A Novel Strategy of Current Transformer Saturation Identification and Valid Data Application Based on Wavelet Packet
Xing Jiawei1, 2, Jin Neng1, Lin Xiangning1, Liu Yao1, Li Zhen3
1. State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China; 2. China-EU Institute for Clean and Renewable Energy Huazhong University of Science and Technology Wuhan 430074 China; 3. XJ Electric Corporation Limited Xuchang 461000 China
Abstract：In order to solve the busbar differential protection maloperation caused by the secondary side current distortion when saturation of current transformer occurs, a novel strategy of the current transformer saturation identification and valid data extraction is proposed in this paper. Current transformers connected to the same busbar within a substation were grouped based on the similarity of sampling information time-frequency characteristics in the first place. Then, an optimized wavelet packet algorithm was used to identify the mutation points of all the secondary currents in the same group. By comparing each mutation point of secondary current within the same group, whether current transformer saturation occurred could be determined, and the valid data segment after fault occurred was extracted for protection calculation. According to the length of different valid data, different protection algorithms were applied to determine the fault types. Simulation results based on PSCAD verify that the proposed method can locate all the mutation points of the secondary current and identify different kinds of current transformer saturation accurately. Furthermore, the proposed method can effectively deal with fast saturation, interference, and transferring fault.
邢家维, 金能, 林湘宁, 刘尧, 李贞. 基于小波包变换的电流互感器饱和识别及有效数据运用策略[J]. 电工技术学报, 2019, 34(6): 1170-1179.
Xing Jiawei, Jin Neng, Lin Xiangning, Liu Yao, Li Zhen. A Novel Strategy of Current Transformer Saturation Identification and Valid Data Application Based on Wavelet Packet. Transactions of China Electrotechnical Society, 2019, 34(6): 1170-1179.
[1] 陈学伟, 高厚磊, 向珉江, 等. 基于电子式互感器微分输出的改进R-L模型距离保护算法[J]. 电工技术学报, 2014, 29(6): 283-289. Chen Xuewei, Gao Houlei, Xiang Minjiang, et al.Improved R-L model distance protection algorithm based on differential output of electronic trans- ducers[J]. Transactions of China Electrotechnical Society, 2014, 29(6): 283-289. [2] 陈敦辉, 苏舒, 林湘宁, 等. 基于历史数据纵向协同性的电子式互感器伴随故障甄别策略[J]. 电工技术学报, 2017, 32(23): 115-126. Chen Dunhui, Su Shu, Lin Xiangning, et al.The identification strategy of transformer synchronous fault based on synergy of historical data[J]. Transa- ctions of China Electrotechnical Society, 2017, 32(23): 115-126. [3] 李岩, 陈德树, 张哲. 鉴别CT饱和的改进时差法研究[J]. 继电器, 2001, 29(11): 1-4, 8. Li Yan, Chen Deshu, Zhang Zhe.Improved time difference method on identifying CT saturation[J]. Relay, 2001, 29(11): 1-4, 8. [4] 林湘宁, 刘沛, 高艳. 基于数学形态学的电流互感器饱和识别判据[J]. 中国电机工程学报, 2005, 25(5): 44-48. Lin Xiangning, Liu Pei, Gao yan. A novel method to identify the saturation of the current transformer using mathematical morphology[J]. Proceedings of the CSEE, 2005, 25(5): 44-48. [5] 李贵存, 刘万顺, 贾清泉, 等. 利用小波原理检测TA饱和的新方法[J]. 电力系统自动化, 2001, 25(5): 36-39. Li Guicun, Liu Wanshun, Jia Qingquan, et al.A novel method to identify TA saturation using wavelet principle[J]. Automation of Electric Power System, 2001, 25(5): 36-39. [6] 公茂法, 夏文华, 张晓明, 等. 基于HHT的抗CT饱和变压器故障识别新方法. 电力系统保护与控制, 2013, 41(22): 64-70. Gong Maofa, Xia Wenhua, Zhang Xiaoming, et al.New method to identify transformer fault with anti-CT saturation based on HHT[J]. Power System Protection and Control, 2013, 41(22): 64-70. [7] 王志鸿, 郑玉平, 贺家李. 通过计算谐波比确定母线保护中TA的饱和[J]. 电力系统及其自动化学报, 2000, 12(5): 19-24. Wang Zhihong, Zheng Yuping, He Jiali.A algorithm to distinguish current transformer’s saturation calculating the harmonic ratio of branch current[J]. Proceedings of the EPSA, 2000, 12(5): 19-24. [8] 浦南桢, 翟学锋, 袁宇波, 等. P级TA饱和对数字式比率制动特性差动保护的影响[J]. 电力自动化设备, 2003, 23(4): 76-80. Pu Nanzhen, Zhai Xuefeng, Yuan Yubo, et al.Impaction of P-type CT saturation on digital ratio- restrained differential protection[J]. Electric Power Automation Equipment, 2003, 23(4): 76-80. [9] 刘晓阳, 赵洋, 曹云东, 等. 基于小波变换的交流系统串联电弧故障诊断[J]. 电工技术学报, 2014, 29(1): 10-17. Liu Xiaoyang, Zhao Yang, Cao Yundong, et al.Series arc fault diagnosis based on wavelet transform in AC system[J]. Transactions of China Electro- technical Society, 2014, 29(1): 10-17. [10] 卢其威, 王涛, 李宗睿, 等. 基于小波变换和奇异值分解的串联电弧故障检测方法[J]. 电工技术学报, 2017, 32(17): 208-217. Lu Qiwei, Wang Tao, Li Zongrui, et al.Detection method of series arcing fault based on wavelet transform and singular value decomposition[J]. Transactions of China Electrotechnical Society, 2017, 32(17): 208-217. [11] 曹豫宁, 李永丽, 张兴华, 等. 基于小波变换的电流互感器饱和实时检测新判据[J]. 电力系统自动化, 2001, 25(10): 27-30. Cao Yuning, Li Yongli, Zhang Xinghua, et al.A new on-line criterion for current transformer saturation based on wavelet transform[J]. Automation of Electric Power Systems, 2001, 25(10): 27-30. [12] 叶瑞丽, 郭志忠, 刘瑞叶, 等. 基于小波包分解和改进Elman神经网络的风电场风速和风电功率预测[J]. 电工技术学报, 2017, 32(21): 103-111. Ye Ruili, Guo Zhizhong, Liu Ruiye, et al.Wind speed and wind power forecasting method based on wavelet packet decomposition and improved Elman neural network[J]. Transaction of China Electrotechnical Society, 2017, 32(21): 103-111. [13] 袁莉芬, 孙业胜, 何怡刚, 等. 基于小波包优选的模拟电路故障特征提取方法[J]. 电工技术学报, 2018, 33(1): 158-165. Yuan Lifen, Sun Yesheng, He Yigang, et al.Fault feature extraction method for analog circuit based on preferred wavelet packet[J]. Transaction of China Electrotechnical Society, 2018, 33(1): 158-165. [14] 董泽, 谢华, 韩璞, 等. 小波变换模极大值消噪算法的研究[J]. 电力科学与工程, 2005(3): 12-16. Dong Ze, Xie Hua, Han Pu, et al.Denoising algo- rithm based on wavelet transform modulus maximum[J]. Electrical Power Science and Engineering, 2005(3): 12-16. [15] 尚海昆, 苑津莎, 王瑜, 等. 基于交叉小波变换和相关系数矩阵的局部放电特征提取[J]. 电工技术学报, 2014, 29(4): 274-281. Shang Haikun, Yuan Jinsha, Wang Yu, et al.Feature extraction for partial discharge based on cross- wavelet transform and correlation coefficient matrix[J]. Transaction of China Electrotechnical Society, 2014, 29(4): 274-281. [16] 邓祥力, 张哲, 尹项根. 基于小矢量技术的快速差动电流速断保护[J]. 电力系统自动化, 2012, 36(14): 67-71. Deng Xiangli, Zhang Zhe, Yin Xianggen.Fast differential current instantaneous trip protection based on phaselet algorithm[J]. Automation of Electric Power Systems, 2012, 36(14): 67-71.
2019, Vol. 34 
