摘要
针对微电网时序多态不确定性带来的可靠性评估收敛缓慢的问题,提出了选择性数据驱动算法。首先,定义了单位区间上的系列连续随机变量,以其概率分布特性反映光储微电网元件及负荷的时序多态不确定性;其次,通过将可靠性指标表示为系列连续随机变量在超立方体范围内的积分函数,建立了兼容时序蒙特卡罗模拟的可靠性评估多维积分模型;再次,以方差最小为目标,基于拉格朗日乘子法得到了最优概率密度函数解析式,并运用蒙特卡罗积分法估计解析式的数值解;同时,定义了密度方差指标,定量评价各随机变量对可靠性评估计算费用的贡献;最后,提出选择性数据驱动算法,将可靠性评估过程分为选择性数据驱动和高效仿真评估两个阶段,通过选择性数据驱动确定主导随机变量及其最优密度函数,形成数据驱动策略,支撑高效仿真评估阶段的可靠性分析。在MATLAB环境下编制了相应的可靠性评估程序并开展了算例分析,结果表明:系统条件变化会导致主导随机变量迁移,选择性数据驱动算法能够确定主导随机变量并形成有效的数据驱动策略,大幅降低可靠性评估的计算费用。
Aiming at the heavy computational burden in reliability assessment of microgrid(MG),a selective data-driven algorithm(SDDA)is proposed.Firstly,a series of continuous random variables with proper probabilistic performances are defined to model the sequential multi-state uncertainties of components and load of MG.Secondly,the reliability index is expressed as the multidimensional integration in terms of random variables,which is compatible with sequential Monte Carlo(SMC)simulation.In addition,the analytical expressions of optimal probability density functions(PDFs)of random variables are worked out based on the Lagrange multiplier method,and the numerical solutions are estimated by Monte Carlo integration.At the same time,a density variance index is defined to evaluate the contribution of each random variable to the computation cost.Lastly,the SDDA is proposed to overcome the prohibitive computational burden by assigning selective data-driven procedure to determine the dominant variables and optimal PDFs,and efficient simulation procedure to decrease computation burden.An evaluation program based on SDDA is coded on the platform of MATLAB,and comprehensive case studies are implemented.Results show that dominant random variables will change along with system conditions and be identified by SDDA,which will propose an effective data-driven strategy accordingly.Then the computation cost of reliability assessment is greatly reduced.
作者
宋晓通
徐文悦
周京华
孙艺
郑伟杰
SONG Xiaotong;XU Wenyue;ZHOU Jinghua;SUN Yi;ZHENG Weijie(College of Electrical and Control Engineering,North China University of Technology,Beijing 100144,China;China Electric Power Research Institute,Beijing 100192,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第7期2370-2379,共10页
High Voltage Engineering
基金
北京市高水平创新团队建设计划(IDHT20180502)。
关键词
微电网
时序多态不确定性
选择性数据驱动
可靠性评估
主导随机变量
密度方差
microgrid
sequential multi-state uncertainty
selective data-driven
reliability evaluation
dominant random variables
density variance
