Analysis for Effects of Temperature Rise of PV Modules upon Driving Distance of Vehicle Integrated Photovoltaic Electric Vehicles

The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO2 emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.

Scheme of long distance power supply for electrified railway traction network based on traction cable

Purpose–The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network.This paper aims to study the scheme composition and power supply distance(PSD)of the scheme.Design/methodology/approach–Based on the structure of parallel traction network(referred to as“cable traction network(CTN)”),the power supply modes(PSMs)are divided into cableþdirect PSM and cableþautotransformer(AT)PSM(including Japanese mode,French mode and new mode).Taking cableþJapanese AT PSM as an example,the scheme of long distance power supply for CTN under the PSMs of co-phase and out-of-phase power supply are designed.On the basis of establishing the equivalent circuit model and the chain circuit model of CTN,taking the train working voltage as the constraint condition,and based on the power flow calculation of multiple train loads,the calculation formula and process for determining the PSD of CTN are given.The impedance and PSD of CTN under the cableþAT PSM are simulated and analyzed,and a certain line is taken as an example to compare the scheme design.Findings–Results show that the equivalent impedance of CTN under the cableþAT PSM is smaller,and the PSD is about 2.5 times of that under the AT PSM,which can effectively increase the PSD and the flexibility of external power supply location.Originality/value–The research content can effectively improve the PSD of traction power supply system and has important reference value for the engineering application of the scheme.

Time-Domain Protection for Transmission Lines Connected to Wind Power Plant based on Model Matching and Hausdorff Distance

The system impedance instability,high-order harmonics,and frequency offset are main fault characteristics of wind power system.Moreover,the measurement angle of faulty phase is affected by rotation speed frequency component,which causes traditional directional protections based on angle comparison between voltage and current to operate incorrectly.In this paper,a time-domain protection for connected to wind power plant based on model matching is proposed,which compares the calculated current and the measured current to identify internal faults and external faults.Under external faults,the calculated current and measured current waveform are quite similar because the protected transmission lines is equivalent to a lumped parameter model and the model itself is not damaged.However,the similarity of calculated current and measured current is quite low,due to destroyed integrity of model under internal faults.Additionally,Hausdorff distance is introduced to obtain the similarity of the calculated current and measured current.Since the proposed protection scheme is applied in time domain,it is independent from current frequency offsets of wind energy system,high-order harmonics,and system impedance variations.Comprehensive case studies are undertaken through Power Systems Computer Aided Design(PSCAD),while simulation results verify the accuracy and efficiency of the proposed approach in fault identification.

On the differences Between Body Language in China and America From the perspective of Power Distance

Over the past decades,quite a lot of scholars both in and out of China have dedicated themselves to the research of body language and a great number of works have been published to give impetus to the study of body language.The paper aims to study the differences of body language in China and America from the perspective of power distance to help people from different cultural backgrounds achieve a successful intercultural communication and avoid conflict as much as possible.

A New Adaptive Technique for Enhancement of Zone-2 Settings of Distance Relay

This paper presents a technique that increases the second-zone coverage of distance relays without causing overreach problems. The technique is based on the impedance seen by distance relays when faults are simulated on the reach of zone-1 relays. The approach checks the relay operation for the maximum as well as the minimum generation outputs of the power system. The proposed technique can be used for different reach setting for zone-1. Results show that it is possible to increase the coverage provided by zone-2 distance relays without causing coordination problems with the primary relays that protect the lines emanating from the remote bus. The proposed method is modified for use in an adaptive protection system. It is shown that further improvements can be achieved when settings are calculated using the proposed method and the prevailing system conditions. The proposed method and its adaptive version were applied to a part of the Power system. The simulation of the system is done by using PSCAD-EMTDC software. The simulated results are observed and compared with the conventional and proposed technique.

A Smart Strategy for Blocking the Distance Protection Function during VT Fuse Failure

Saving the electrical power system in stable condition is considered as one of important challenges to avoid any failure of high voltage equipment. Additionally, with the increasing off the critical loads, it’s very important to use the accurate protection system that can deal with any abnormal condition. This paper studies one of critical cases that can effect on the coordination of the protection system with the faults during fuse fail condition. Over Head transmission line (OHTL) is the most part in the power system that faces the disturbances, which can be protected by multi-protection functions as line differential function, distance protection function, over current, earth fault, over/under voltage etc. The distance protection function is depending on the line voltage and the load current to calculate the load zone. This paper aims to prevent the falls operation of distance protection function during voltage transformer fuse failure condition.

考虑移动氢能存储的港口多能微网两阶段分布鲁棒优化调度

为有效应对海上风电固有的间歇及波动性给港口多能微网带来的不确定性风险,提出一种考虑移动氢能存储的港口多能微网两阶段分布鲁棒优化调度模型。首先,结合Wasserstein距离实现风电出力概率分布模糊集的精确刻画,并通过非参数核密度估计拟合海上风电预测误差概率分布,获得不同置信水平下风电出力区间及场景。其次,分析氢能船舶、汽车等移动氢能存储资源对间歇性风电出力的能源存储潜力,并结合用能心理、交通属性差异,将两者分别建模为激励型、价格型需求响应,实现港口移动氢能存储灵活性资源的高效聚合。再次,针对含移动氢能存储的港口多能微网,构建基于概率分布模糊集的日前-日内两阶段分布鲁棒优化调度模型,并运用线性决策规则与强对偶理论将其转换为混合整数线性规划模型求解。最后,基于海上风电实测数据进行仿真验证。结果证明,移动氢能存储可显著提升港口多能微网的低碳灵活性,所提模型在兼顾港口多能微网经济性的同时,可进一步保证风电不确定性风险下的鲁棒性。

基于KL散度距离处理风电不确定性的负荷恢复分布鲁棒优化

在构建以新能源为主体的新型电力系统的背景下,在恢复控制过程中积极利用新能源并充分应对其对运行安全带来的潜在风险对于减小停电损失具有重要意义。首先,为了表征风电出力的不确定性,采用KL散度(Kullback-Leibler)距离作为筛选极端风电出力场景的控制条件,并据此构建模糊集作为风电出力典型场景。在满足相关运行安全约束的前提下,建立了以最大化加权负荷恢复量为优化目标的分布鲁棒优化模型以制定计及风电的负荷恢复方案。经松弛处理和对偶转换所得到的混合整数二阶锥模型可调用商业求解器求解。以接入规模风电场的IEEE 10机39母线系统为例进行仿真,结果表明:相比于传统的鲁棒优化方法,该方法降低了优化结果的保守性,有助于加快负荷恢复,减小停电损失。

领导员工互动公平对团队创造力的影响机制:一个被调节的中介模型

领导员工互动公平作为一种组织公平,反映团队成员对自身与领导沟通质量的感知,能够有效增强团队创造力,维持企业核心竞争优势,促进企业繁荣稳定发展。基于102个知识型团队样本,以团队内竞争为中介变量,以权力距离导向为调节变量,从直接和间接传导机制两个维度阐释领导员工互动公平对团队创造力的内在影响机理,研究发现:①领导员工互动公平与团队创造力正相关;②团队内发展性竞争在领导员工互动公平与团队创造力关系中发挥完全中介作用;③权力距离导向正向调节领导员工互动公平与团队发展性竞争的关系、负向调节领导员工互动公平与团队过度性竞争的关系;④权力距离导向正向调节团队内发展性竞争在领导员工互动公平与团队创造力关系间的中介作用。

企业领导权变奖励影响员工职业承诺机理探讨

企业领导权变奖励影响员工职业承诺有赖于由员工心理契约违背中介完成并受制于员工权力距离的调节。笔者基于组织公平理论,构建了企业领导权变奖励影响员工职业承诺机制的一个有调节的中介模型,在此基础上以590份来自对中国内地企业普通员工问卷调查的有效数据,运用层级回归和bootstrap方法实证检验了企业领导权变奖励与员工职业承诺之间的关联。检验结果证实:企业领导权变奖励显著正向影响员工职业承诺;员工心理契约违背部分中介作用于企业领导权变奖励对员工职业承诺的影响;员工权力距离既与企业领导权变奖励影响员工职业承诺的关系负相关,也反向调节此间员工心理契约违背的中介作用。本研究通过尝试性地将员工心理契约违背和员工权力距离等相关变量引入对企业领导权变奖励影响员工职业承诺关系模型的实证检验,揭示了企业领导权变奖励对员工职业承诺的相关影响机理,从领导奖励层次与员工职业承诺的关联上扩展了组织公平理论的应用边界,丰富了有关公司内部治理方面的现有文献,研究结论有助于为企业经营管理中制定科学合理的奖惩条例和处理好企业领导与员工的干群关系提供理论依据。

测距仪信号功率谱及邻道泄露功率

为了解决宽带航空数据链频率资源匮乏的问题,L频段数字航空通信系统(L-DACS,L-band digital aeronautical communications system)将以内嵌的方式部署在航空无线电导航L频段测距仪(DME,distance measure equipment)波道间,因此,不可避免产生测距仪信号干扰L-DACS系统接收机的问题。为了定量描述DME/N(distance measure equipment/normal)与DME/P(distance measure equipment/precision)信号带外泄露对LDACS系统接收机的影响,首先建立了DME/N与DME/P信号数学模型,然后理论推导出DME/N与DME/P信号的功率谱密度表达式,以此为基础研究了DME/N与DME/P信号带外泄露对邻道部署的L-DACS系统接收机的影响,最后通过计算机仿真验证了理论分析结果的正确性。研究表明:DME信号带外泄露对L-DACS系统的影响主要表现在第一邻道,DME/P信号在第一邻道内泄露功率比DME/N信号泄露功率高约10 dB。

顾客授权行为对员工服务主动性的影响和作用机制研究

从资源保存理论视角出发,引入心理可得性和权力需要作为中介和调节变量,通过一项时间滞后的问卷设计和两项基于场景的实验设计,深入探讨了顾客授权行为对员工服务主动性的影响机制和作用边界。研究结论表明:顾客授权行为对员工服务主动性具有显著正向影响;心理可得性在顾客授权行为与员工服务主动性之间起中介作用;权力需要不仅调节顾客授权行为对员工心理可得性的直接作用,还进一步调节顾客授权行为通过员工心理可得性对其服务主动性的间接效应。

党组织嵌入公司治理对高管—员工薪酬差距的影响研究

收入分配制度的合理性是保障社会公平与正义的关键。然而,随着高管薪酬对企业绩效的作用逐渐凸显,高管薪酬不断提高致使高管“天价薪酬”成为普遍现象,引起理论界和实务界的广泛关注。基于我国特殊的公司治理制度,以2010-2021年我国沪深A股上市公司为研究样本对党组织嵌入公司治理是否影响以及如何影响高管—员工薪酬差距进行研究,发现党组织融嵌公司治理有助于抑制高管—员工薪酬差距,而且党组织融嵌程度越高,对高管—员工薪酬差距的抑制作用越强;此外,这种抑制作用对国有企业、董事长或总经理无政治关联、市场化程度低的企业更显著;进一步分析发现,党组织嵌入公司治理可以通过抑制管理层权力的扩大和降低企业风险进而抑制高管—员工薪酬差距。从中国特色的党组织嵌入公司治理视角探讨高管—员工薪酬差距的影响因素以及作用机制,对于丰富薪酬差距影响因素研究和党组织嵌入公司治理效应研究方面的文献,加强党组织建设、全面促进党组织建设与公司治理结构的有机结合、优化收入分配制度改革具有借鉴意义。

绿色变革型领导对员工自愿绿色行为的影响:自然情感联结与权力距离取向的作用

基于情感事件理论,探究绿色变革型领导对员工自愿绿色行为的影响机制。本研究分三个时点搜集了83个团队305份领导-员工配对数据,并进行多层次分析。结果表明:绿色变革型领导正向预测员工自愿绿色行为,员工自然情感联结在上述关系中发挥中介作用。此外,员工的权力距离取向正向调节绿色变革型领导与员工自然情感联结的关系,以及绿色变革型领导经由自然情感联结对员工自愿绿色行为的积极作用。本研究拓展了学界对员工自愿绿色行为激发因素的认识,同时为企业的绿色管理实践提供了新启示。

Chinese employees＇ leadership preferences and the relationship with power distance orientation and core self-evaluation

Informed by implicit leadership theories, this study investigates contemporary Chinese employees＇ preferences for paternalistic leadership （including three components： moral leadership, benevolent leadership and authoritarian leadership） and transformational leadership. It further examines the relationship between power distance orientation, core self-evaluation （CSE） and leadership preferences. The study finds that contemporary Chinese employees most prefer moral leadership, but are also highly receptive to transformational leadership. They prefer authoritarian leadership least. Moreover, preferences for authoritarian leadership are predicated on followers＇ power distance orientation. However, the opposite is true for moral leadership. CSE is positively related to followers＇ preference for authoritarian leadership, benevolent leadership and transformational leadership, but not except for moral leadership. A positive interaction effect is found between power distance orientation and CSE with regard to authoritarian leadership preference. The theoretical and practical implications of the findings are discussed.

随机空间几何构型下物联网络攻击节点定位

物联网各节点形成的空间几何构型随机性,决定了攻击节点的空间分辨率出现较大波动,继而影响攻击节点的定位精度。针对物联网下各节点形成的空间几何构型随机性,利用节点脉冲和功率的关联属性不受空间几何构型影响的特征,设计一种攻击节点定位算法。定位算法检测节点脉冲信号,设计最优功率关联算法,关联功率与脉冲的属性。通过关联属性构建节点距离测算定位方法。实验结果表明:文中的物联网攻击节点定位方法,在低、中、高阶三种攻击特征形式下,可以实时准确定位攻击性节点位置,具备较强的实用性。

基于高阶幂的单快拍LDACS系统波达方向估计

L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。

梯级泵站事故停机输水明渠水力过渡过程研究

为解决梯级泵站系统因超负荷、大流量、高水位运行出现垮渠、跳闸停机等事故,而导致水力过渡过程中出现进水前池被抽干或漫顶等问题,以甘肃省景泰川电力提灌二期工程长距离输水明渠为研究对象,在多梯级泵站事故停机产生溢流的工况下,基于Realizable k-ε和VOF模型进行数值模拟计算,分析景电二期工程1#~7#干渠在调蓄系统作用下,不同渠长、坡降的水面线以及水力振荡分布规律。结果表明:泵站停机后水位出现升降交替的水力振荡现象,影响各泵站波峰水位高度不一致的主要原因是渠道坡降;不同参数特征的渠道壅水波运动的回溯距离不同,溢流堰上发生溢流的时间主要在第一次水位振荡过程中。

新型动力轻型飞机飞行性能仿真评估

为评估新型动力轻型飞机的飞行安全性,基于民用航空器适航审定理念和方法,选取飞行关键的阶段,应用MATLAB软件模拟该型飞机起飞地面滑跑和起飞爬升性能,计算滑跑距离和爬升率。结果表明混合动力型轻型飞机的起飞地面滑跑距离缩短了10%,爬升性能提高了22%,同时混合动力型飞机对起飞机场的高度和温度环境适应能力也明显提升。该方法可作为混合动力轻型飞机适航审定中验证符合中国民航CCAR-23-R4规章第23.2115条款“起飞性能”和第23.2120条款“爬升”要求的一种方法。

一种基于谱分析的重力场统计特征建模方法

重力场的统计特征主要包括协方差(相关函数)、功率谱密度、球谐阶方差等参量,是从空域、频域和球谐域描述重力场变化规律的主要依据.本文以扰动位的距离倒数协方差模型为核函数,研究了一种能在不同重力场元之间自洽解析转换的统计特征建模方法.分别利用高分辨率的地面重力异常和实测航空重力梯度数据进行功率谱分析,结合EGM2008模型构建了3组重力场统计特征模型,分析了本文模型与经典模型的差异,并用于高频重力场随机模拟,验证了本文方法在不同频率区间建模的可行性和实用性.本文模型可用于重力梯度探测、高频重力场随机模拟、重力场推估等方面的定量分析,相关算法和思路也可为构建更精细的统计特征模型提供借鉴.