摘要
针对支路故障率时变性、谐波含量不确定性以及随机变量存在相关性影响极限线损准确计算的问题,结合柔性互联配电网的计算需求,提出一种计及多重不确定因素的极限线损计算方法。首先采用改进三段式Weibull分布拟合支路故障率,并建立支路故障率的概率分布模型,结合全概率公式求解考虑支路故障率时变性的损耗概率分布。然后建立网架变化时换流器谐波含有率随传输功率变化的关联模型,解决确定谐波无法体现谐波波动对线损标准差的影响的问题。其次为量化随机变量相关性对极限线损的影响,引入Nataf逆变换对三点估计法进行改进,并结合故障率概率模型和谐波含量关联模型,构建多重不确定因素下极限线损的计算方法。最后改进IEEE 33节点系统算例结果表明所提算法准确性高,计算速度快。
Aiming at the problems that the time-varying branch fault rate, the uncertainty of harmonic content and the correlation of random variables affect the accurate calculation of limit line loss, combined with the calculation requirements of flexible interconnected distribution network, a limit line loss calculation method considering multiple uncertain factors is proposed in this paper. Firstly, the improved three-stage Weibull distribution is used to fit the branch failure rate, and the probability distribution model of branch failure rate is established. Combined with the full probability formula, the loss probability distribution considering the time-varying of branch failure rate is solved. Then, the correlation model of the harmonic content of the converter with the transmission power is established to solve the problem that the harmonic can’t reflect the influence of harmonic fluctuation on the standard deviation of line loss. Secondly,in order to quantify the influence of the correlation of random variables on the limit line loss, the Nataf inverse transform is introduced to improve the three-point estimation method, and combined with the failure rate probability model and harmonic content correlation model, the calculation method of limit line loss under multiple uncertain factors is constructed. Finally, an example of improved IEEE 33 node system shows that the proposed algorithm has high accuracy and fast calculation speed.
作者
张真
欧阳森
杨墨缘
吴晗
ZHANG Zhen;OUYANG Sen;YANG Moyuan;WU Han(School of Electric Power Engineering,South China University of Technology,Guangzhou 510640,China)
出处
《南方电网技术》
CSCD
北大核心
2022年第12期88-97,共10页
Southern Power System Technology
基金
中央高校基本科研业务费重大产学研合作扶持专项(x2dlD2201280)
国家自然科学基金资助项目(51677073)。
关键词
柔性互联配电网
极限线损
谐波
故障率
三点估计法
flexible interconnected distribution network
limit line loss
harmonics
failure rate
three-point estimation method
