Distribution Network Voltage-Sag-Source Detection Method Based on Modified Incremental Impedance
Zhu Ke1,Wang Yixuan1,Liu Wenhua2
1. Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan 250061 China; 2. Dongying Power Supply Corporation Dongying 257091 China
Abstract：For the voltage sag source locating method based on real-part of the incremental impedance, the positive sequence component changes, which is caused by some asymmetry voltage sag, are sometimes too small to accurately locate. In order to solve this problem, a modified incremental impedance method for voltage-sag-source detection is proposed according to different types of voltage sag sources. The paper starts with the voltage-sag-source detection theory based on the incremental impedance, and derives the locating criteria for different types of voltage sag sources according to neutral point operation modes of domestic distribution networks. The voltage-sag-source detection strategy for Chinese radial distribution network is then accomplished after the analysis of voltage sag ride-through capability of the distribution transformers. In addition, the paper analyzes the effect of the system transient process on the calculation of the incremental impedance. The method has clear physics concept, can be easily implemented, and is practical for both linear and nonlinear load. Theoretical analysis, simulations, and experiments can verify the effectiveness of the method.
[1] IEEE Std. 1159—1995. Recommended practice for monitoring electric power quality[S]. 1995. [2] 李庚银, 杨晓东, 周明. 复杂配电网的电压暂降随机预估方法[J]. 电工技术学报, 2009, 24(11): 134-141. Li Gengyin, Yang Xiaodong, Zhou Ming. Stochastic estimation method of voltage sags in complex distribution systems[J]. Transactions of China Elec-trotechnical Society, 2009, 24(11): 134-141. [3] 林焱, 吴丹岳, 章雪萌, 等. 电压暂降指标的探讨[J]. 电力系统保护与控制, 2010, 38(3): 147-152. Lin Yan, Wu Danyue, Zhang Xuemeng, et al. An exploration on index about voltage sags[J]. Power System Protection and Control, 2010, 38(3): 147-152. [4] 雷刚, 顾伟, 袁晓冬. 考虑系统与敏感负荷兼容性的电压暂降指标[J]. 电工技术学报, 2010, 25(12): 132-138. Lei Gang, Gu Wei, Yuan Xiaodong. A voltage sag index considering compatibility between system and sensitive equipment[J]. Transactions of China Elec-trotechnical Society, 2010, 25(12): 132-138 [5] 陶顺, 肖湘宁, 刘晓娟. 电压暂降对配电系统可靠性影响及其评估指标的研究[J]. 中国电机工程学报, 2005, 25(21): 66-72. Tao Shun, Xiao Xiangning, Liu Xiaojuan. Study on distribution reliability considering voltage sags and acceptable indices[J]. Proceedings of the CSEE, 2005, 25(21): 66-72. [6] 吕干云, 孙维蒙, 汪晓东, 等. 电力系统电压暂降源定位方法综述[J]. 电力系统保护与控制, 2010, 38(23): 241-245. Lv Ganyun, Sun Weimeng, Wang Xiaodong, et al. Review on methods for voltage sag source location in power system[J]. Power System Protection and Control, 2010, 38(23): 241-245. [7] Parsons A C, Grady W M, Powers E J, et a1. A direction finder for power quality disturbances based upon disturbance power and energy[J]. IEEE Transactions on Power Delivery, 2000, 15(3): 1081-1086. [8] 张文涛, 王成山. 基于改进扰动功率和能量法的暂态扰动定位[J]. 电力系统自动化, 2007, 31(8): 31-34. Zhang Wentao, Wang Chengshan. Transient disturbances location based on improved disturbance power and energy[J]. Power System Technology, 2007, 31(8): 31-34. [9] Kong Wei, Dong Xinzhou, Chen Zhe. Voltage sag sourcelocation based on instantaneous energy detection[J]. Electric Power Systems Research, 2008, 78(3): 1889-1898. [10] Li C, Tayjasanant T, Xu W. Method for voltage sag source detection by investigating slope of the system trajectory[J]. IEEE Proceedings: Generation, Tran-smission and Distribution, 2003, 150(3)：367-372. [11] Pradhan A K, Routray A. Applying distance relay forvoltage sag source detection[J]. IEEE Transactions on Power Delivery, 2005, 20(3): 529-531. [12] 吕干云, 孙维蒙, 汪晓东, 等. 利用三点法的电压暂降源定位方法[J].中国电机工程学报, 2011, 31(7): 36-40. Lü Ganyun, Sun Weimeng, Wang Xiaodong, et al. Voltage sag source location based on three-point method[J]. Proceedings of the CSEE, 2011, 31(7): 36-40. [13] Tayjasanant Thavatchai, Li Chun, Xu Wilsun. Resistance sign-based method for voltage sag source detection[J]. IEEE Transactions on Power Delivery, 2005, 20(4): 25-44. [14] 朱珂, 徐文远. 基于等效阻抗理论的故障选线方法[J]. 电力自动化设备, 2007, 27(11): 18-21. Zhu Ke, Xu Wenyuan. Faulty line detection based on incremental impedance theory[J]. Electric Power Automation Equipment, 2007, 27(11): 18-21. [15] 楼书氢. 配电网中电压暂降源的识别与定位[D]. 北京: 华北电力大学, 2007. [16] 陶顺, 肖湘宁. 中性点不同接地方式下的电压暂降类型及其在变压器间的传递（二）[J]. 电工技术学报, 2007, 22(10): 156-159. Tao Shun, Xiao Xiangning. Voltage sags types under different grounding modes of neutral and their propagation: partⅡ[J]. Transactions of China Electrotechnical Society, 2007, 22(10): 156-159. [17] Gunther E W, Metha H. A study of distribution system power quality—preliminary results[J]. IEEE Transactions on Power Delivery, 1995, 10(1): 322-329. [18] Tang L, Lamoree J, Mcgranaghan, et al. Distribution system voltage sags: interaction with motor and drive loads[C]. Proceedings of IEEE Transmission and Distribution Conference, Chicago, USA, 1994: 1-6.
2015, Vol. 30 
