Solving the absent assignment problem of the shortest time limit in a weighted bipartite graph with the minimal weighted k-matching algorithm is unsuitable for situations in which large numbers of problems need to be ...Solving the absent assignment problem of the shortest time limit in a weighted bipartite graph with the minimal weighted k-matching algorithm is unsuitable for situations in which large numbers of problems need to be addressed by large numbers of parties. This paper simplifies the algorithm of searching for the even alternating path that contains a maximal element using the minimal weighted k-matching theorem and intercept graph. A program for solving the maximal efficiency assignment problem was compiled. As a case study, the program was used to solve the assignment problem of water piping repair in the case of a large number of companies and broken pipes, and the validity of the program was verified.展开更多
随着电力系统中可再生能源比重逐渐增加,电力系统频率波动的风险增大。飞轮和锂电池可以优势互补,作为混合储能应用于电网一次调频中,有效解决系统频率波动问题。为了充分发挥飞轮和锂电池各自的调频优势,提出基于自适应荷电状态(state ...随着电力系统中可再生能源比重逐渐增加,电力系统频率波动的风险增大。飞轮和锂电池可以优势互补,作为混合储能应用于电网一次调频中,有效解决系统频率波动问题。为了充分发挥飞轮和锂电池各自的调频优势,提出基于自适应荷电状态(state of charge,SOC)的电池-飞轮混合储能一次调频控制策略。首先,建立含正、负虚拟惯性控制和虚拟下垂控制的权重分配一次调频模型;然后,利用飞轮和锂电池SOC对一次调频模型参数进行修正,提高混合储能在SOC阈值附近的一次调频能力;最后,仿真对比各调频场景下文中控制策略与其他控制策略的调频能力及SOC恢复效果。研究结果表明,文中控制策略下储能系统SOC波动范围最小,电池不会发生过充过放,且系统频率波动不超过±0.2 Hz,可以提高电网频率稳定性。展开更多
文摘Solving the absent assignment problem of the shortest time limit in a weighted bipartite graph with the minimal weighted k-matching algorithm is unsuitable for situations in which large numbers of problems need to be addressed by large numbers of parties. This paper simplifies the algorithm of searching for the even alternating path that contains a maximal element using the minimal weighted k-matching theorem and intercept graph. A program for solving the maximal efficiency assignment problem was compiled. As a case study, the program was used to solve the assignment problem of water piping repair in the case of a large number of companies and broken pipes, and the validity of the program was verified.
文摘随着电力系统中可再生能源比重逐渐增加,电力系统频率波动的风险增大。飞轮和锂电池可以优势互补,作为混合储能应用于电网一次调频中,有效解决系统频率波动问题。为了充分发挥飞轮和锂电池各自的调频优势,提出基于自适应荷电状态(state of charge,SOC)的电池-飞轮混合储能一次调频控制策略。首先,建立含正、负虚拟惯性控制和虚拟下垂控制的权重分配一次调频模型;然后,利用飞轮和锂电池SOC对一次调频模型参数进行修正,提高混合储能在SOC阈值附近的一次调频能力;最后,仿真对比各调频场景下文中控制策略与其他控制策略的调频能力及SOC恢复效果。研究结果表明,文中控制策略下储能系统SOC波动范围最小,电池不会发生过充过放,且系统频率波动不超过±0.2 Hz,可以提高电网频率稳定性。
文摘货位分配(storage location assignment problem,SLAP),即在存储区域为物料分配货位的过程。当仓库布局、拣货路径、订单组合等其他因素确定时,货位分配策略对订单拣货效率有很大影响。本文研究实际生产型仓库中的关联物料区位分配问题。生产中使用的相对稳定的BOM(bill of material)使得仓库中的物料具有稳定的相关性,因此,本文考虑将具有需求关联的物料存储在同一区域,以尽可能地减少在拣选物料时所需要的区域访问次数。此外,该仓库还存在两个重要特征,即存在两类不同尺寸货架构成的两类不同容量的区域及采用严格的重物下置原则。本文建立了以最小化区域访问次数为目标的数学规划模型,给出了求解该问题的一种聚类启发式方法与自适应大邻域搜索算法(adaptive large neighborhood search,ALNS),并设计了能够反映物料关联特征的小规模和大规模算例用于测试两种算法的性能。将两个算法结果与随机策略、CPLEX求解结果对比,结果显示聚类启发式方法与ALNS在大规模算例中表现明显优于随机策略和CPLEX的求解结果。
