基于负荷重要性和源-荷互补性的离网系统终端电/热/冷负荷投切策略

针对如何减少离网系统供需不平衡以及提高能源利用效率的问题,该文提出一种基于负荷重要性和源-荷互补性的离网系统终端电/热/冷负荷投切策略。首先,定义负荷重要性指标以及源-荷互补性指标,并利用熵权法确定综合指标。然后,在此基础上提出基于单时间尺度供能和综合指标的负荷投切策略以及基于多时间尺度供能和综合指标的负荷投切策略。考虑到预测偏差会导致储能荷电状态(SOC)偏离计划值,进而影响负荷投切方案,该文利用基于模型预测控制(MPC)的滚动优化调度方法减少不确定性因素,实时跟踪储能SOC计划值。最后,以某离网系统夏季典型日为算例,验证了所提策略的有效性。

考虑负荷重要性与源-荷互补性的负荷恢复策略

针对综合能源系统非计划停电下如何减少负荷损失、提高能源利用效率的问题开展了研究,提出一种考虑负荷重要性与源–荷互补性的负荷恢复策略。首先,根据负荷特性构建负荷重要性评价指标,得出负荷的重要程度;然后,考虑源–荷互补特性,提出源–荷互补性评价指标;最后,利用熵权法综合考虑负荷重要性与源–荷互补性构建基于综合指标的负荷恢复策略模型。仿真结果表明,按照综合指标大小依次恢复负荷,能够最大限度减少负荷损失,有效提升综合能源系统孤网下有限能源的利用率,同时储能的配置容量也可大大降低,验证了所建负荷恢复策略模型的有效性。

考虑负荷重要程度含DG中压配电网电压调控策略

针对带有分布式发电(DG)的中压配电网,提出一种新型的电压调控策略,该策略考虑了负荷的重要程度。首先,构建对应的电压调控现状分析体系,识别现有策略面临的挑战;进一步介绍DG技术的基础知识。随后,建立负荷重要程度的评估模型,通过定量计算为调控机制提供依据。在此基础上,设计了基于负荷重要性的电压调控机制,并对中压配电网模型进行详尽的构建。研究的调控策略能有效提升电网运营效率,确保关键负荷的电压质量。最终通过定量分析验证该电压调控策略的有效性与优越性。

基于负荷频率特性的低频减载方案优化

针对当前低频减载整定方案大都没有计及负荷重要性,及负荷切除对于系统频率恢复的灵敏性的问题,本文建立了同时考虑上述两种负荷特性的低频减载优化新模型。该模型基于对系统负荷的分类、设置与每类负荷对应的低频减载方案。在保证全局统筹切负荷的情况下,以系统切负荷量最小和频率偏移最小作为优化目标,基于机电暂态仿真与粒子群算法相结合的方法,对低频减载方案中各类负荷的各轮次切负荷比例参数进行优化,从而获得最优的低频减载方案。实际算例证明了本文方法的有效性与正确性。

计及负荷差异的最小切负荷方法的研究

本文提出了应用多目标规划理论来研究电网规划中计及负荷重要性差异的最小切负荷量的计算问题。根据多目标规划理论,来建立电网规划中考虑负荷重要性的最小切负荷模型。该模型分析描述了可切负荷的重要性,最终转化为一确定性、多目标、线性规划问题并进行求解。该方法考虑了对发电机的优化调整,并在切负荷量最小的目标下考虑负荷重要性,尽可能的削减重要负荷。使用此方法对XXX系统进行仿真分析,验证了该方法的正确性和有效性。

Optimal fuzzy switch placement to increase automation level of electric distribution network considering asset management principles

Since distribution sector is inherent into high amount of failures, distribution companies (DISCOs) are responsible of attaining an acceptable value for the reliability indices and otherwise they will face up to complaints. So they are usually obligated by regulators to invest on reliability improvement of network. But this investment on reliability is usually from the DISCO’s viewpoint and is also irrespective of customer satisfaction level. In other words, customers are not at the same level of sensitivity to interruptions but DISCO improves the reliability of network without considering the differences in importance degree of loads and their level of reliability requirement. On the other hand DISCOs attempt to reduce their investment costs as much as possible. This paper introduces a novel approach in the field of joint switch placement that can reduce the switch cost from the perspective of asset management policies. To this end, two switch placement plannings in different types of strategies are performed to compare their results. Firstly as witch placement is performed based on reducing the total energy not supplied (ENS) of the system. Then by revising the strategy, a fuzzy switch placement is performed from the DISCO’s point of view which just considers the total ENS of load points most sensitive to interruptions known as important or critical loads. Furthermore, by meeting the related constraints, the reliability of low sensitive customers is disregarded. This is a load importance based planning which can result in switch cost reduction relative to the amount achieved in previous strategy and implies the management of risks associated with reliability and respective constraint. Fuzzy method and new switching mechanism in fuzzy environment of network are implemented to modeling and controlling the risks associated to ENS of critical loads and also the ENS of system.

计及储能控制策略的有源配电网可靠性评估

储能系统能够在配电网发生故障时对负荷供电,故障后采用的储能控制策略对负荷和系统的可靠性有很大影响。针对现有储能控制策略较为单一,应用时不够灵活,并且没有考虑负荷重要程度的问题,本文设计了考虑负荷重要程度的储能控制策略。首先,设计负荷重要程度评价指标体系,并建立基于改进序关系法的负荷重要性综合评估模型;然后,根据重要性评估结果,并结合储能系统的运行特性制定储能控制策略;最后,将储能控制策略嵌入到改进蒙特卡洛的有源配电网可靠性评估流程中,实现计及储能控制策略的有源配电网可靠性评估。以IEEE-RBTS仿真系统为例,说明了方法的有效性和实用性。