基于时序方向矩阵的主动配电网运行灵活性评估

Operational Flexibility Evaluation of Active Distribution Network Based on the Sequential Direction Matrix

针对现有配电网灵活性评估未能考虑配电网对不确定变量预测误差适应程度的问题,提出了一种基于时序方向矩阵的主动配电网灵活性评估方法.首先,为突破方向矩阵仅适用于单一时间断面灵活性评估的局限性,将方向矩阵扩展为时序方向矩阵,据此建立基于时序方向矩阵的不确定变量模型.其次,建立主问题与子问题迭代的数学模型与求解框架,其中子问题基于不确定变量模型进行可行性判断并求解特定方向上可行域边界,主问题在不确定域中寻找临界方向,并将该方向的可行域边界作为灵活性充裕与否的判据.再次,提出了社会学习粒子群优化与二分法相结合的求解算法.最后,在算例分析中对比了本文方法与遍历法,两种方法所得到的结果在精确到小数点后4位时基本一致,说明了本文模型与方法的正确性;通过分析多种不确定变量条件下配电网的灵活性验证了本文方法的适应性;配电网时序灵活性评估结果表明通过时序方向矩阵中元素数值可以判断灵活性缺失的主要时段及诱因,本文方法可有效反映配电网资源配置增加对灵活性的量化提升作用.

As the adaptation of uncertain variables is not considered in existing works,a novel flexibility analysis method for active distribution networks based on a sequential direction matrix is presented in this study.First,to address the limitation that the direction matrix is only suitable for the flexibility evaluation of a single time period,the direction matrix is extended to the sequential direction matrix.On this basis,the uncertain variable model based on the sequential direction matrix is established.Second,the mathematical model and solution framework of the main problem and subproblem are established for the sequential flexibility evaluation of the active distribution network.The subproblem is used to assess the feasibility on the basis of the uncertain variable model,and the goal is to solve the boundary of the feasible region in a specific direction.The main problem is used to determine the direction that adapts the worst to the prediction error out of all directions of the uncertain region,that is,the critical direction.Third,an algorithm combining the social learning particle swarm optimization with the bisection algorithm is proposed.Finally,the proposed method and the traversing method are compared in the case study.The results of the two methods are the same when they are accurate up to four decimal places;thus,the correctness of the proposed method is illustrated.The adaptability of the method is verified by analyzing the flexibility of the distribution network under different uncertain variables.The result of the sequential flexibility evaluation of the distribution network shows that the main time period and the cause of the lack of flexibility can be assessed using by the element value in the sequential direction matrix.The method presented in this study can effectively reflect the quantitative improvement of the flexibility caused by the increase in resources in the distribution network.