COMPLEX POWER OF HERMITE OPERATOR

In this paper the authors define complex power of Hermite operator and give some applications in Riemann Zeta function.

An In-Depth Study of Complex Power System Dynamic Behavior Characteristics for Chinese UHV Power Grid Security

In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.

Optimized Complex Power Quality Classifier Using One vs. Rest Support Vector Machines

Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power quality classification techniques focused on single power quality events and did not include an optimal feature selection process. This paper presents a classification system that employs Wavelet Transform and the RMS profile to extract the main features of the measured waveforms containing either single or complex disturbances. A data mining process is designed to select the optimal set of features that better describes each disturbance present in the waveform. Support Vector Machine binary classifiers organized in a “One Vs Rest” architecture are individually optimized to classify single and complex disturbances. The parameters that rule the performance of each binary classifier are also individually adjusted using a grid search algorithm that helps them achieve optimal performance. This specialized process significantly improves the total classification accuracy. Several single and complex disturbances were simulated in order to train and test the algorithm. The results show that the classifier is capable of identifying >99% of single disturbances and >97% of complex disturbances.

NEW METHOD TO ESTIMATE SCALING EXPONENTS OF POWER-LAW DEGREE DISTRIBUTION AND HIERARCHICAL CLUSTERING FUNCTION FOR COMPLEX NETWORKS

A new method and corresponding numerical procedure are introduced to estimate scaling exponents of power-law degree distribution and hierarchical clustering function for complex networks. This method can overcome the biased and inaccurate faults of graphical linear fitting methods commonly used in current network research. Furthermore, it is verified to have higher goodness-of-fit than graphical methods by comparing the KS （Kolmogorov-Smirnov） test statistics for 10 CNN （Connecting Nearest-Neighbor） networks.

An Analytical Model of the Power Law Distributions in the Complex Network

It is known that complex networks in nature exhibit some significant statistical features. We notice power law distributions which frequently emerge with respect to network structures of various quantities. One example is the scale-freeness which is described by the degree distribution in the power law shape. In this paper, within an analytical approach, we investigate the analytical conditions under which the distribution is reduced to the power law. We show that power law distributions are obtained without introducing conditions specific to each system or variable. Conversely, if we demand no special condition to a distribution, it is imposed to follow the power law. This result explains the universality and the ubiquitous presence of the power law distributions in complex networks.

A novel decomposition and coordination algorithm for complex networks and its application to power grids

To analyze and control complex networks effectively, this paper puts forward a new kind of scheme, which takes control separately in each area and can achieve the network’s coordinated optimality. The proposed algorithm is made up of two parts: the first part decomposes the network into several independent areas based on community structure and decouples the information flow and control power among areas; the second part selects the center nodes from each area with the help of the control centrality index. As long as the status of center nodes is kept on a satisfactory level in each area, the whole system is under effective control. Finally, the algorithm is applied to power grids, and the simulations prove its effectiveness.

基于暂态关键特征逻辑推理的复杂电网响应驱动暂态稳定性判别

暂态稳定实时性判别是响应式稳定控制的核心,新能源和直流输电并网下电网的结构、运行和响应特征复杂程度骤增,现有实时性判别方法的准确性和泛化性面临挑战。该文针对含新能源和直流输电的复杂电网暂态稳定性,提出了一种基于可量测暂态能量特征的自适应逻辑推理判稳方法,实现无电网模型依赖且具有可解释性的实时性稳定性判别。首先,基于发电机转子运动的能量关系,结合特勒根定理构建了面向复杂电网响应信息的能量函数并论证了其守恒性;然后,根据系统动能-势能能量转换特征定义了稳定预判因数,并结合最大功角差构成了判稳关键特征量,提出了基于自适应模糊推理神经网络(ANFIS)的关键特征量与稳定状态之间的映射模型,实现了暂态稳定性实时推理评估;最后,在简单系统中量化分析了关键特征量与系统稳定性间的关系,并在修改后含新能源与直流输电的IEEE10机39节点系统中验证了该文所提方法的有效性与泛化性。

A Novel Low-Complexity Low-Latency Power Efficient Collision Detection Algorithm for Wireless Sensor Networks

Collision detection mechanisms in Wireless Sensor Networks (WSNs) have largely been revolving around direct demodulation and decoding of received packets and deciding on a collision based on some form of a frame error detection mechanism, such as a CRC check. The obvious drawback of full detection of a received packet is the need to expend a significant amount of energy and processing complexity in order to fully decode a packet, only to discover the packet is illegible due to a collision. In this paper, we propose a suite of novel, yet simple and power-efficient algorithms to detect a collision without the need for full-decoding of the received packet. Our novel algorithms aim at detecting collision through fast examination of the signal statistics of a short snippet of the received packet via a relatively small number of computations over a small number of received IQ samples. Hence, the proposed algorithms operate directly at the output of the receiver's analog-to-digital converter and eliminate the need to pass the signal through the entire. In addition, we present a complexity and power-saving comparison between our novel algorithms and conventional full-decoding (for select coding schemes) to demonstrate the significant power and complexity saving advantage of our algorithms.

Optimal power allocation for complex field network coding scheme with the K-th best relay selection

Wireless relay and network coding are two critical techniques to increase the reliability and throughput of wireless cooperative communication systems. In this paper, a complex field network coding （CFNC） scheme with the K-th best relay selection （KBS） is proposed and investigated, wherein the K-th best relay is selected to forward the multiplexed signal to the destination. First, the upper bound of the symbol error probability （SEP）, the diversity order, and the coding gain are derived for the CFNC scheme with KBS. Then, the coding gain is utilized as the optimized cri- terion to determine the optimal power allocation. It is validated through analysis and simulation that the CFNC scheme with KBS can achieve full diversity only when K=I, while the diversity order decreases with increasing parameter K, and the optimal power allocation can significantly improve the performance of the CFNC scheme with KBS.

在“行政效率”与“地方文化网络”之间:乡镇基层治理的综合情理与实践智慧

“情理”在中国基层社会治理中有着举足轻重的结构位置,但其具体实践依然有进一步研究的空间。浙北W镇综合行政执法分局的基层实践,根据基层行政执法部门的行动指向和实际控制权两个维度,采取了秉持人文关怀、外借权威、联合避责等行动策略,以应对治理场景下的工作压力和提高治理效果。执法部门的“情理”运作有着深刻的实践逻辑,即在提升政府治理效能、符合社会期待、维持部门组织自主性、降低治理风险性等多维的情理维度之间寻求平衡,这是“行政效率”与“地方文化网络”动态交互而成的实践智慧。

机电顾问视角下城市综合体电气设计的思考

结合杭州某一城市综合体项目,分析了城市综合体建筑的电气设计的重点、难点及关键技术,归纳不同餐饮形态的负荷指标,并总结出经验取值范围;提出商业综合体的两种高压供电形式,并给出了不同选用原则;总结了酒店柴油发电机的设置原则;结合以往工作经验,提供了大型设备运输方案。

基于降维粒子群的大电网断面功率极限计算方法

随着电力系统的发展,系统运行方式日益复杂。为了提高电力系统运行安全水平,提出一种基于降维粒子群的大电网断面功率极限计算方法。首先综合考虑大电网静态安全稳定约束和暂态稳定约束,建立断面功率极限计算模型;然后,提出了基于功率灵敏度的降维粒子群算法,根据功率灵敏度和聚合系数对可调节发电机组进行分群处理,利用降维粒子群算法计算得到了极限功率、发电机组功率调节量以及极限功率制约因素,实现了大电网断面功率极限的快速寻优。最后在我国某地区2128节点电网和我国某跨区12643节点联网中验证了该方法的有效性和正确性。

复杂地形对风速廓线的影响

随着风电利用的发展,越来越多的风电场建立在复杂地形的山区,为了更好地进行风能评估和风电预报,就需要了解复杂地形对风速廓线的影响。本文基于薄翼理论和湍流边界层扰动的线性化理论,采用两层模型对坡度较小的山地在其二维横截面上的风廓线进行了预测,该模型能够较为准确地预报地形、压力、稳定度对风速增速的影响,但对于三维地形或其他因素产生的风速的复杂变化,需要进一步将其扩展至三维,并结合数值模拟进行研究。

含复杂电源结构省级电力系统电力电量平衡方法

随着风电、光伏大规模接入电力系统,为计及其出力的不确定性,需要以年为尺度、小时为颗粒度进行电力电量平衡分析。以含复杂电源结构、内部断面限制、外部交直流受电的省级电力系统为对象,提出了一种新的电力电量平衡分析方法。该方法以日周期进行滚动平衡分析,针对特定日:通过对各分区同类电源进行聚合以简化问题、降低求解规模;通过构建火电开机优化模型以在考虑断面限制下以均衡开机为原则确定各分区火电开机容量;通过合理设计优化调度模型以在满足不同分区同类电源均衡调度、同一分区不同种类电源顺序调用原则下实现电力平衡计算。算例以实际省级电力系统数据为基础,验证了该方法的有效性、合理性、快速性。

随机数据丢包情况下组网雷达功率分配算法

在组网雷达系统中,由于节点间通信信号传播存在路径衰落等问题,雷达量测数据与资源调度数据的传输接收存在随机性。引入随机丢包变量,用以表征数据接收的随机性,建立丢包状态下组网雷达多目标跟踪功率分配模型,推导了该模型多目标跟踪误差期望下界,最终建立了总功率一定条件下,以最小化目标威胁度加权期望跟踪误差下界的数学优化模型,并通过凸优化算法求解。仿真结果表明,与不考虑随机丢包变量的功率分配算法相比,所提算法在多种场景下均能有效提高目标跟踪精度。

基于新型编码解码网络的复杂输电线识别

构建新型编码解码网络实现图像中多根交叉复杂输电线的高精度快速识别.为了减少网络参数,编码器取常规MobileNetV3的前16层,并且采用坐标注意力机制代替常规MobileNetV3的挤压和激励注意力机制,获取特征图的通道信息和位置信息;解码器通过金字塔池化模块获取输电线多尺度特征信息,提高识别精度;采用跳跃链接将编码器第2、4、7、11和13层特征图经锐化核卷积处理后分别与解码器的特征图堆叠,加强复杂输电线边缘特征提取;引入混合损失函数解决图像中输电线像素少、背景像素多的类别不平衡问题;利用迁移学习加快网络训练速度.实验结果表明,新型编码解码网络的平均像素精度(MPA)、平均交并比(MIOU)和识别速度分别为92.18%、84.27%和32帧/s,优于PSPNet、U2Net和其他输电线识别网络的.

工程教育专业认证背景下电力电子课程实验教学研究

解决复杂工程问题能力是工程教育认证的核心能力指标,为通过实验来提升学生解决复杂工程问题的能力,文章以电力电子技术课程中三相桥式整流实验为例,将硬件平台实验与软件平台仿真融合,分别从复杂问题提出、实验设计、实验分析多个环节出发,对基于解决复杂工程问题能力的实验教学进行了研究。该研究能够加强学生对复杂工程问题的理解,培养学生解决复杂工程问题的能力,对工程教育专业认证背景下实验教学改革具有一定的借鉴意义。

基于复杂网络理论的船舶电网脆性源辨识方法

[目的]针对船舶电网关键元件辨识方法的考虑角度单一,未计及节点的局部和全局特征、对节点承载负荷的重要度考虑不足等问题,提出一种基于复杂网络理论的博弈组合赋权脆性源辨识方法。[方法]船舶电力系统发生中断和连锁崩溃的内在机理是其本身具有脆性。首先,从脆性角度出发,基于复杂网络理论建立节点度、特征向量中心性、节点凝聚度、接近中心性、脆性电气介数等5项指标;然后,提出博弈组合赋权法,以纳什均衡为协调目标,确定直觉模糊层次分析法(IFAHP)和熵权法(EWM)的最优组合权重,并综合赋值5项指标以得到综合脆性指标;最后,利用典型四电站环形船舶电网,验证该脆性源辨识方法的有效性和可行性。[结果]根据不同脆性指标的网络效能,得到了4个等级的脆性源。对比结果表明,所提方法可以更全面合理地辨识脆性源。[结论]研究成果可为船舶电网连锁故障的预防控制提供有效指导。