考虑动态热定值的分布式光伏接纳能力评估方法

A Distributed PV Hosting Capacity Assessment Method Considering Dynamic Thermal Rating

  • 摘要: 配电网光伏接纳能力(PV hosting capacity, PVHC)受线路载流量约束,但传统上假设架空线路载流量是静态的,这使得配电网PVHC评估不准确,为此,提出了一种计及动态热定值(dynamic thermal rating, DTR)的配电网PVHC评估模型。首先通过引入电压灵敏度矩阵衡量光伏接入对配电网电压分布的影响,并结合遍历思想提出了一种分布式光伏选址方法。然后,考虑气象因素对架空线路载流量的影响,采用气象数据驱动的统计分析方法,建立了一种计及DTR的配电网PVHC评估模型。针对所建模型的非凸性,采用二阶锥松弛技术将其转化为易于求解的混合整数二阶锥规划问题。最后,基于实际数据在IEEE 33节点系统上对所提模型进行仿真,结果表明所提方法既可以有效提升配电网PVHC,又能避免在苛刻气象条件下由于DTR低于静态热定值带来的线路潮流大于线路实际载流量的过负荷风险,具有较好的应用和工程价值。

    Abstract: The PV hosting capacity(PVHC) of distribution networks is constrained by the line carrying capacity. However, the traditional assumption that the carrying capacity of overhead lines is static may lead to an inaccurate assessment of PVHC of distribution networks. In the light of this, a PVHC assessment model for distribution networks is proposed, taking into account the dynamic thermal rating(DTR). Firstly, a voltage sensitivity matrix is introduced to quantify the impact of PV access on the voltage distribution of distribution networks, and a distributed PV site-selecting method is proposed based on the traversal idea. Subsequently, in consideration of the influence of meteorological factors on the carrying capacity of overhead lines, a PVHC assessment model for distribution networks taking DTR into account is established through meteorological data-driven statistical analysis. Given the non-convexity of the constructed model, the second-order cone relaxation technique is adopted to transform it into an easy-to-solve mixed-integer second-order cone programming problem. Finally, the proposed model is simulated on the IEEE 33-bus system using actual data. The results indicate that the proposed method can effectively improve the PVHC of distribution networks. Additionally, it also avoids the overload risk of the line currents exceeding the actual line carrying capacity, which occurs as the DTR becomes lower than the STR under harsh meteorological conditions. In summary, the proposed method holds significant application and engineering value.

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