考虑时序相关性的需求侧资源可调节功率域聚合方法

在新能源高比例接入电网的背景下,需充分利用需求侧资源的灵活可调特性以保证电网的安全稳定与经济性。针对需求侧资源多样、数量多、容量小且分布广的特点,提出一种考虑时序相关性的需求侧资源可调节功率域聚合方法。首先,考虑需求侧资源功率调节的时序相关性,以相邻时段可调节功率域来量化其功率调节能力。其次,基于闵可夫斯基之和及上下边界近似法提出可调节功率域聚合方法,采用自适应分布鲁棒优化算法求解近似可行域边界辨识模型,确保其聚合最优性和解的可行性。然后,通过时段聚类方法得到适用于日前调度的多时段可调节功率域,降低计算复杂度。最后,通过算例对比分析可知,所提方法具有更高的计算效率和近似精度。

居民温控负荷聚合功率及响应潜力评估方法研究

温控负荷是参与电网功率平衡的一类有效资源,在电网紧急事故下有助于快速维持系统的频率稳定。但由于其分散分布特性造成调度中心难以直接获得其聚合功率及响应潜力。为引导温控负荷参与电网调控运行,建立了温控负荷的近似聚合模型,能够较为方便地确定其聚合功率的估计值及上下限范围。基于该模型,提出了一种计及响应不确定性的温控负荷聚合响应潜力评估方法,对温控负荷的聚合响应潜力及其分布特性进行了评估。通过仿真,验证了近似聚合模型和潜力评估方法的有效性。

计及灵活性聚合功率的源-荷分布式协调调度

为缓解大规模分布式能源接入主动配电网带来运行和备用的压力,有必要充分挖掘各灵活性资源以应对各种不确定性。文中提出一种计及灵活性聚合功率下的日前-日内两阶段分布式经济调度模型。首先,建立虚拟电池模型对主动配电网多种分布式灵活性资源集群聚合,基于闵可夫斯基和约束空间叠加法获取可调节聚合功率域,并以此为约束衔接日前-日内调度。其次,在日内实时滚动阶段提出计及灵活性聚合功率的输配电网分布式协调优化调度模型。更进一步,将一致性算法和调频控制结合,提出一种一致性调度控制策略对各个聚合等值集群进行灵活性聚合功率下经济调度模型的完全分布式求解。最后,算例验证了所提方法的有效性,调度部门在获取各分布式资源集群下主动配电网最优功率分配方案的同时,可以得到弹性备用功率区间和可调节功率域,帮助调度人员充分利用各种灵活性资源修正日前计划,有效应对各种不确定性因素。

基于等效功角同调的双馈风电场等值建模

首先以双馈风机数学模型为基础,推导了双馈风机电磁功率的表达式,分析了影响双馈风机电磁功率的相关因素,说明了以等效功角作为双馈风机同调识别观察量的合理性,即等效功角可表征不同工况及控制方式下双馈风机的动态特性,并定义了基于等效功角的双馈风机同调判断准则。其次,根据双馈风机的外特性,提出了功率聚合算法,即以双馈风机输出有功功率为权重求取等值机的等效内电势并确定等值母线及等值机参数;该方法有效解决聚类分群的复杂性和局限性,并提出了适合同调双馈机群母线化简方法。最后以实际南方电网中某地区风电场为例的仿真验证了所提模型具有合理性,聚合精度较高。

耦合聚类基线及舒适度的居民负荷需求响应评估方法

空调负荷虽然是参与需求响应的主力,但由于其所具有的高度分散特性导致需求响应能力很难被发现。建立了空调负荷的TCLs近似聚合功率模型;提出了基于温度设定值调整的TCLs负荷控制方法,结合用户舒适度的影响,分析调节特性,并通过考虑温度特征聚类的改进匹配日基线算法,对TCLs响应潜力进行评估。通过陕西某小区的实际数据来仿真不同温度调整量、不同典型日时间尺度下该小区的响应潜力,验证了所提模型和潜力评估方法的有效性。

促进分布式光伏消纳的配电网灵活资源可行域聚合方法

近年来,分布式光伏迎来爆发式增长,给低压配电网带来巨大承载压力,而分布式光伏就地消纳面临巨大挑战。随着新型电力系统建设的推进,配电网的分布式灵活资源呈现多样化和规模化特点,如何充分挖掘利用这些资源的灵活调节潜力,对促进光伏就地消纳至关重要。基于此,提出了基于改进顶点搜索的配电网灵活资源可行域聚合方法。首先,定义了技术经济可行域,建立多元灵活资源技术经济可行域聚合模型,表征资源聚合等值的技术经济特性,为优化调度提供功率和成本的可行信息,降低资源聚合复杂性。然后,提出分区分层、云边协同的配电网多元灵活资源聚合框架。该框架自下而上采用改进顶点搜索法实现海量资源的技术经济可行域等值聚合,再自上而下针对优化后的调度指令进行聚合功率分解,实现光伏就地消纳的最优运行。最后,通过算例分析验证技术经济可行域能够提供简洁直观的等值聚合信息,且所提灵活资源聚合方法能实现满足技术和经济约束的最优调控,可有效促进分布式光伏的就地消纳。

Evolution of two properties for scale-free network

Fitness of node can denote its competing power and clustering denotes the transitivity of network. Because the fitness of node is uncertain or fuzzy in some social networks, an explicit form of the degree distribution on fuzzy fitness is derived within a mean field approach. It is a weighted sum of different fuzzy fitness. It can be found that the fuzzy fitness of nodes may lead to multiscaling. Moreover, the clustering coefficient of node decays as power law and clustering coefficient of network behavior not-decrease-but-increase’ phenomenon after some time. Some computer simulation results of these models illustrate these analytical results.

基于相似度同调的双馈风电场聚合研究

文章提出了一种基于相似度同调的双馈风电场聚合方法。首先利用Prony算法提取各风电场中双馈风机故障下功率响应曲线的动态特征,基于相似理论确定双馈风机间振荡模式中相似部分,应用相似振荡模式中的频率、阻尼、幅值等信息定义了双馈风机同调判别的相似度量化指标并确定同调机群。然后,根据双馈风机的外特性,提出功率聚合算法,即以双馈风机输出有功功率为权重求取等值机的暂态内电势并确定等值母线及等值机参数。该方法从同调机群识别、同调母线聚合、同调机群参数聚合等方面,系统地解决了不同双馈风电场的同调聚合问题。参数聚合方法不仅解决了聚类分群的复杂性和局限性,而且有效保留原系统中电气与结构特征。最后以实际云南电网中某地区风电场为例进行仿真验证。

基于居民用户调控潜力精细评估的台区侧灵活资源多目标日前优化调度

以空调和电热水器为代表的居民温控负荷和电动汽车是台区用户侧重要的灵活可调资源,具有较大的调控潜力。由于居民负荷的参数不尽相同,配电调度中心难以直接准确评估其调控响应潜力,导致调度计划与实际调度要求存在较大差异。针对上述问题,构建了台区侧灵活资源协同调度框架,并建立各温控负荷和电动汽车聚合模型;提出了基于物理特征量分类聚合的灵活资源调控潜力精细评估方法;在此基础上,以电网削峰需求偏差最小和电网收益最大为目标,兼顾调峰目标和光伏出力的不确定性,建立了台区侧温控负荷和电动汽车灵活资源模糊机会约束多目标日前优化调度模型,并通过模糊约束条件清晰等价类转换实现模型求解。仿真结果表明该方法通过选择合适的权重系数可以实现电网调峰需求和经济利益的平衡,模糊机会约束规划置信水平取0.90时结果最优。

Influence of annealing temperature of ZnO film as the electron transport layer on the performance of polymer solar cells

The surface morphology of Zn O films at different annealing temperatures and the performance of polymer solar cells(PSCs) with Zn O as the electron transport layer are studied.The low temperature sol-gel processed Zn O film has smoother surface than that in higher temperature,which results in the best photovoltaic performance with a power conversion efficiency(PCE) of 3.66% for P3HT:PC61BM based solar cell.With increasing annealing temperature,the photovoltaic performance first deceases and then increases.It could be ascribed to the synergy effects of interface area,the conductivity and surface energy of Zn O film and series resistance of devices.

Optimization of the thermoelectric properties of poly(nickel-ethylenetetrathiolate) synthesized via potentiostatic deposition

The coordination polymer poly（nickel-ethylenetetrathiolate） （poly（Ni-ett））, formed by nickel（Ⅱ） and 1,1,2,2-ethenetetrathiolate （ett）, is the most promising N-type organic thermoelectric material ever reported; it is synthesized via potentiostatic deposition, and the effect of different applied potentials on the optimal performance of the polymers is investigated. The optimal thermoelectric property ofpoly（Ni-ett） synthesized at 0.6 V is remarkably greater than that of the polymers synthesized at 1 and 1.6 V, exhibiting a maximum power factor of up to 131.6μW/mK2 at 360 K. Furthermore, the structure-property correlation ofpoly（Ni-ett） is also extensively investigated. X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） analyses revealed that the larger size of crystalline domains and the higher oxidation state of poly（Ni-ett） synthesized at 0.6 V possibly results in the higher bulk mobility and carrier concentration in the polymer chains, respectively, accounting for the enhanced power factor.

Stereomeric effects of bisPC_(71)BM on polymer solar cell performance

Two stereomers of bisadduct analogues of [6, 6]-phenyl-C71-butyric acid methyl ester （bisPC71BM） were synthesized and their geometrical structures with cis- or trans-configuration were identified by X-ray crystallogra- phy. Although both of the bisPC71BM have similar spec- trometric and electrochemical properties, the spatial orientation of the two addition groups on C7o has impact on crystal packing and molecular assembly of bisPC71BM isomers and, in turn, photovoltaic performance in polymer solar cell based on poly（3-hexylthiophene） （P3HT） （with power conversion efficiency of 1.72 % and 1.84 % for the solar cells involving cis- and trans-bisPC71BM, respec- tively）. Although the power conversion efficiency remains to be improved, this work exemplifies that the photovoltaic properties of fullerene-based electron acceptors areinfluenced by aggregation of the stereomeric molecules and thus extends the guidelines for rational design of efficient fullerene acceptor.

Improved efficiency of ternary the blend polymer solar cells by doping a narrow band gap polymer material

A series of P3HT：PC71BM polymer solar cells （PSCs） with different PIDTDTQx doping concentrations were fabricated to in- vestigate the effect of the PIDTDTQx as a complementary electron donor on the performance of PSCs. The power conversion efficiency （PCE） of the optimized ternary blend PSCs （with 2 wt% PIDTDTQx） reached 3.87%, which is 28% higher than that of the PSCs based on P3HT：PCvlBM （control cells）. The short-circuit current density （J^c） was increased to 10.20 mA/cm2 compared with the control cells. The PCE improvement could be attributed to more photon harvest and charge carrier transport by appropriate doping PIDTDTQx. The energy transfer from P3HT to PIDTDTQx was demonstrated from the 650 nm emis- sion intensity decrease and the red-shifted emission peaks from 725 nm to 737 nm along with the increase of PIDTDTQx dop- ing concentrations.