针对高渗透率分布式光伏接入低压配电网导致台区反向重过载、电压越限、三相不平衡等问题,提出了一种考虑高比例分布式资源接入的配电台区可开放容量多阶段评估方法.首先,分析了分布式光伏与负荷的逆调峰时序特性,考虑光伏超发引起台区反向重过载和电压越限约束以及三相不平衡对台区变压器负载能力的影响,提出了提升配电变压器负载能力的台区需求响应鲁棒优化模型.其次,考虑分布式光伏选相配置、电动汽车有序充电和柔性负荷需求响应,构建了高比例分布式光伏与电动汽车接入下配电台区最大可开放容量的选相配置-虚拟增容-校验修正多阶段协同评估模型.最后,基于嵌套列与约束生成算法(nested column and constraint generation algorithm,N-C&CG)将该模型转化为光伏选相配置优化、灵活性资源需求响应和上级变电站容量校验3个子问题进行交互式求解.通过典型配电台区仿真对比分析可知,所提方法能提升配电台区可开放容量9.84%以上,为配电网业扩报装配套接入方案优化和可靠运行提供了技术支撑.
Multi-Stage Assessment Method for Maximum Available Capacity of Low-Voltage Distribution Substations with High Proportion of Distributed Photovoltaic Integration
With the challenges posed by high penetration of distributed photovoltaic integration into low-voltage distribution networks,such as substation reverse overload,voltage violations,and three-phase imbalances,a multi-stage evaluation method for as-sessing the maximum available capacity of distribution substations considering high proportions of distributed resources is proposed.Firstly,the inverse peak load time-series characteristics of distributed PV and load are analyzed,considering constraints related to reverse overload and voltage violations caused by PV over-generation,as well as the impact of three-phase imbalance on the substa-tion transformer's load capacity.A robust optimization model for substation demand response to enhance distribution transformer load capacity is proposed.Secondly,considering phase selection configuration of distributed photovoltaics,coordinated charging of electric vehicles,as well as the demand response of flexible loads,a multi-stage collaborative evaluation model is proposed for determining the maximum available capacity of distribution substations under high proportions of distributed photovoltaic and electric vehicle integration.This model incorporates phase selection configuration optimization,virtual capacity expansion,and verification and correction stages.Finally,on the basis of nested column and constraint generation algorithm(N-C&CG),the model is transformed into three sub-problems:photovoltaic phase selection configuration optimization,demand response of flexible resources,and capacity verification at the upstream substation,which are solved interactively.Through comparative analysis based on simula-tions of typical distribution substations,the proposed method demonstrates a 9.84%improvement in the available capacity of the distribution substations,providing technical support for optimized connection schemes and reliable operation in the expansion of distribution networks.
low-voltage distribution networkdistributed photovoltaicavailable capacitysubstation overloadthree-phase imbalance
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