Abstract In this paper, a radial sub-network of a given distribution network is chosen as a tree, and two types of loops, i.e. 1st loops and 2nd loops, are built according to two kinds of links. Then the loop current and load node voltage equations are set up. Thus the loop currents and load node voltages are explicitly related, and the network loop impedance matrix and node load equivalent impedance matrix are clearly separated. Based on the proposed network equations, direct solution methods and a back/forward sweep method are designed and applied to several IEEE cases. Two techniques are used to deal with the single-phase zero load loops. One is that loads are equivalent as admittances, and the other is that zero-load loop equations are eliminated. As a result, the proposed back/forward sweep can calculate loop currents directly according to the node loads and node voltages, which enhances the efficiency greatly.
[1] 王守相, 王成山. 现代配电系统分析[M]. 北京: 高等教育出版社, 2007. [2] 张丽, 徐玉琴, 王增平, 等. 包含分布式电源的配电网无功优化[J]. 电工技术学报, 2011, 26(3): 168-174. Zhang Li, Xu Yuqin, Wang Zengping, et al. Reactive power optimization for distribution system with distributed generators[J]. Transactions of China Electrotechnical Society, 2011, 26(3): 168-174. [3] 康忠健, 訾淑伟. 基于差分进化算法的油田区域配电网无功优化技术的研究[J]. 电工技术学报, 2013, 28(6): 226-231. Kang Zhongjian, Zi Shuwei. Research on the reactive power optimization of oil-field regional distribution network based on differential evolution[J]. Transa- ctions of China Electrotechnical Society, 2013, 28(6): 226-231. [4] 靳小龙, 穆云飞, 贾宏杰, 等. 面向最大供电能力提升的配电网主动重构策略[J]. 电工技术学报, 2014, 29(12): 137-147. Jin Xiaolong, Mu Yunfei, Jia Hongjie, et al. An active reconfiguration strategy for distribution network based on maximum power supply capability[J]. Transactions of China Electrotechnical Society, 2014, 29(12): 137-147. [5] 车仁飞, 李仁俊. 一种少环配电网三相潮流计算新方法[J]. 中国电机工程学报, 2003, 23(1): 74-79. Che Renfei, Li Renjun. A new three-phase power flow method for weakly meshed distribution systems[J]. Proceedings of the CSEE, 2003, 23(1): 74-79. [6] 杨辉, 文福拴, 刘永强, 等. 适用于配电系统潮流计算的新的前推回代算法[J]. 电力系统及其自动化学报, 2010, 22(3): 123-128. Yang Hui, Wen Fushuan, Liu Yongqiang, et al. New back/forward sweep method for load flow com- putation in distribution systems[J]. Proceedings of the CSU-EPSA, 2010, 22(3): 123-128. [7] Luo G X, Semlyen A. Efficient load flow for large weakly meshed networks[J]. IEEE Transactions on Power Systems, 1990, 5(4): 1309-1316. [8] Chang G, Chu S Y, Hsu M F, et al. An efficient power flow algorithm for weakly meshed distribution systems[J]. Electric Power Systems Research, 2012, 5(4): 1309-1316. [9] 胡晓松, 张殷, 谢光彬, 等. 含PV节点的配电网合环潮流算法[J]. 电力系统保护与控制, 2015, 43(24): 8-13. Hu Xiaosong, Zhang Yin, Xie Guangbin, et al. A loop closing power flow calculation algorithm of distri- bution network with PV nodes[J]. Power System Protection and Control, 2015, 43(24): 8-13. [10] 王振树, 林梅军, 刘岩, 等. 考虑光伏并网的配电网潮流计算[J]. 电工技术学报, 2013, 28(9): 178- 185. Wang Zhenshu, Lin Meijun, Liu Yan, et al. Power flow algorithm for distribution network with photo- voltaic system[J]. Transactions of China Electro- technical Society, 2013, 28(9):178-185. [11] 蔡中勤, 郭志忠. 基于逆流编号法的辐射型配电网牛顿法潮流[J]. 中国电机工程学报, 2000, 20(6): 13-16. Cai Zhongqin, Guo Zhizhong. Newton load flow for radial distribution network based on upstream labeling technique[J]. Proceedings of the CSEE, 2000, 20(6): 13-16. [12] 张荣, 王秀和, 付大金, 等. 改进的带二阶项配电网快速潮流算法[J]. 电工技术学报, 2004, 19(7): 59-64. Zhang Rong, Wang Xiuhe, Fu Dajin, et al. Improved algorithm for fast distribution power flow calculation including second order term[J]. Transactions of China Electrotechnical Society, 2004, 19(7): 59-64. [13] 张立梅, 唐巍. 计及分布式电源的配电网前推回代潮流计算[J]. 电工技术学报, 2010, 25(8): 123-130. Zhang Limei, Tang Wei. Back/forward sweep power flow calculation method of distribution networks with DGs[J]. Transactions of China Electrotechnical Society, 2010, 25(8): 123-130. [14] Wu W C, Zhang B M. A three-phase power flow algorithm for distribution system power flow based on loop-analysis method[J]. Electrical Power Energy Systems, 2008, 30: 8-15. [15] 李宏伟, 孙宏斌, 张安安, 等. 基于正序分量的含PV节点的三相配网潮流算法[J]. 中国电机工程学报, 2012, 32(1): 115-121. Li Hongwei, Sun Hongbin, Zhang Anan, et al. Positive-sequence component based three-phase unbalanced power flow solution for distribution system with PV nodes[J]. Proceedings of the CSEE, 2012, 32(1): 115-121. [16] Goswami S K, Basu S K. Direct solution of distribution systems[J]. IEE Proceedings of Gener- ation Transmission & Distribution (Part C), 1991, 138 (1): 78-88. [17] Teng J H. A direct approach for distribution system load flow solutions[J]. IEEE Transactions on Power Delivery, 2003, 18(3): 882-887. [18] 汪宇霆, 张焰, 张益波. 基于改进回路电流法的配电网潮流通用算法[J]. 电力系统保护与控制, 2010, 38(20): 57-61. Wang Yuting, Zhang Yan, Zhang Yibo. A general load flow method for distribution systems based on improved load-current method[J]. Power System Protection and Control, 2010, 38(20): 57-61.
2016, Vol. 31 
