供能设备模型对冷热电联供微网系统经济调度的影响

针对一种含光伏、蓄电池和冷热电联供的微网,在满足用户多种能源需求和联网运行的条件下,对系统中的微型燃气轮机、余热锅炉和制冷机等主要供能设备采用基于部分负荷(part load ratio,PLR)特性的模型,建立了以总运行成本最低为目标的微网日前动态经济调度的0-1混合整数非线性规划模型。通过求解某个楼宇CCHP型微网夏季典型日的算例,从优化调度方案、总运行费用等方面,比较了系统设备采用部分负荷特性模型和固定效率模型时的调度优化差异。结果表明,两种模型对于调度结果的误差不可忽略,部分负荷特性模型的结果更为准确;值得注意的是冷负荷所造成的模型误差比较显著。

含电动汽车的微网系统多目标经济调度

根据电动汽车的时空特性,建立了电动汽车无序充电和有序充放电的负荷模型。将电动汽车纳入微网,与其他分布式电源共同参与调度。构建了包含运行成本最低、二氧化碳排放最少、污染物处理费用最低的多目标微网系统经济调度模型。基于NSGA-II算法分析了多目标函数间的关系,最优解均匀地分布在Pareto最优解前沿上,保证了最优解的多样性。最后,将多目标函数处理为单目标函数,采用优先顺序法,基于不同的调度控制策略,对含电动汽车的微网系统进行经济调度。通过算例系统,验证了模型和策略的正确性。结果表明,电动汽车通过有序充放电模式入网比无序充电入网经济性更好,与此同时,负荷的波动越大,微网系统的运行总费用越高。

Dynamic Economic Dispatch for Microgrids Including Battery Energy Storage

Microgrids integrate distributed renewable energy resources, controllable loads and energy storage in a more economic and reliable fashion. Battery energy storage units are essential for microgrid operation, which make microgird become a strong coupling system in the time domain. Hence, the traditional methods of static dispatch are no longer suitable for microgrids. This paper proposes a dynamic economic dispatch method for microgrids. Considering microgrid as a discrete time system, the dynamic economic dispatch is to find the optimal control strategy for the system in finite time period. Based on this idea, the dynamic economic dispatch model for microgrids is established, and then the corresponding dynamic programming algorithm is designed. Finally, an example of microgrid is given, and the dynamic economic dispatch results are compared with that of the static dispatch. The comparison confirms the effectiveness of the proposed dynamic dispatch method.