Power Flow Calculation of DC Distribution Network Based on the Retaining-nonlinearity Algorithm

doi:10.11985/2020.04.009

Abstract

Abstract:

With the increase of DC load and DC power source, DC power supply system will become the future development direction of distribution system. In order to calculate the power flow distribution of the DC distribution network, the steady-state model and control method of the voltage-sourced converter are analyzed, and the unified steady-state non-ideal model of the DC-DC converter is established. Based on the above analysis, a power flow calculation method of DC distribution network based on retaining-nonlinearity algorithm is proposed. To solve the problem that the retaining-nonlinearity algorithm requires high initial value, a method using the solution of linear power flow algorithm as the initial value is proposed, which greatly reduced the number of iterations. The proposed algorithm improved the speed of power flow calculation while ensuring accuracy. Taking the 30-node DC distribution network model as an example for analysis and the results are compared with the solution of Newton-Raphson algorithm, the advantage of retaining-nonlinearity algorithm in the calculation speed is verified.

Key words: Retaining-nonlinearity, DC distribution network, power flow calculation, DC-DC converter, steady-state non-ideal model

CLC Number:

TM744

DIAO Shoubin, YU Tao, WANG Jianjian, AN Peng, LI Xinpeng. Power Flow Calculation of DC Distribution Network Based on the Retaining-nonlinearity Algorithm[J]. Journal of Electrical Engineering, 2020, 15(4): 75-84.

Figures/Tables 20

References 28

[1]	张敬安, 王雷涛, 王鹏. 交直流混合配电网电能质量综合检测和补偿方法[J]. 电气工程学报, 2018,13(9):38-43.
	ZHANG Jingan, WANG Leitao, WANG Peng. Power quality detection and compensation method of AC/DC hybrid distribution network[J]. Journal of Electrical Engineering, 2018,13(9):38-43.
[2]	安海清, 岳娜, 李振动, 等. 配电网中谐波传递特性研究[J]. 电气工程学报, 2019,14(2):86-91. doi: 10.11985/2019.02.015
	AN Haiqing, YUE Na, LI Zhendong, et al. Research on harmonic transfer characteristics in distribution network[J]. Journal of Electrical Engineering, 2019,14(2):86-91.
[3]	曾嘉思, 徐习东, 赵宇明. 交直流配电网可靠性对比[J]. 电网技术, 2014,38(9):2582-2589. doi: 10.13335/j.1000-3673.pst.2014.09.042
	ZENG Jiasi, XU Xidong, ZHAO Yuming. Reliability comparison of AC and DC distribution network[J]. Power Grid Technology, 2014,38(9):2582-2589.
[4]	郑欢, 江道灼, 杜翼. 交流配电网与直流配电网的经济性比较[J]. 电网技术, 2013,37(12):3368-3374.
	ZHENG Huan, JIANG Daozhuo, DU Yi. Economic comparison of AC and DC distribution system[J]. Power Grid Technology, 2013,37(12):3368-3374.
[5]	李霞林, 郭力, 王成山, 等. 直流微电网关键技术研究综述[J]. 中国电机工程学报, 2016,36(1):2-17. doi: 10.13334/j.0258-8013.pcsee.2016.01.001
	LI Xialin, GUO Li, WANG Chengshan, et al. Key technologies of DC microgrids:An overview[J]. Proceedings of the CSEE, 2016,36(1):2-17.
[6]	宋强, 赵彪, 刘文华, 等. 智能直流配电网研究综述[J]. 中国电机工程学报, 2013,33(25):9-19.
	SONG Qiang, ZHAO Biao, LIU Wenhua, et al. An overview of research on smart DC distribution power network[J]. Proceedings of the CSEE, 2013,33(25):9-19.
[7]	马钊, 赵志刚, 孙媛媛, 等. 新一代低压直流供用电系统关键技术及发展展望[J]. 电力系统自动化, 2019,43(23):12-22.
	MA Zhao, ZHAO Zhigang, SUN Yuanyuan, et al. Key technologies and development prospect of new generation low-voltage DC power supply and utilization system[J]. Automation of Electric Power Systems, 2019,43(23):12-22.
[8]	张朝学, 邹晓松, 余梦天, 等. 基于电压下垂控制的含MMC直流电网潮流计算方法研究[J]. 电力科学与工程, 2018,34(11):1-7.
	ZHANG Chaoxue, ZOU Xiaosong, YU Mengtian, et al. Research on power flow calculation method based on voltage sagging for containing MMC DC power systems[J]. Electric Power Science and Engineering, 2018,34(11):1-7.
[9]	和敬涵, 李智诚, 王小君, 等. 计及多种控制方式的直流电网潮流计算方法[J]. 电网技术, 2016,40(3):712-718.
	HE Jinghan, LI Zhicheng, WANG Xiaojun, et al. Power flow algorithom for DC grid considering various control modes[J]. Power Grid Technology, 2016,40(3):712-718.
[10]	WANG W Y, BARNES M. Power flow algorithms for multi-terminal VSC-HVDC with droop control[J]. IEEE Transactions on Power Systems, 2014,29(4):1721-1730.
[11]	解大, 喻松涛, 陈爱康, 等. 基于下垂特性调节的直流配电网稳态分析[J]. 中国电机工程学报, 2018,38(12):3516-3528,11.
	XIE Da, YU Songtao, CHEN Aikang, et al. Steady-state analysis for the DC distribution network with droop-control[J]. Proceedings of the CSEE, 2018,38(12):3516-3528,11.
[12]	HUSNAA W N, SIRAJ S F, MUIN M Z A. Modeling of DC-DC converter for solar energy system applications[C]// 2012 IEEE Symposium on Computers & Informatics(ISCI),Penang,Malaysia, 2012: 125-129.
[13]	BAHRAVAS, MAHERY H M, BABAEI E, et al. Mathematical modeling and transient analysis of DC-DC buck-boost converter in CCM[C]// IEEE 5th India International Conference on Power Electronics (IICPE),Delhi,India, 2012: 1-6.
[14]	张卫平, 关晓菡, 刘元超, 等. DC-DC 变换器稳态建模的教学方法[J]. 电气电子教学学报, 2008,30(5):101-104.
	ZHANG Weiping, GUAN Xiaohan, LIU Yuanchao, et al. Teaching method of building steady state models for DC-DC converters[J]. Journal of Electrical and Electronic Education, 2008,30(5):101-104.
[15]	李韦姝. 直流配电网潮流计算模型及算法研究[D]. 保定:华北电力大学, 2015.
	LI Weishu. Research on model and algorithm of power flow calculation in DC distribution network[D]. Baoding:North China Electric Power University, 2015.
[16]	孙银锋, 吴学光, 汤广福, 等. 基于节点阻抗矩阵GS法的直流电网稳态潮流计算[J]. 中国电机工程学报, 2015,35(8):1882-1892.
	SUN Yinfeng, WU Xueguang, TANG Guangfu, et al. A nodal impedance matrix based Gauss-Seidel method on steady state power flow calculation of DC power grid[J]. Proceedings of the CSEE, 2015,35(8):1882-1892.
[17]	钱甜甜, 苗世洪. 基于节点电流关系的多端柔性直流输电系统潮流计算[J]. 电网技术, 2016,40(5):1308-1312.
	QIAN Tiantian, MIAO Shihong. Power flow algorithm of multi-terminal VSC-HVDC system based on nodal current relation[J]. Power Grid Technology, 2016,40(5):1308-1312.
[18]	吴红斌, 杨超, 陈煜, 等. 基于电压源型换流器的多端直流配电网潮流计算[J]. 电力系统自动化, 2018,42(11):79-85,93.
	WU Hongbin, YANG Chao, CHEN Yu, et al. VSC based power flow calculation of multi-terminal DC distribution network[J]. Automation of Electric Power Systems, 2018,42(11):79-85,93.
[19]	WU L L, FAN X W, XU M, et al. Research and application of a power-flow-calculation method in multiterminal VSC-HVDC power grid[J]. Global Energy Interconnection, 2019,2(1):37-44. doi: 10.1016/j.gloei.2019.06.005
[20]	GAO S L, YE H, DU Y L, et al. A general decoupled AC/DC power flow algorithm with VSC-MTDC[C]// Proceedings of the 2018 13th IEEE Conference on Industrial Electronics and Applications(ICIEA 2018),Wuhan,China, 2018: 1779-1784.
[21]	MONTOYAO D GRISALES-NORENA L F GONZALEZ-MONTOYA D, et al. Linear power flow formulation for low-voltage DC power grids[J]. Electric Power Systems Research, 2018,163:375-381.
[22]	YUAN Z, WANG Y, YI Y, et al. Fast linear power flow algorithm for the study of steady-state performance of DC grid[J]. IEEE Transactions on Power Systems, 2019,34(6):4240-4248. doi: 10.1109/TPWRS.59
[23]	寇秋红, 李宝国, 鲁宝春. 一种改进的电力系统保留非线性潮流算法[J]. 辽宁工业大学学报, 2008(1):10-12.
	KOU Qiuhong, LI Baoguo, LU Baochun. Improvement of retaining-nonlinearity load flow algorithm[J]. Journal of Liaoning University of Technology, 2008(1):10-12.
[24]	秦孜. 改进非线性潮流算法在区域电网中的应用研究[D]. 淮南:安徽理工大学, 2019.
	QIN Zi. Application research of improved nonlinear power flow algorithm in regional power grid[D]. Huainan:Anhui University of Science and Technology, 2019.
[25]	侯博渊, 张荣祥. 保留非线性的快速P-Q解耦潮流计算法[J]. 电机工程学报, 1984(1):22-27.
	HOU Boyuan, ZHANG Rongxiang. The method of fast P-Q decoupled load flow calculation retaining non-linearity[J]. Proceedings of the CSEE, 1984(1):22-27.
[26]	FAN S X, LIU X W, YANG Y H, et al. Power flow calculation method for DC distribution system with voltage source converter operation mode consideration[C]// 3rd International Conference on Energy Engineering and Environmental Protection (EEEP),Sanya,China, 2018.
[27]	刘天琪. 现代电力系统分析理论与方法[M]. 北京:中国电力出版社, 2016.
	LIU Tianqi. Theory and method of modern power system analysis[M]. Beijing:China Electric Power Press, 2016.
[28]	ZHANG D, FU Z C, ZHANG L C. An improved TS algorithm for loss-minimum reconfiguration in large-scale distribution systems[J]. Electric Power Systems Research, 2007,77(5):685-694. doi: 10.1016/j.epsr.2006.06.005

支路	控制方式	模块数N
4-12	恒变比D=0.350	3
6-9	恒变比D=0.367	3
6-10	恒变比D=0.364	3
28-27	恒变比D=0.370	3

节点号	负荷功率/p.u.	电压/p.u.
1	0	1.050
11	0	1.010
13	0	1.010

节点	发电功率/p.u.	负荷功率/p.u.	节点	发电功率/p.u.	负荷功率/p.u.
2	0.8	0.217 0	18	0	0.003 2
3	0	0.024 0	19	0	0.009 5
4	0	0.076 0	20	0	0.002 2
5	0.5	0.942 0	21	0	0.017 5
6	0	0	22	0	0
7	0	0.228 0	23	0	0.003 2
8	0.2	0.300 0	24	0	0.008 7
9	0	0	25	0	0
10	0	0.005 8	26	0	0.003 5
12	0	0.011 2	27	0	0
14	0	0.006 2	28	0	0
15	0	0.008 2	29	0	0.002 4
16	0	0.003 5	30	0	0.010 6
17	0	0.009 0

支路	电阻/p.u.	支路	电阻/p.u.
1-2	0.019 2	12-13	0.064 0
1-3	0.045 2	12-14	0.123 1
2-4	0.057 0	12-15	0.066 2
2-5	0.047 2	12-16	0.094 5
2-6	0.058 1	14-15	0.221 0
3-4	0.013 2	15-18	0.107 3
4-6	0.011 9	15-23	0.100 0
4-12	0	16-17	0.052 4
5-7	0.046 0	18-19	0.063 9
6-7	0.026 7	19-20	0.064 0
6-8	0.012 0	21-22	0.061 6
6-9	0	22-24	0.115 0
6-10	0	23-24	0.132 0
6-28	0.016 9	24-25	0.188 5
8-28	0.063 6	25-26	0.254 4
9-10	0.071 0	25-27	0.109 3
9-11	0.070 8	27-29	0.219 8
10-17	0.052 4	27-30	0.320 2
10-20	0.093 6	28-27	0
10-21	0.054 8	29-30	0.239 9
10-22	0.072 7

节点	NR电压/p.u.	RN电压/p.u.
1	1.050 000 00	1.050 000 00
2	1.047 703 41	1.047 703 38
3	1.042 522 51	1.042 522 48
4	1.040 642 69	1.040 642 67
5	1.029 352 94	1.029 352 92
6	1.038 208 94	1.038 208 92
7	1.031 221 23	1.031 221 21
8	1.037 186 36	1.037 186 33
9	1.006 975 99	1.006 975 99
10	1.004 067 35	1.004 067 35
11	1.010 000 00	1.010 000 00
12	1.005 662 02	1.005 662 02
13	1.010 000 00	1.010 000 00
14	1.004 609 64	1.004 609 64
15	1.004 084 23	1.004 084 23
16	1.004 510 04	1.004 510 04
17	1.004 053 85	1.004 053 85
18	1.003 294 08	1.003 294 08
19	1.003 027 33	1.003 027 33
20	1.003 366 33	1.003 366 33
21	1.003 167 86	1.003 167 86
22	1.003 231 35	1.003 231 35
23	1.003 016 17	1.003 016 17
24	1.002 027 47	1.002 027 47
25	1.000 278 89	1.000 278 88
26	0.999 387 94	0.999 387 94
27	0.999 647 77	0.999 647 77
28	1.037 898 65	1.037 898 63
29	0.998 309 24	0.998 309 24
30	0.997 425 05	0.997 425 04