分布式电源出力与负荷相关性对配电网可靠性的影响分析

Impact of distributed generation output and load correlation on distribution network reliability

分布式电源输出功率受一次能源制约,不仅呈现较强的波动性,还具有一定的相关性;负荷间及其与电源间也同样存在相关性问题。为研究能量波动性与相关性对供电可靠性的影响,在传统配电网可靠性解析法的基础上,分析负荷转供概率及其影响因素。结合分布式电源输出和负荷功率的概率分布及相关系数矩阵,基于Nataf变换技术生成相关随机变量的样本空间,提出计及分布式电源出力和负荷相关性的配电网可靠性评估方法。该方法具有概念清晰、实现简单等优点,能有效解决含分布式电源配电网可靠性建模时由于分布式电源之间出力服从相关非正态分布而难以处理的困难。采用改进的IEEE-RBTS BUS6系统验证了所提模型及方法的可行性。

Restricted by the primary energy,the power output of DG （Distributed Generation） presents obvious fluctuation and certain correlation. Furthermore ,the correlation exists also among loads and between load and power source. For researching the impact of energy fluctuation and correlation on power supply reliability,the load transfer probability and its influencing factors are analyzed based on the traditional analytic approach of distribution network reliability. Combined with the probability distributions and corresponding correlation matrix of DG output and load power,the Nataf transformation technology is applied to generate the sample space of related random variable and a method of distribution network reliability assessment is proposed,which,with the advantages of clear concept and simple implementation,can effectively deal with the related non-normal distribution among DG power outputs during the reliability modelling of distribution network containing DGs. The improved IEEE-RBTS BUS6 system is adopted to verify the feasibility of the proposed model and method.