Determination of Dynamic Load Condition of Aircraft Carrier based on Multivariable Distribution of Flight Parameters

In order to solve the design problem of dynamic load of a carrier-based aircraft,according to the relevant criteria of national military standards,eight key flight parameters of the dynamic load conditions for the aircraft carrier were selected.Based on the multivariable distribution data of landing flight parameters obtained from flight test,the distribution form and range limitation of each flight parameter were determined by using the probability distribution of each flight parameter and the spatial relationship among variables.Furthermore,100000 sets of data were constructed to simulate the landing condition of aircraft in the form of random number.After the envelope is screened by multivariable joint probability distribution,the boundary conditions were compared and merged,and finally the dynamic load conditions were obtained.In this paper,a set of dynamic load condition design method based on the aircraft requirements is constructed,which systematically covers all kinds of situations that occur in the process of aircraft landing,and improves the conventional design process of aircraft dynamic load.

Experimental Measurements of the Sensitivity of Fiber-optic Bragg Grating Sensors with a Soft Polymeric Coating under Mechanical Loading,Thermal and Magnetic under Cryogenic Conditions

The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.

Empirical Thermal Investigation of Oil-Immersed Distribution Transformer under Various Loading Conditions

The distribution transformer is the mainstay of the power system.Its internal temperature study is desirable for its safe operation in the power system.The purpose of the present study is to determine direct comprehensive thermal distribution in the distribution transformers for different loading conditions.To achieve this goal,the temperature distribution in the oil,core,and windings are studied at each loading.An experimental study is performed with a 10/0.38 kV,10 kVA oil–immersed transformer equipped with forty–two PT100 sensors(PTs)for temperature measurement installed inside during its manufacturing process.All possible locations for the hottest spot temperature(HST)are considered that made by finite element analysis(FEA)simulation and losses calculations.A resistive load is made to achieve 80%to 120%loading of the test transformer for this experiment.Working temperature is measured in each part of the transformer at all provided loading conditions.It is observed that temperature varies with loading throughout the transformer,and a detailed map of temperature is obtained in the whole test transformer.From these results,the HST stays in the critical section of the primary winding at all loading conditions.This work is helpful to understand the complete internal temperature layout and the location of the HST in distribution transformers.

基于傅里叶变换的多联机空调负荷提取及预测方法

多联机空调实际制冷量通常不等同于房间真实的空调负荷需求,导致基于数据驱动的负荷预测模型的预测效果往往较差。本文提出了一种基于傅里叶变换的从实际制冷量数据中提取空调真实负荷数据的方法。案例预测结果表明,该方法能够有效提取空调负荷数据,并能将基于人工神经网络的超短期空调负荷预测模型精度提升10.94%。

面向脉冲负载的基于超级电容储能UPQC设计及控制策略研究

针对带有脉冲负载电网的电压畸变和电流畸变问题,设计了带有超级电容储能的三电平统一电能质量调节器,提出了基于人工神经网络的方法对串联和并联补偿单元进行控制,基于双闭环PI控制的方法对超级电容储能单元进行控制。其中,串联补偿单元进行电压补偿,以维持负载电压的稳定,保证负载的用电需求;并联补偿单元进行电流补偿,以维持电源电流的稳定,避免电网受到持续大幅冲击;超级电容储能单元对直流侧进行充放电,以维持直流侧电压的恒定,保证串、并联侧的正常工作。所提方法省去了繁琐的坐标变换过程,避免了多个滤波器造成相位滞后的问题。仿真实验结果表明,所提拓扑和控制策略有助于改善带有脉冲负载电网的电能质量。

水蓄冷空调系统运行策略的分析

我国空调系统用电量占比越来越大,空调节能降耗成为建筑节能的重要研究方向。水蓄冷技术是空调节能的重要技术之一。介绍水蓄冷空调系统的特点和工作原理,提出基于复杂工况的建筑负荷预测和控制方法,实现蓄冷设备对能源的灵活消耗和存储。根据建筑空调在不同蓄冷率下的环控策略分析可知,通过合理优化运行策略,水蓄冷空调系统具有良好的投资经济性。

关于消防员电梯的几点思考

结合相关规范条文,针对电气设计人员对于消防员电梯井道照明、机房空调配电及五方通话等方面存在的疑惑或争议进行探讨,并提出笔者的见解。

Optimal Scheduling of Air Conditioners for Energy Efficiency

Energy saving is one of the most important research hotspots, by which operational expenditure and CO2 emission can be reduced. Optimal cooling capacity scheduling in addition to temperature control can improve energy efficiency. The main contribution of this work is modeling the telecommunication building for the fabric cooling load to schedule the operation of air conditioners. The time series data of the fabric cooling load of the building envelope is taken by simulation by using Energy Plus, Building Control Virtual Test Bed （BCVTB）, and Matlab. This pre-computed data and other internal thermal loads are used for scheduling in air conditioners. Energy savings obtained for the whole year are about 4% to 6% by simulation and the field study, respectively.

考虑用电满意度和经济性的空调负荷集群建模及控制策略

空调负荷已成为电力系统重要的需求响应资源,由于其数量多、状态差异性大,造成电力公司难以直接获取其聚合功率并开展调控,文中提出考虑空调负荷集群用电满意度和经济性的控制策略。借助负荷聚合商代理机构,根据热参数模型得到单台空调的可调控容量,建立了人体热舒适度下的建筑物热参数模型进行空调群分类,考虑初始状态不确定性所导致的可关断时间大小差异性分组方法。构造用电满意度函数,对空调群中的各组负荷进行满意度优先级排序,聚合商根据各类空调群的可调控潜力和满意度优先级大小顺序,对各聚类空调群实施优先级划分的分组轮停控制策略,优化空调群的小组占空比,完成负荷削减计划,使自身经济收益最优,最后通过算例验证了该调控策略的合理性和有效性。

考虑用户行为的变频空调参与一次调频控制策略

随着电力系统的发展,电网频率稳定运行迎来巨大挑战,发电侧调频成本也日益激增。为应对电网面临的诸多不利影响,使负荷侧参与电网调频,提出基于改进下垂控制的变频空调参与一次调频的分层控制策略。根据变频空调的工作特性,建立基于一阶物理模型的负荷聚合商模型;考虑空调温度状态(SOA),对普通下垂控制模型进行改进,并且考虑用户舒适度,建立基于SOA优先级列表的变频空调有序参与响应控制策略。所提策略能高效调度变频空调,调节系统频率。

大规模空调负荷参与新能源电力系统调频的无模型自适应控制方法

针对大规模空调负荷参与新能源电力系统的调频问题,提出了一种基于无模型自适应控制的频率调节方法。首先,建立了包含大规模风力发电的多区域互联电网模型,风力发电系统通过虚拟惯量控制参与电网调频;其次,采用等效热力学参数模型构建了定频和变频空调模型,通过大规模空调聚合建立了空调负荷调频模型;然后,利用无模型自适应控制算法完全数据驱动、无需模型参数、抗干扰能力强、适用于非线性时变系统的特点,设计了区域互联电网自动发电控制器以及空调控制器,实现了大规模空调负荷参与新能源电力系统的频率控制。算例仿真在三区域互联电力系统展开,在负荷扰动、风电波动和环境温度变化等条件下进行的仿真表明:提出的无模型自适应频率控制算法能够控制大规模空调负荷有效抑制风电接入和负荷扰动带来的频率波动。

UAV-mounted Ground Penetrating Radar: an example for the stability analysis of a mountain rock debris slope

This paper describes scientific research conducted to highlight the potential of an integrated GPR-UAV system in engineering-geological applications.The analysis focused on the stability of a natural scree slope in the Germanasca Valley,in the western Italian Alps.As a consequence of its steep shape and the related geological hazard,the study used different remote sensed methodologies such as UAV photogrammetry and geophysics survey by a GPR-drone integrated system.Furthermore,conventional in-situ surveys led to the collection of geological and geomorphological data.The use of the UAV-mounted GPR allowed us to investigate the bedrock depth under the detrital slope deposit,using a non-invasive technique able to conduct surveys on inaccessible areas prone to hazardous conditions for operators.The collected evidence and the results of the analysis highlighted the stability of the slope with Factors of Safety,verified in static conditions(i.e.,natural static condition and static condition with snow cover),slightly above the stability limit value of 1.On the contrary,the dynamic loading conditions(i.e.,seismic action applied)showed a Factor of Safety below the stability limit value.The UAV-mounted GPR represented an essential contribution to the surveys allowing the definition of the interface debris deposit-bedrock,which are useful to design the slope model and to evaluate the scree slope stability in different conditions.

商业建筑空调系统参与城市电网负荷调控综述

实现“碳达峰、碳中和”目标的关键在于城市电网的经济和高效运行。然而,波动性新能源的增加以及负荷峰谷差的扩大等因素为城市电网带来了挑战。传统发电机组通过频繁调节出力来维持系统的稳定运行,这种方式能效较低,而且还面临可调节资源不足的问题。作为城市电网总耗电量的重要组成部分,商业建筑空调系统有潜力作为调节资源参与电网调控。同时,借助建筑的热储能特性,可以在满足用户室内温度舒适需求的同时进行调控,其潜力巨大。为了更好地发掘商业建筑空调系统的调控能力,展示了典型商业建筑空调系统的单体模型和聚合模型,并概述了商业建筑空调系统的调控潜力评估方法和控制技术。同时还对比分析了国内外的典型商业建筑空调系统示范工程,并针对当前的发展状况提出了一些建议和展望。

新型站用统一电能质量调节器及控制策略

提出了一种改善变电站电能质量装置站用统一电能质量调节器(UPQC)结构及其控制策略,所提UPQC可接入三相三线或三相四线系统中并实现串并联电能质量调节。给出了UPQC内部串联及并联有源电力滤波器(APF)直接补偿控制策略,其中串联APF控制为基波正弦电流源,并联APF控制为基波正弦电压源。所提控制策略无需检测电压和电流补偿量,有效降低了系统控制复杂度。最后通过系统仿真及样机实验验证分析了所提站用UPQC及控制策略对不平衡负载、非线性负载等工况下的电能质量提升的有效性。

基于需求侧响应的水蓄冷空调经济性分析

随着空调的普及和推广,针对夏季空调负荷的需求侧响应和管理日益引起人们的重视,水蓄冷空调技术作为一种高效清洁循环利用的供冷技术,具备优良的经济效益和社会效益。在总结水蓄冷空调系统经济性研究的基础上,对水蓄冷空调系统和单纯空调制冷系统的经济性进行量化建模,并选择河北某办公区域项目的水蓄冷空调系统进行了实证分析测算,结果表明,水蓄冷空调系统具备良好的经济效益和社会效益。

基于粗糙集和PSO-Elman的商业建筑空调冷负荷预测

为了精确预测商业建筑空调的冷负荷,建立基于粗糙集和PSO-Elman神经网络的预测模型。首先利用粗糙集对空调冷负荷的影响因子进行属性约简,然后应用粒子群算法优化Elman神经网络的权值和阈值,建立PSO-Elman商业建筑空调冷负荷的预测模型。采集桂林某商业建筑的空调数据和气象参数验证PSO-Elman预测模型的预测性能,并将该模型的预测结果与Elman预测模型的预测结果进行对比分析。研究结果表明,PSO-Elman预测模型的预测精度高于Elman预测模型,PSO-Elman预测模型预测结果的平均绝对相对误差、均方根相对误差、均方根误差和平均绝对误差分别为4.87%,6.15%,423.71和335.86,与Elman预测模型的预测结果相比,这些误差参数分别降低了2.46%,2.46%,169.65和156.57。由此可知,PSO-Elman预测模型能够精确有效地预测商业建筑空调的冷负荷。

基于柔性负荷和建筑多能源系统的电网峰谷调节算法

针对建筑能源系统负荷多样,导致电网波动和负荷峰谷差日益增大的问题,提出了一种基于柔性负荷与建筑多能源系统的电网峰谷调剂算法,以实现多能源系统联合参与的电网峰谷调节.该算法通过构建储能设备和空调系统的功率模型,来建立多能源系统负荷与功率优化的电网峰谷调节目标函数.同时,针对电网峰谷调节的特点提出了一种改进的粒子群优化算法,以求解该目标函数实现电网的峰谷调节.仿真分析与实验结果表明,所提出的方法优于单纯使用储能设备和空调系统的电网峰谷调节方法,能够显著提高负荷的平滑度与能源利用率.

考虑多主体的可调节负荷聚合参与市场平衡策略研究

随着我国新能源发电占比不断提高,仅靠传统手段已难以维持电网安全平稳运转和动态平衡,亟需通过调整灵活负荷资源积极参与电网调节。本文以电动汽车、空调、储能等柔性负荷作为参与电网平衡的主体,研究通过负荷聚合的形式参与多级电网平衡。首先,建立各个参与平衡主体的优化模型;其次,基于电价型需求响应与主从博弈,提出以配电网运营商经济效益最大、电动汽车与空调各自用电成本最低为目标的优化模型。最后,建立上层为配电网运营商,下层为电动汽车聚合商和空调聚合商的主从博弈模型。算例分析表明,所提出的优化模型在提高各主体经济性的同时能有效降低峰谷差。

生产工艺对空调冷凝器集液管管夹性能和成本的影响

通过对北美一款商用空调的冷凝器集液管管夹的设计升级,研究了注塑和挤压的加工工艺对塑料零件性能和成本的影响;通过材料理化性能数据表,对原材料进行了对比论证,确保两种加工工艺使用的材料具有高度相似的物理和化学性能。通过FEA计算工具、负载力测试和螺钉孔破坏转矩测试实验来对两种工艺生产出的产品的可靠性进行对比论证,最终将产品零件的加工工艺由挤压更改成更为适合的注塑工艺,从而提升产品的性能和外观,并使成本得到了一定的降低。