一种计及主变可载性约束的三阶段配电网供电能力实时评估方法

A Three Stage Real-Time Evaluation Method for Power Supply Capability of Distribution Network With Constraint of Transformer Overload Capacity

针对现有配电网供电能力评估方法未能考虑主变可载能力的问题,建立了主变可载性约束模型,该模型考虑变压器的绕组热点温度约束、故障率约束及经济损益约束,通过定级风险严重度等级对变压器增容系数进行风险约束校验。此外,针对现有评估方法难以适应复杂多变实际场景的问题,提出了不同工况下的评估原则。基于以上2点,文章提出一种计及主变可载性约束的配电网供电能力评估方法,方法包含预评估、约束分析、校验评估3个阶段,以重复潮流法为基础进行循环评估得到最终结果。仿真结果表明该方法可计及主变的可载能力,且主变增容运行时配电网最大供电能力呈现出明显的时间特性,急救负载条件下的最大供电能力提升百分数大于周期性负载条件下的情况。该方法可为不同场景下的配电网调度运行提供辅助决策建议。

To solve the problem that existing methods for power supply capability evaluation of distribution network do not consider transformer overload capacity, a transformer overload constraint model is proposed. The model considers constraints of winding hot-spot temperature, failure rate and economy, and inspects capacity-increasing coefficient via rating risk severity level. Besides, existing methods can＇t adapt to complex scenes, so this paper proposes different evaluation principles. Based on above two points, a new evaluation method with transformer overload capacity is proposed. The method includes three stages： pre-evaluation, constraint analysis and verification evaluation, and final results are obtained with repeated power flow method. Simulation results show that the method takes transformer overload capacity into account. Maximum power supply capability has obvious time-dependent feature under overload condition and its percentage increase of shot-time emergency loading is bigger than that of normal cyclic loading. The method can provide an assistant decision-making basis for different scenes.