Optimized Energy‐Saving Speed Profile in Linear‐Motor Railway System

The most striking characteristic of linear‐motor railway system is that the structure consists of a primary and secondary linear induction motor (LIM). The primary side of the LIM is installed in a rolling stock, and the secondary side of LIM is installed on the track. The magnetic attractive vertical force produced by the LIM increases the running resistance since this force is in the same direction as the gravitational force due to which rolling stocks gain weight virtually from the track side of view. In addition, the efficiency of the LIM has different characteristics of efficiency compared with the rotary motor. Previous studies have focused on the design method of LIM to improve motor efficiency and decrease energy consumption. However, it is a well‐known fact that this kind of approach requires hardware renewal which requests large amount of investments. The purpose of this study is to analyze these characteristics of LIM effects and design the optimal speed profile to minimize the energy consumption as a linear‐motor railway system. This smart and economic energy‐saving approach is based on the optimization of speed profiles of the linear‐motor railway system using dynamic programming.     

Study on Lightning Protection Measures for Distribution Lines and Customer Equipment against Back Flow Lightning Current from Radio Communication Station

Recently, with the expansion of communication network areas, the number of radio communication stations built in the neighborhood of customer houses has increased. If lightning strikes a communication radio tower, part of the lightning current flows into the distribution line and into customer houses. This may cause the failure of distribution lines or customer equipment. To protect distribution lines and customer equipment from lightning faults, it is necessary to analyze the surge phenomena in distribution lines and customer equipment and take appropriate protection measures. In this study, we examined the effect of lightning protection measures for distribution lines and customer equipment against lightning strikes to a communication tower. First, using an actual‐scale test distribution line, we measured the lightning current flowing into distribution lines and customer equipment. Second, we quantitatively examined the effect of lightning protection measures by lighting surge analysis while changing each parameter. From the experimental and analytical results, we show that the proposed protection measures can reduce the lightning current flowing into distribution lines and customer equipment.     

A Three‐Position Swing Electromagnetic Actuator with an Integrated Eddy Current Brake for Suppression of the Operating Time and Improvement of the Stopping Accuracy

A closed‐loop control system is commonly used in electromagnetic actuators to ensure operating performance. However, this system frequently leads to high costs. We developed a swing electromagnetic actuator with an integrated eddy current brake to reduce the operating time and improve the stopping accuracy. The developed actuator is a three‐position cylindrical actuator moving within a ±120º angle without closed‐loop control. The rotor is composed of a bulk and thin metal laminations and the stator has three sets of pairs of coils. The rotor is stopped at an intermediate position by magnetic force generated by the coils. This paper describes the electromagnetic design and its evaluation by using an FEM simulation to predict its operating characteristics and measure its performance on a test bench. The superiority of our actuator design is verified by comparing these measurements. The operating time is reduced to one‐sixth of that of a laminated rotor and the over travel is compressed to zero. In addition, this actuator has the advantage that it is electrically robust against variations in the power supply.     

单腔与多腔放大式高效耗能黏滞阻尼墙性能研究

针对阻尼墙耗能效率问题提出横向位移放大与纵向多腔放大概念,并以此设计了3种高效耗能黏滞阻尼墙装置,即单腔放大式黏滞阻尼墙(SADW)、多腔放大式黏滞阻尼墙(MADW)和多腔相对放大式黏滞阻尼墙(RADW)。根据3种阻尼墙的构造特点,分析了横向位移放大系统与纵向多腔放大系统的耗能效果,提出了阻尼力及耗能理论计算式。取SADW为代表与普通黏滞阻尼墙(VDW)进行试验对比研究,分析在不同试验工况下SADW的滞回耗能能力。结果表明：SADW的滞回曲线较VDW更加饱满,耗能效果更为显著;将阻尼力-位移试验结果与理论曲线进行了对比,两者基本一致,阻尼力相差6.35%,理论滞回模型能较好模拟试验结果。同时,建立了30层混凝土框架核心筒结构进行地震时程响应分析,对比VDW和3种高效黏滞阻尼墙对该结构的减震效率,4种减震方案的结构附加阻尼比分别为0.71%、3.38%、6.22%、735%,附加阻尼比放大倍数分别为4.5、7.8、9.0,进一步验证了所提出的3种高效耗能阻尼墙具有良好的减震效果。     

隔震支座沿曲面布置的隔震结构动力响应及振动台试验研究

针对超设计基准地震作用下隔震层存在过大变形、影响结构安全等问题,基于已提出的一种隔震支座沿曲面布置的隔震结构,通过变形和受力分析建立了简化双自由度动力模型,得到了系统关键动力参数,即公转频率、自转频率及单摆频率等的计算式.进一步给出了结构响应传递函数,明确了结构高宽比、曲面角度、隔震层阻尼比对结构响应的影响规律,并基于...     

Research on the Characteristic Change in an Inductive‐Coupling‐Type Contactless Power Transformer for a Railway According to the Core Shapes and Misalignment Utilizing a T‐Type Equivalent Circuit

Although an electric railway is an ecological transportation system, there are some obstacles when an electric railway is installed: the high cost for installation and the detrimental effect on the environment. A contactless power transfer system (CPT system) is a solid solution for these obstacles. However, a CPT system for a railway application needs to have a high capacity and a tolerance to the misalignment of the coils. In this paper, inductive power transfer theory, which is able to transfer a greater amount of energy than the electromagnetic resonance method is chosen, and its tolerance to the misalignment is our focus. The authors measure various core shapes, and their coupling coefficients, leakage inductances, and excitation inductances according to the misalignment are obtained with a finite element method (FEM) analysis. By using these parameters, the transmitted power and efficiency are calculated by two equivalent circuits: the S/S circuit and the S/P circuit. Finally, by comparing the parameters and transmitted power of each core shape and circuit, the authors show that the circular core can transfer 100 kW of energy for a misalignment of 300 mm.     

组合基础隔震房屋模型振动台试验研究

基础隔震能有效地降低上部结构的地震作用,但不同的隔震体系,隔震效果不同.本文根据叠层橡胶支座和滑板摩擦隔震支座的特点,提出组合基础隔震系统,以中国和日本国的在建隔震房屋为工程背景,进行了组合基础隔震房屋模型和基础固定房屋型模拟地震动振动台试验,并对两种试验结果进行了能量分析,分析结果表明组合基础隔震系统中叠层橡胶支座能自动复位,滑板摩擦隔震支座具有良好的耗能能力,隔震效果明显,组合基础隔震系统是一种简单、经济、有效具有广泛应用价值的基础隔震形式.本文获得的大量振动台试验结果可以为隔震设计和加固中使用这种隔震系统及进一步的理论分析提供重要依据.     

Trivalent-Cation-Substituted Calcium Oxyhydroxyapatite

Synthesis of stable oxy- and oxyhydroxyapatkes [(Ca,M)-Ap] was attempted by substitution of Ca²⁺ with M³⁺ (M = Al, Y) assuming the composition Ca_10-xM_x(PO₄)₆(OH)_2-xO_x. Yttrium-calcium oxyhydroxyapatite was successfully obtained. Its structure was analyzed and confirmed by X-ray diffraction and infrared spectroscopy. Dielectric dispersion and absorption were not so distinct in (Ca,Y)-Ap as in hydroxyapatite (Ca-Ap). The ac electrical conductivity of (Ca_10-x,Y_x)-Ap was found to decrease with increasing x. These results are discussed in terms of a proposed charge transport mechanism.     

一种聚合阻尼耗能结构理论模型与地震响应研究

针对高层框架核心筒剪力墙结构体系在地震作用下层间位移小,阻尼器难以发挥较好耗能作用的问题,基于内核心筒和外围框架结构的变形特点,在框架核心筒的聚合变形位置设置位移放大型高效阻尼器（SDA）,形成了聚合阻尼耗能结构体系（NSD）。分析了位移放大阻尼器的耗能力学性能,提出了普通型黏滞阻尼器（VD）和放大型黏滞阻尼器的阻尼力及耗能理论公式。设计制作了 3 倍位移放大型黏滞阻尼器和普通黏滞阻尼器的试验模型,进行正弦波往复加载试验,得到不同试验工况下黏滞阻尼器的滞回耗能曲线,并将理论曲线与试验曲线进行了对比,验证了力学模型的正确性;对比 SDA 与 VD 的耗能效果,得出在相同位移下,SDA 比 VD 滞回曲线更加饱满、耗能更为显著。进一步对一栋聚合阻尼耗能结构进行地震响应分析,结果表明与传统结构相比,聚合阻尼耗能结构具有良好的减震性能。     

Evaluation of Automatic Train Operation Design for Energy Saving Based on the Measured Efficiency of a Linear‐Motor Train

Recently, interest in energy savings in railway systems has been increasing because of its environment‐friendly aspects, for example, CO₂ emissions. In this paper, the authors propose a scheduling and control system for automatic train operation (ATO) that saves energy. This research in ATO concentrates on the optimization of speed profiles to save energy. The differences in this system from previous work are substantiative experiments on the track and a design that explicitly considers the following energy‐saving operations. First, coasting is installed in speed profiles and maximum speed is decreased by jerk regulation. Second, power‐limiting braking is used in the braking section and regenerative energy is increased. To achieve this braking efficiency, notch operations are updated. Finally, second‐order scheduling is achieved by high speed control using ATO. For the experiments on the track, the efficiency of a linear‐motor train was measured in a pre‐experiment and used to perform accurate numerical calculations. In conclusion, the numerical study shows an energy efficiency increase by 7.3% and the plan for further experiments is determined.