基于贡献率法的非线性工业过程在线故障诊断（英文）

Over past decades, kernel principal component analysis(KPCA) appeared quite popularly in data-driven process monitoring area. Enormous work has been done to show its simplicity, feasibility, and effectiveness. However, the introduction of kernel trick makes it impossible to directly employ traditional contribution plots for fault diagnosis. In this paper, on the basis of revisiting and analyzing the existing KPCA-relevant diagnosis approaches, a new contribution rate based method is proposed which can explain the faulty variables clearly. Furthermore, a scheme for online nonlinear diagnosis is established. In the end, a case study on continuous stirred tank reactor(CSTR) benchmark is applied to access the effectiveness of the new methodology, where the comparisons with the traditional linear method are involved as well.     

Mid-infrared scanning near-field optical microscope resolves 30 nm

We explore the performance of a scanning near-field infrared microscope, which works by scattering tightly focused CO₂ laser radiation (λ = 10  μ m) from the apex of a metallized atomic force microscope tip. The infrared images of test samples prove a spatial resolution of 30 nm and are free of topographical and inertial artefacts, thus they should be of great interest for practical applications. We also observe that the infrared contrast vanishes when the input beam polarization is orthogonal to the tip axis, in accordance with theoretical expectations for a mechanism of longitudinal field interaction.     

A new method to monitor adhesion and interfacial failure between polymers: rheo-photoacoustic FT-IR spectroscopy

Recently, a new rheo-photoacoustic Fourier transform infra-red (IR) cell has been developed to perform stress-strain measurements on polymeric materials. This technique is now being utilized to monitor interfacial failure between organic coatings and polymeric substrates; namely the interfacial failure between siloxane-polyethylene and poly(methyl methacrylate)-polyethylene systems is studied. As a result of interfacial failure, the intensities of substrate bands are enhanced. Signal leakage results from the formation of microvoids, which are monitored by electron microscopy. Analysis of the IR spectra demonstrates frequency shifting in the siloxane-polyethylene system, indicating chemical interactions between the two materials at the interface.     

基于改进TF-IDF算法的供电营销服务方法

针对传统的供电营销服务方式单一、服务成本高和电力客户体验差等情况,提出了一种基于改进TF-IDF算法的供电营销服务方法。首先,构建电力客户信息数据分类方法,基于电力客户的“行为-需求-价值”,建立电力客户信息数据分类;其次,构建特征标签指标集,采用多标签分类算法实现电力客户新增信息类别的标签识别;再次,充分计及电网规划、建设、运行维护等影响供电企业运营的因素,构建电力客户经济贡献画像模型,基于改进TF-IDF算法,形成全面的电力客户行为特征评估结果,并针对不同类型的客户,提供多种供电营销服务套餐;最后,通过对四川某供电服务区域的实例分析,验证了该算法的可行性和实用性,实际应用结果表明该方法在服务成本和客户体验方面优于传统的供电营销服务方法。     

Identification of Critical Lines and Nodes in Power Grid Based on Maximum Flow Transmission Contribution Degree

从结构性视角提出一种准确辨识电力网关键线路和节点的方法。该方法基于网络最大流和复杂网络理论,定义传输贡献度作为电力网关键线路和节点辨识依据,表征它们对实现电力网电能传输功能体现出的承载和贡献能力。该方法克服了现有研究中假设潮流沿着母线间最短路径传输的缺陷,依据网络整体结构考虑不同电源—负荷节点对间所有参与功率传输的路径;同时将电力网作为有向加权网络考虑,计及了线路最大有功传输容量约束,物理背景更符合电力工程实际。对IEEE 39节点系统进行仿真计算并将结果与现有方法对比,验证了所述方法的合理性和有效性。     

Partially linear model for harmonic contribution determination

Harmonic contribution determination is the premise on which the improvement of power system harmonic management is based. Calculating the harmonic impedance accurately is the key issue in harmonic contribution determination. The fluctuation method is a mature method for calculating the harmonic impedance in engineering applications. However, this method is ineffective when the background harmonic fluctuation is dominant. To make up the deficiency of the fluctuation method, the partial linear regression model for the harmonic impedance calculation is proposed in this paper, and then a two‐stage method is derived for the unbiased estimation of the model. The method proposed in the paper can calculate the harmonic impedance whether or not the background harmonic fluctuation is dominant, and then the harmonic contribution can be determined. The effectiveness of the proposed method is verified by the IEEE14‐bus system simulation and field test. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Technology interaction of Electrical Engineering

The paper reviews the global activities of the Technical Committee for History of Electrical Engineering (HEE) in Institute of Electrical Engineers of Japan (IEEJ) to discuss its future activities. Introducing HEE global activities in the Maui Meeting (MM) and International Conference on Electrical Engineering (ICEE), the paper discusses the framework of the International Joint Study Programme for History of Technology Interaction (IJSP/HTI) on the basis of its current study conducted by the Investigation Committee for International Joint Study for History of Technology Interaction (IC/HTI). It concludes the discussion with the view that the study of history could serve as a foundation for us to achieve global contributions in the field of engineering as well. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

面向分布式电源并网的多谐波源责任划分

充分考虑大量分布式电源接入电网导致背景谐波波动增大以及分布呈非对称特点的影响,提出了一种聚类算法与复合分位数回归相结合的多谐波源责任划分方法.首先,提出基于回归模型系数波动的有效数据选择方法对数据进行处理,在此基础上,采用主导波动量与OFMMK-means聚类算法结合的方法对波动的背景谐波电压进行聚类,并按照电压值分成...     

Series Resonance Fault Current Limiter (SRFCL) with MOV for LVRT Enhancement in DFIG-Based Wind Farms

Abstract—To reduce the negative effects of wind farms connection on power system stability, many countries have elaborated grid code requirements. Low-voltage ride through (LVRT) capability is the core of these requirements. This paper presents a framework to design and apply the series resonance fault current limiter (SRFCL) with a metal oxide varistor (MOV) for LVRT performance enhancement of doubly fed induction Machine (DFIG)-based wind farms. The main advantages of the SRFCL are simplicity, high reliability and automatically operation during fault condition for enhancing the LVRT performance. To demonstrate the capability of the SRFCL, a comparative study of the SRFCL and the bridge-type fault current limiter (BFCL) is performed. The study wind farm has been modeled with equivalent aggregated DFIG. Simulations were carried out in PSCAD/EMTDC environment. Simulation results demonstrate that the SRFCL provides a simple and effective solution to enhance the LVRT and reduce the fault current contribution of wind farms.     

水电机组超低频振荡贡献度排序及抑制方法研究

文章分析了超低频振荡产生机理,构造了哈密顿能量函数,研究了水电机组注入系统能量变化量,将水电机组对超低频振荡的贡献度排序。文中提出一种基于调速器附加阻尼控制的超低频振荡抑制方法,利用TLS-ESPRIT辨识算法和改进的混沌粒子群算法对附加阻尼控制器参数进行优化,实现了对水电机组调速器的相位补偿,抑制了超低频振荡。最后,在改进的四机两区域模型中进行了仿真验证,结果表明所提出的方法能有效评价水电机组对超低频振荡的贡献度,抑制超低频振荡。