考虑负荷弹性空间的配电网可靠性扩展规划方法

A Reliability-constrained Distribution Network Expansion Planning Method Considering Flexibility Space of Power Demand

现有配电网可靠性扩展规划通常通过新建变压器、线路等设备提升供电可靠性水平,忽略了负荷弹性调整对可靠性的影响。电力用户可通过投建储能设备,实现负荷需求弹性化,提升供电可靠性水平,减少配电网变压器、线路等昂贵设备投资。文中提出基于多参数规划理论的负荷弹性空间刻画方法。所提方法考虑用户储能设备投资决策,以配电网所需供给负荷为耦合变量,研究满足用户用电需求的负荷弹性空间,并将用户投资决策成本表示为负荷弹性空间上的分段解析映射函数,反映用户投资决策对可靠性的影响。进一步,为缓解多时段高维负荷弹性空间的计算量爆炸问题,提出基于负荷波动特征解耦策略的负荷弹性空间快速刻画方法。最后,基于凸松弛技术和big-M法,提出考虑负荷弹性空间的配电网可靠性扩展规划线性模型,提升供电可靠性水平。基于24节点配电网测试系统,验证所提方法的有效性和准确性。

The expansion planning of existing distribution network reliability majorly improves reliability by investing new devices(e.g., transformers, lines). However, the flexibility of power demand is usually ignored. In fact, by investing on storage devices by demand users, the flexibility of power demand can be utilized to reduce the expensive investment costs in distribution networks. This paper presented a calculation method of flexibility of power demand based on the multi-parametric programming theory. Considering investment decisions of storage by users, this paper treated power demand supplied by distribution networks as coupling variables and explicitly formulated the investment costs as an affine mapping function over the flexible operation space. Furthermore, to alleviate the heavy computational burden caused by multi-period high-dimension flexibility space of power demand, this paper presented a fast calculation method based on the decomposition strategy from demand characteristics.Finally, based on the convex relaxation and Big-M technologies, this paper presented a linear programming model for the distribution network expansion planning considering flexibility of demand, improving reliability in distribution networks. The validation and effectiveness of the presented methods were demonstrated based on a 24-bus distribution network.