Optimal Scheduling Method for Distributed Photovoltaic Generation in Distribution Network Considering Power Quality Improvement

doi:10.12204/j.issn.1000-7229.2022.10.014

Abstract

Abstract:

Aiming at the problems of voltage violation, harmonic distortion and three-phase imbalance in distribution network, this paper studies the optimal scheduling model and its solution algorithm of distributed photovoltaic generation in distribution network from the perspective of comprehensively improving power quality. Firstly, the control scheme of reactive power, harmonic current and unbalanced power compensation of the grid-connected inverter of distributed photovoltaic generation is analyzed. On this basis, taking the three-phase power and harmonic current output of schedulable distributed photovoltaic generation as control variables, combined with the three-phase fundamental and harmonic power flow equations of distribution network, an optimal power flow model considering the improvement of power quality is established. Then, a two-stage optimization algorithm with alternating iteration of power flow calculation and optimization calculation is proposed to reduce the variables of the nonconvex nonlinear optimal power flow model and convert it into a convex quadratic constrained quadratic programming model, so as to achieve efficient solution. Finally, a case study is carried out on a 162-node three-phase distribution network. The results show that, after the scheduling of distributed photovoltaic generation according to the solution of optimal power flow model, the problems of harmonic distortion, three-phase imbalance and voltage violation of distribution network have been effectively improved, and the computational efficiency of the two-stage optimization algorithm also meets the distribution network scheduling requirements, which verifies the effectiveness of the proposed optimal scheduling method for distributed photovoltaic generation in improving the power quality of distribution network.

Key words: distribution network, power quality, distributed photovoltaic generation, optimal scheduling

CLC Number:

TM732

ZHANG Min, ZHI Huiqiang, ZHANG Shifeng, FAN Rui, LI Ran, WANG Jinhao. Optimal Scheduling Method for Distributed Photovoltaic Generation in Distribution Network Considering Power Quality Improvement[J]. ELECTRIC POWER CONSTRUCTION, 2022, 43(10): 147-157.

Figures/Tables 21

Fig.1 Structure of single-phase distributed photovoltaic generation system

Fig.2 Diagram of DC-voltage outer loop

Fig.3 Diagram of current inner loop

Fig.4 Structure of three-phase distributed photovoltaic generation system

Fig.5 Diagram of power outer loop

Fig.6 Voltage magnitude constraints in rectangular coordinate

Fig.7 Structure of the test distribution network

Fig.8 Total load and total PV generation of low voltage network

Table 1 Basic information of the case

Fig.9 Output of SDPV at 12:00

Fig.10 Output of SDPV at 20:00

Table 2 Voltage at node 107 before and after optimization

Fig.11 Daily change of node voltage magnitude

Fig.12 Daily change of active power loss

Fig.13 Daily change of the maximum imbalance degree caused by negative sequence voltage

Fig.14 Daily change of maximum total harmonic distortion rate of voltage

Table 3 The optimal results under different weight coefficients

Fig.15 Variation range of phase angle of each-phase node voltage

Fig.16 Error analysis process of the proposed optimization algorithm

Table 4 Model errors under different iterations

Fig.17 Total time-cost of the proposed two-stage optimization algorithm

References 26

[1]	李桂鑫, 徐科, 刘英英, 等. 基于分布式模型预测控制的含分布式储能有源配电网动态电压控制[J]. 电力建设, 2021, 42(6): 116-126. doi: 10.12204/j.issn.1000-7229.2021.06.012
	LI Guixin, XU Ke, LIU Yingying, et al. Dynamic voltage control based on DMPC for active distribution network with distributed energy storage systems[J]. Electric Power Construction, 2021, 42(6): 116-126. doi: 10.12204/j.issn.1000-7229.2021.06.012
[2]	刘科研, 贾东梨, 王薇嘉, 等. 考虑分布式光伏电源接入模式的低压配电网不平衡线损计算方法[J]. 电力建设, 2021, 42(10): 129-138. doi: 10.12204/j.issn.1000-7229.2021.10.014
	LIU Keyan, JIA Dongli, WANG Weijia, et al. Calculation method of unbalanced line loss in low-voltage distribution network considering the access mode of distributed photovoltaic generation[J]. Electric Power Construction, 2021, 42(10): 129-138. doi: 10.12204/j.issn.1000-7229.2021.10.014
[3]	张孟琛, 林丽娟, 孟菁, 等. 数据驱动的配电台区源荷污染源群体谐波排放建模[J]. 电力建设, 2021, 42(8): 46-54. doi: 10.12204/j.issn.1000-7229.2021.08.006
	ZHANG Mengchen, LIN Lijuan, MENG Jing, et al. Data-driven harmonic modeling for distribution area in distribution networks with distributed harmonic loads[J]. Electric Power Construction, 2021, 42(8): 46-54. doi: 10.12204/j.issn.1000-7229.2021.08.006
[4]	王晓, 罗安, 邓才波, 等. 基于光伏并网的电能质量控制系统[J]. 电网技术, 2012, 36(4): 68-73.
	WANG Xiao, LUO An, DENG Caibo, et al. A power quality control system based on grid-connected photovoltaic power generation[J]. Power System Technology, 2012, 36(4): 68-73.
[5]	靳伟, 李永丽, 卜立之, 等. 基于CPT理论和重复控制的多功能并网逆变器研究[J]. 电工技术学报, 2018, 33(18): 4345-4356.
	JIN Wei, LI Yongli, BU Lizhi, et al. Research on multi-functional grid-connected inverters based on conservative power theory and repetitive control[J]. Transactions of China Electrotechnical Society, 2018, 33(18): 4345-4356.
[6]	许晓艳, 黄越辉, 刘纯, 等. 分布式光伏发电对配电网电压的影响及电压越限的解决方案[J]. 电网技术, 2010, 34(10): 140-146.
	XU Xiaoyan, HUANG Yuehui, LIU Chun, et al. Influence of distributed photovoltaic generation on voltage in distribution network and solution of voltage beyond limits[J]. Power System Technology, 2010, 34(10): 140-146.
[7]	路怡, 江道灼, 梁一桥, 等. 一种抑制含光伏电源配电网电压越限的方法[J]. 电力建设, 2020, 41(11): 87-93. doi: 10.12204/j.issn.1000-7229.2020.11.009
	LU Yi, JIANG Daozhuo, LIANG Yiqiao, et al. A method for suppressing voltage beyond limits in distribution network with photovoltaic power sources[J]. Electric Power Construction, 2020, 41(11): 87-93. doi: 10.12204/j.issn.1000-7229.2020.11.009
[8]	刘蕊, 吴奎华, 冯亮, 等. 含高渗透率分布式光伏的主动配电网电压分区协调优化控制[J]. 太阳能学报, 2022, 43(2): 189-197.
	LIU Rui, WU Kuihua, FENG Liang, et al. Voltage partition coordinated optimization control of active distribution network of high penetration distributed PVs[J]. Acta Energiae Solaris Sinica, 2022, 43(2): 189-197.
[9]	李克强, 韩学山, 李华东, 等. 配网中光伏逆变器最优潮流追踪的分布式算法[J]. 中国电机工程学报, 2019, 39(3): 711-720, 950.
	LI Keqiang, HAN Xueshan, LI Huadong, et al. Distributed algorithm for optimal power flow pursuit by photovoltaic inverters in distribution systems[J]. Proceedings of the CSEE, 2019, 39(3): 711-720, 950.
[10]	郑能, 丁晓群, 郑程拓, 等. 含高比例光伏的配电网有功-无功功率多目标协调优化[J]. 电力系统自动化, 2018, 42(6): 33-39, 91.
	ZHENG Neng, DING Xiaoqun, ZHENG Chengtuo, et al. Multi-objective coordinated optimization of active and reactive power for distribution network integrated with high proportion of photovoltaic generation[J]. Automation of Electric Power Systems, 2018, 42(6): 33-39, 91.
[11]	陈家超, 李钦豪, 唐渊, 等. 考虑光伏选相投切的低压配电网三相平衡优化[J]. 电力自动化设备, 2022, 42(4): 71-78.
	CHEN Jiachao, LI Qinhao, TANG Yuan, et al. Three-phase balance optimization of low-voltage distribution network considering photovoltaic phase selection and switching[J]. Electric Power Automation Equipment, 2022, 42(4): 71-78.
[12]	蔡永翔, 唐巍, 张博, 等. 适应高比例户用光伏的中低压配电网集中-分布式协调控制[J]. 中国电机工程学报, 2020, 40(15): 4843-4854.
	CAI Yongxiang, TANG Wei, ZHANG Bo, et al. Centralized-distributed multi-objective coordinated control for MV and LV distribution networks adapting to high-proportion residential PV units[J]. Proceedings of the CSEE, 2020, 40(15): 4843-4854.
[13]	SU X J, MASOUM M A S, WOLFS P J. Optimal PV inverter reactive power control and real power curtailment to improve performance of unbalanced four-wire LV distribution networks[J]. IEEE Transactions on Sustainable Energy, 2014, 5(3): 967-977. doi: 10.1109/TSTE.2014.2313862 URL
[14]	GUGGILAM S S, DALL’ANESE E, CHEN Y C, et al. Scalable optimization methods for distribution networks with high PV integration[J]. IEEE Transactions on Smart Grid, 2016, 7(4): 2061-2070. doi: 10.1109/TSG.2016.2543264 URL
[15]	FARIVAR M, LOW S H. Branch flow model: Relaxations and convexification—part I[J]. IEEE Transactions on Power Systems, 2013, 28(3): 2554-2564. doi: 10.1109/TPWRS.2013.2255317 URL
[16]	涂辉, 周建聪, 石文超, 等. 考虑多种调节手段的配电网经济运行优化[J]. 电力建设, 2018, 39(8): 42-52. doi: 10.3969/j.issn.1000-7229.2018.08.006
	TU Hui, ZHOU Jiancong, SHI Wenchao, et al. Economical operation optimization of distribution network considering multiple adjustment measures[J]. Electric Power Construction, 2018, 39(8): 42-52.
[17]	LIU Y, LI J, WU L. ACOPF for Three-phase four-conductor distribution systems: semidefinite programming based relaxation with variable reduction and feasible solution recovery[J]. IET Generation, Transmission & Distribution, 2019, 13(2): 266-276. doi: 10.1049/iet-gtd.2018.5033 URL
[18]	NGUYEN Q, PADULLAPARTI H V, LAO K W, et al. Exact optimal power dispatch in unbalanced distribution systems with high PV penetration[J]. IEEE Transactions on Power Systems, 2019, 34(1): 718-728. doi: 10.1109/TPWRS.2018.2869195 URL
[19]	禹威威, 刘世林, 陈其工, 等. 考虑需求侧管理的光伏微电网多目标优化调度方法[J]. 太阳能学报, 2017, 38(11): 2972-2981.
	YU Weiwei, LIU Shilin, CHEN Qigong, et al. Multi-objective optimization scheduling method for photovoltaic based microgrid considering demand side management[J]. Acta Energiae Solaris Sinica, 2017, 38(11): 2972-2981.
[20]	艾永乐, 丁剑英, 刘群峰, 等. 计及负荷需求响应的并网家用光伏系统协同优化调度[J]. 太阳能学报, 2021, 42(9): 104-114.
	AI Yongle, DING Jianying, LIU Qunfeng, et al. Synergetic optimal scheduling of grid-connected household photovoltaic system considering demand response for loads[J]. Acta Energiae Solaris Sinica, 2021, 42(9): 104-114.
[21]	DALL’ANESE E, DHOPLE S V, GIANNAKIS G B. Optimal dispatch of photovoltaic inverters in residential distribution systems[J]. IEEE Transactions on Sustainable Energy, 2014, 5(2):487-497. doi: 10.1109/TSTE.2013.2292828 URL
[22]	寇凌峰, 吴鸣, 李洋, 等. 主动配电网分布式有功无功优化调控方法[J]. 中国电机工程学报, 2020, 40(6): 1856-1865.
	KOU Lingfeng, WU Ming, LI Yang, et al. Optimization and control method of distributed active and reactive power in active distribution network[J]. Proceedings of the CSEE, 2020, 40(6): 1856-1865.
[23]	陈厚合, 刘丽娜, 姜涛, 等. 提升配电网电压质量的分布式储能经济优化配置方法[J]. 电网技术, 2018, 42(7): 2127-2135.
	CHEN Houhe, LIU Lina, JIANG Tao, et al. Optimal economic configuration of distributed energy storage systems for improving voltage quality in distribution network[J]. Power System Technology, 2018, 42(7): 2127-2135.
[24]	刘天琪, 邱晓燕, 李华强. 现代电力系统分析理论与方法[M]. 北京: 中国电力出版社, 2007.
[25]	BU F K, YUAN Y X, WANG Z Y, et al. A time-series distribution test system based on real utility data[C]// 2019 North American Power Symposium (NAPS). Wichita, KS, USA: IEEE, 2019: 1-6.
[26]	WANG Y, YONG J, SUN Y Y, et al. Characteristics of harmonic distortions in residential distribution systems[J]. IEEE Transactions on Power Delivery, 2017, 32(3): 1495-1504. doi: 10.1109/TPWRD.2016.2606431 URL