Analysis of the Helping Effect and Engineering Calculation Method for Transformer Circulating Current in Delta Winding
Cao Wenbin1,2, Yin Xianggen1,2, Zhang Zhe1,2, Wang Yuxue3, Pan Yuanlin1,2
1. State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China; 2. Hubei Province Key Laboratory Electric Power Security and High Efficiency Huazhong University of Science and Technology Wuhan 430074 China; 3. Power Dispatching Control Center of Guangdong Power Grid Guangzhou 510000 China
Abstract:The helping effect of circulating current in the delta winding of Y-D-connected transformer will cause the primary inrush current to be distorted, and the reliability of the inrush current restraint criterion based on the typical characteristics of magnetizing inrush current will be affected. The generating mechanism, the helping effect and the influencing factors of the circulating current were revealed through the differential equation and mechanism analysis. It shows that the primary current of unsaturated phase is equal to the circulating current. Based on this, it was proposed to use the intermediate value of the three-phase primary inrush current as quasi circulating current instead of the actual circulating current to compensate the primary inrush current, so that the primary inrush current will have typical characteristics of magnetizing inrush current and will be more easily identified. The adaptability analysis of the method in the presence of remanence shows that it has good engineering practicability. The method has nothing to do with the grounding mode, and does not require the system voltage to be balance or symmetrical. Simulations and recorded waveforms have verified the effectiveness of the method.
曹文斌, 尹项根, 张哲, 王育学, 潘远林. 变压器三角绕组环流助增作用分析及其工程求取方法[J]. 电工技术学报, 2020, 35(15): 3161-3172.
Cao Wenbin, Yin Xianggen, Zhang Zhe, Wang Yuxue, Pan Yuanlin. Analysis of the Helping Effect and Engineering Calculation Method for Transformer Circulating Current in Delta Winding. Transactions of China Electrotechnical Society, 2020, 35(15): 3161-3172.
[1] 郑涛, 陆格野, 赵彦杰, 等. 基于虚拟等效电感的特高压调压变压器励磁涌流判别算法[J]. 电工技术学报, 2016, 31(7): 118-125. Zheng Tao, Lu Geye, Zhao Yanjie, et al.A discriminating algorithm for identifying inrush of UHV voltage-regulating transformer based on virtual equivalent inductance[J]. Transactions of China Electrotechnical Society, 2016, 31(7): 118-125. [2] 潘超, 金明权, 蔡国伟, 等. 基于变压器励磁电流辨识的直流失稳与抑制策略[J]. 电工技术学报, 2018, 33(18): 4267-4276. Pan Chao, Jin Mingquan, Cai Guowei, et al.DC instability and suppression strategy of transformer based on exciting-current identification[J]. Transactions of China Electrotechnical Society, 2018, 33(18): 4267-4276. [3] 王业, 袁宇波, 高磊, 等. 基于FSAD及非周期分量的励磁涌流鉴别算法[J]. 电工技术学报, 2015, 30(21): 127-135. Wang Ye, Yuan Yubo, Gao Lei, et al.A algorithm to identify magnetizing inrush current based on FSAD and aperiodic components[J]. Transactions of China Electrotechnical Society, 2015, 30(21): 127-135. [4] Wu Wencong, Ji Tianyao, Li Mengshi, et al.Using mathematical morphology to discriminate between internal fault and inrush current of transformers[J]. IET Generation, Transmission & Distribution, 2016, 10(1): 73-80. [5] 周念成, 李春艳, 王强钢. 基于多变量多尺度熵的变压器励磁涌流识别方法[J]. 电工技术学报, 2018, 33(15): 3426-3436. Zhou Niancheng, Li Chunyan, Wang Qianggang.An algorithm to identify transformer inrush currents based on multivariate multiscale sample entropy[J]. Transactions of China Electrotechnical Society, 2018, 33(15): 3426-3436. [6] 袁宇波, 陆于平, 李澄, 等. 三相涌流波形特征分析及差动保护中采用二次谐波相位制动的原理[J]. 中国电机工程学报, 2006, 26(19): 23-28. Yuan Yubo, Lu Yuping, Li Cheng, et al.The characteristic analysis of three phase transformer inrush and the discussion of second harmonic restrained method using phase angle and amplitude[J]. Proceedings of the CSEE, 2006, 26(19): 23-28. [7] 袁宇波, 陆于平, 陈久林, 等. 变压器三角形侧零序环流助增对差动保护的影响[J]. 电力系统自动化, 2006, 30(3): 44-50. Yuan Yubo, Lu Yuping, Chen Jiulin, et al.Influence of add-assist circulation current at delta side on Y/delta transformer different protection[J]. Automation of Electric Power Systems, 2006, 30(3): 44-50. [8] 尹项根, 曹文斌, 潘远林, 等. 高阻抗电力变压器涌流特性及其对保护影响的研究[J]. 电力系统保护与控制, 2018, 46(20): 1-11. Yin Xianggen, Cao Wenbin, Pan Yuanlin, et al.Inrush current characteristic of high-impedance transformers and its impact on protective relays[J]. Power System Protection and Control, 2018, 46(20): 1-11. [9] 凌光, 姚文熙. Y/Δ接线变压器三角形侧环流计算新方法[J]. 电力自动化设备, 2015, 35(10): 157-162. Ling Guang, Yao Wenxi.Circulating current calculation for delta windings of transformer with Y/Δ connection[J]. Electric Power Automation Equipment, 2015, 35(10): 157-162. [10] 王雪, 王增平. 新型变压器三角形侧绕组环流计算方法[J]. 电力系统自动化, 2011, 35(24): 59-62. Wang Xue, Wang Zengping.A new method of calculating current in delta windings of transformers[J]. Automation of Electric Power Systems, 2011, 35(24): 59-62. [11] 夏石伟, 郑涛. Y,d接线变压器三角形侧绕组中环流求取方法[J]. 电力系统自动化, 2008, 32(24): 60-64. Xia Shiwei, Zheng Tao.Calculation of circulating current in delta winding of transformers with Y,d connection[J]. Automation of Electric Power Systems, 2008, 32(24): 60-64. [12] 潘超, 衣双园, 蔡国伟, 等. 交直流混杂模式下变压器励磁-振动特性研究[J]. 电工技术学报, 2019, 34(18): 3788-3796. Pan Chao, Yi Shuangyuan, Cai Guowei, et al.Excitation-vibration characteristics of transformer in AC-DC hybrid operation[J]. Transactions of China Electrotechnical Society, 2019, 34(18): 3788-3796. [13] 潘超, 王格万, 蔡国伟, 等. 交直流混杂模式下变压器励磁电流谐波与箱体损耗映射研究[J]. 电工技术学报,2019, 34(13): 2830-2838. Pan Chao, Wang Gewan, Cai Guowei, et al.Research on maping from excitation current harmonic to tank loss for AC-DC hybrid operation of transformer[J]. Transactions of China Electrotechnical Society, 2019, 34(13): 2830-2838. [14] 张学广, 张雅阁, 方冉, 等. 弱电网下双馈风电机组电网电压扰动补偿控制策略[J]. 电力系统自动化, 2020, 44(6): 146-159. Zhang Xueguang, Zhang Yage, Fang Ran, et al.Control strategy of disturbance compensation for grid voltage of DFIG based wind turbine in weak grid[J]. Automation of Electric Power Systems, 2020, 44(6): 146-159. [15] 徐少博, 陈嘉敏, 徐永海, 等. 级联型电力电子变压器三相电压暂降隔离能力分析[J]. 电力系统自动化, 2020, 44(4): 168-183. Xu Shaobo, Chen Jiamin, Xu Yonghai, et al.Analysis of three-phase voltage sag isolation capability of cascaded power electronic transformer[J]. Automation of Electric Power Systems, 2020, 44(4): 168-183. [16] 郑涛, 刘强, 夏石伟. 基于变压器回路方程的三角形侧绕组中环流求取新方法[J]. 电力系统自动化, 2009, 33(15): 43-46, 111. Zheng Tao, Liu Qiang, Xia Shiwei.New calculation method of the circulating current in delta side based on voltage loop equation of transformer[J]. Automation of Electric Power Systems, 2009, 33(15): 43-46, 111. [17] 毕大强, 梁武星, 柴建云, 等. 变压器三角形绕组中环流的构造方法[J]. 电力系统自动化, 2008, 32(1): 39-43. Bi Daqiang, Liang Wuxing, Cai Jianyun, et al.Research on constructing algorithm of circulating current in delta winding of transformers[J]. Automation of Electric Power Systems, 2008, 32(1): 39-43. [18] 李发海, 朱东起. 电机学[M]. 北京:科学出版社,2013. [19] 王维俭. 发电机变压器继电保护应用[M].北京:中国电力出版社,1998. [20] Sonnemann W K, Wagner C L, Rockefeller G D.Magnetizing inrush phenomena in transformer banks[J]. Transactions of the American Institute of Electrical Engineers. Part III: Power Apparatus and Systems, 1958, 77(3): 884-892. [21] Hamilton R.Analysis of transformer inrush current and comparison of harmonic restraint methods in transformer protection[J]. IEEE Transactions on Industry Applications, 2013, 49(4): 1890-1899. [22] 王瑞田, 肖飞, 范学鑫, 等. 三电平移相全桥直流变换器的变压器直流偏置分析与抑制[J]. 电工技术学报, 2019, 34(16): 3345-3354. Wang Ruitian, Xiao Fei, Fan Xuexin, et al.Analysis and suppression of transformer DC-bias for DC-DC converter with three-level phase-shift full-bridge topology[J]. Transactions of China Electrotechnical Society, 2019, 34(16): 3345-3354. [23] 焦在滨, 行武, 王钊, 等. 变压器励磁涌流负序二次谐波特征及机理[J]. 电力系统自动化, 2015, 39(11): 146-151. Jiao Zaibin, Xing Wu, Wang Zhao, et al.Features and mechanism of negative-sequence second harmonics of magnetizing inrush current in transformers[J]. Automation of Electric Power Systems, 2015, 39(11): 146-151. [24] Santagostino E C A G. Results of the inquiries on actual network conditions when switching magnetizing and small inductive and on transformer and shunt reactor saturation characteristics[J]. Electra, 1984(94): 35-53. [25] Brunke J H, Frohlich K J.Elimination of transformer inrush currents by controlled switching-part i: theoretical considerations[J]. IEEE Transactions on Power Delivery, 2001, 16(2): 276. [26] 王育学, 曹文斌, 黄明辉, 等. 变压器零模涌流解析分析及其等值电路[J]. 电网技术, 2018, 42(12): 3960-3968. Wang Yuxue, Cao Wenbin, Huang Minghui, et al.Mathematical analysis for zero-mode inrush current of transformer and its equivalent circuit[J]. Power System Technology, 2018, 42(12): 3960-3968. [27] 尹项根, 曹文斌, 潘远林, 等. 高阻抗变压器零模涌流特性与动模试验研究[J]. 电力系统保护与控制, 2020, 48(5): 1-9. Yin Xianggen, Cao Wenbin, Pan Yuanlin, et al.Study on zero-mode inrush current characteristics and dynamic physical simulation tests of high-impedance transformer[J]. Power System Protection and Control, 2020, 48(5): 1-9.