A Dynamic Evaluation Approach to the Security of Distribution Network with PV

doi:10.11985/2016.04.007

Abstract

Abstract:

In order to study the impact on distribution network caused by grid-connected photovoltaic (PV), the dynamic evaluation is used for evaluating the security of distribution. The index system of security assessment for distribution network with PV is established and OpenDSS software is used to simulate the volatility and randomness of PV power generation in the paper. The combination of superiority chart and entropy method is applied to gain comprehensive weights. Besides, the dynamic evaluation method is established based on fuzzy comprehensive assessment method and applied to the security evaluation of distribution network under different PV accessed capacity on the sunny day and cloudy day respectively. Also different power usage periods with different weights is assigned and second weighting is used to obtain the final evaluation results. The analysis examples indicate that the results by dynamic evaluation method are more close to the actual power usage.

Key words: Gird-connected PV, security, dynamic evaluation, index system, comprehensive weights

CLC Number:

TM727

Fan Ruonan,Bi Rui,Han Pingping. A Dynamic Evaluation Approach to the Security of Distribution Network with PV[J]. Journal of Electrical Engineering, 2016, 11(4): 41-46.

Figures/Tables 8

Tab.2

Fig.1

Fig.2

Fig.3

Tab.3

Fig.4

Tab.4

References 11

[1]	黄欣科, 王环, 王一波 , 等. 光伏发电系统并网点电压升高调整原理及策略[J]. 电力系统自动化, 2014,38(3):112-117. doi: 10.7500/AEPS20130228003
	Huang Xinke, Wang Huan, Wang Yibo , et al. Principle and strategies of voltage rise regulation for grid-connected photovoltaic generation system at point of common coupling[J]. Automation of Electric Power Systems, 2014,38(3):112-117. doi: 10.7500/AEPS20130228003
[2]	陈文, 崔一铂, 游力 . 分布式光伏电站对配电网电压的影响研究[J]. 湖北电力, 2013,37(9):32-35.
	Chen Wen, Cui Yibo, You Li . Research on the impact of distributed photovoltaic power on the voltage of distribution grid[J]. Hubei Electric Power, 2013,37(9):32-35.
[3]	马丽叶, 贾彬, 卢志刚 , 等. 基于静态安全性和实时供电能力的输电网安全等级研究[J]. 电工技术学报, 2014,29(6):229-237.
	Ma Liye, Jia Bin, Lu Zhigang , et al. Research on security classification of transmission network considering static security and real-time power supply capability[J]. Transactions of China Electrotechnical Society, 2014,29(6):229-237.
[4]	唐会智, 彭建春 . 基于模糊理论的电能质量综合量化指标研究[J]. 电网技术, 2003,27(12):85-88.
	Tang Huizhi, Peng Jianchun . Research on synthetic and quantified appraisal index of power quality based on fuzzy theory[J]. Power System Technology, 2003,27(12):85-88.
[5]	李鹏, 孙充勃, 王成山 , 等. 电网基于OpenDSS的智能配电网仿真与模拟平台及其应用[J]. 中国电力, 2013,46(11):12-16.
	Li Peng, Sun Chongbo, Wang Chengshan , et al. Open DSS-based simulation and modeling platform of smart distribution system and its application[J]. Electric Power, 2013,46(11):12-16.
[6]	裴玮, 盛鹍, 孔力 , 等. 分布式电源对配电网供电电压质量的影响和改善[J]. 中国电机工程学报, 2008,28(13):152-157.
	Pei Wei, Sheng Kun, Kong Li , et al. Impact and improvement of distributed generation on distribution network voltage quality[J]. Proceedings of the CSEE, 2008,28(13):152-157.
[7]	张国华, 张建华, 彭谦 , 等. 电网安全评价的指标体系与方法[J]. 电网技术, 2009,33(8):30-34.
	Zhang Guohua, Zhang Jianhua, Peng Qian , et al. Index system and methods for power grid security assessment[J]. Power System Technology, 2009,33(8):30-34.
[8]	肖辉耀, 姚建刚, 章建 , 等. 电网安全评估体系分析[J]. 电网技术, 2009,33(12):77-82.
	Xiao Yaohui, Yao Jiangang, Zhang Jian , et al. Analysis on power grid safety assessment system[J]. Power System Technology, 2009,33(12):77-82.
[9]	谢红卉, 毛建林 . 配电网安全性评价指标与方法研究[J]. 电力技术, 2011,10:39-41.
	Xie Honghui, Mao Jianlin . Research on security indices and method of distribution networks[J]. Electric Power Technology, 2011,10:39-41.
[10]	程启月 . 评测指标权重确定的结构熵权法[J]. 系统工程理论与实践, 2010,30(7):1225-1228.
	Cheng Qiyue . Structure entropy weight method to confirm the weight of evaluating index[J]. Systems Engineering-Theory & Practice, 2010,30(7):1225-1228.
[11]	刘怀东, 石世锋, 高天亮 , 等. 基于动态安全域的电力系统安全概率评估模型[J]. 中国电力, 2012,45(5):1-5.
	Liu Huaidong, Shi Shifeng, Gao Tianliang , et al. Probabilistic model of power system security assessment based on dynamic security region[J]. Electric Power, 2012,45(5):1-5.

一级指标	二级指标	说明
供电能力	正常运行率C₁	馈线负荷电流I与正常容许电流I_N之比,判别电流是否超出正常容许电流
	有功功率缓解度C₂	未接入光伏时某线路有功功率P与接入后有功功率P_PV之差比P,衡量光伏系统接入后对线路输送有功功率的缓解程度
	电压合格率C₃	某节点的实际运行电压在允许电压偏差范围内累计运行时间与对应总运行统计时间的百分比
	功率裕度系数C₄	临界点P_max与P之差比P,判断电网运行的薄弱地区
供电质量	电压波动率C₅	相邻两时刻电压V_a(t)、V_a(t-1)的差与前一时刻电压V_a(t-1)之比,体现光伏波动性对节点电压的影响
	电压变化率C₆	光伏接入后节点电压U_n′与未接入时电压U_n之差比U_n,体现光伏电源对节点电压的支撑作用
	网损率C₇	电能损耗量与总供电量的比值,高压电网网损率应控制在8%以下,低压电网网损率应控制在12%以下
	系统均衡度C₈	SE = ,H_i= S_L_i /S_LN_i,S_L_i、S_LN_i分别为线路i的实际功率和实时极限容量,反映电网线路潮流分布是否均衡

指标	C₁	C₂	C₃	C₄	C₅	C₆	C₇	C₈
主观权重	0.143	0	0.25	0.107	0.179	0.036	0.214	0.071
客观权重	0.351	0.316	0	0.335	0.278	0.245	0.242	0.234
复合权重	0.236	0	0	0.168	0.234	0.041	0.243	0.078