positioning can be achieved.Effectiveness of algorithms and localization methods.
作者
王帅
刘广军
张博文
丁宁
穆海宝
WANG Shuai;LIU Guangjun;ZHANG Bowen;DING Ning;MU Haibao(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,Shaanxi,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,Shaanxi,China)
出处
《电网与清洁能源》
CSCD
北大核心
2023年第3期40-47,共8页
Power System and Clean Energy
基金
陕西省重点研发计划项目(2021GXLH-Z-061)
中铁第一勘察设计院集团有限公司科技项目(2021KY12ZD(ZNGT)-01-01)。
关键词
配电变压器
局部放电定位
脉冲电流法
小波分解去噪
distribution transformer
partial discharge localization
pulsecurrentmethod
waveletdecompositiondenoising
