Distributed generation of electric energy in traction power-supply systems of railways based on wind-power plants

The assessment of the possibility to use the potential of wind energy for power supply of the traction railway network in the context of the area of Karatau in the southern region of the Republic of Kazakhstan, the main wind-energy characteristics of the region are determined. An comparison of the program is presented with the results of statistical processing of the data sets on the long-term monitoring of the wind indicators of the investigated region with wind-speed determination during a month, mathematical expectations, law of the probability density of wind-speed distribution for a month, diagrams of wind distribution according to days within a month, instantaneous values (gusts) of wind speed for 24 h, and average wind speed by time of day for a month. A diagram of a traction power-supply system with distributed energy generation is given based on wind-power plants, their equivalent circuit and design including the wind generators, rectifying and inverting converter units, as well as the electric-energy accumulator with the direct current converter. Theoretical dependences are obtained to determined additional electric-energy losses in the traction network during redistribution of energy in the traction power-supply system from the main traction substations to energy-storage units at the “wind” traction substations during periods of an unfavorable wind situation in the region. The operation regimes of the electric-power facilities incorporated into the traction powersupply system and “wind” traction substations are described taking into account the pure traction mode from the wind electricity generator, power supply of trains from energy-storage units under conditions of the insufficient wind force, and energy-recovery regimes during braking of the trains, as well as with qualitative determination of their operating parameters. The main electrical characteristics of the equipment of the “wind” traction substations are determined.     

Stationary system based on capacitive energy storage units to accumulate energy recuperation of metro electric rolling stock

The most prospective examples of using capacitive energy storage units in the traction power-supply system are described. Functions of the units are defined. A schematic diagram and basic technical characteristics of the unit are given with reference to the metro. The preliminary technical and economic efficiency of the capacitive energy storage application for a particular line of the Moscow metro is shown.     

不同位置再生制动能量吸收装置下直流牵引网潮流计算对比分析

城市轨道交通列车运行时广泛采用再生制动方式,再生制动能量回馈至接触网后被附近运行列车吸收,剩余再生制动能量通过再生制动能量吸收装置吸收以限制接触网压过高。目前,再生制动能量吸收装置安装位置主要有列车安装和变电所安装,不同安装位置下,列车再生制动能量引起对直流牵引供电系统的影响不同。分别建立两种再生制动类型下直流牵引供电系统潮流计算模型,仿真分析了多列车多变电所并列运行下,不同位置再生制动能量吸收装置对牵引供电系统电压、电流及再生制动功率分配的影响。     

The efficiency of condenser energy-storage systems for underground wagons

A procedure for determining the efficiency of condenser energy-storage systems that are installed in underground cars for receiving electric power for traction electric cars working in a recuperative-braking regime is proposed. It was suggested to carry out comparative analysis of the efficiency of energy-storage systems on the basis of the following parameters: index of electric-power recovery in a full start-brake cycle of the wagon operation, relative determination of electric-power recovery in the braking regime and electric-power loss in the active regime of car operation, index of electric-power recovery in electrodynamic braking of traction electric cars, and relative evaluation of the mass of energy-storage systems. It is proposed to analyze the efficiency of energy-storage systems taking into account their design features. Energy-storage systems can be manufactured in a monoblock or stepped design. The proposed procedure of comparative analysis of the energy and mass-dimensional characteristics of underground cars with energy-storage systems allow their operation to be evaluated with a minimum number of source data. Installation of energy-storage systems increases the mass and energy expenditure during wagon operation, but this loss is significantly less than the energy volume recovered with an energy-storage system in a regime of recuperative braking of traction electric cars. Energy-storage systems allow one to create effective systems of autonomic recuperative braking on underground cars. A stepped design of energy-storage systems decreases their mass-dimensional characteristics and increases energy efficiency. The only real disadvantage of energy-storage systems preventing their use is their large size.     

Adaptation of a traction DC power system for high-speed traffic

Ways to develop and improve traction power-supply systems and adapt them for high-speed highways are considered. One way to improve a traction power-supply system and make it more efficient is to increase the nominal voltage in the dc traction network up to 24 kV. This allows one to increase the throughput and carrying capacities of railways, increase the distance between substations, reduce the cross section of traction-network wires, and significantly reduce power losses in power-supply facilities. All this, alongside the absence of unbalanced supply voltage and inductive losses, as well as a significantly lower electromagnetic action on the infrastructure under dc conditions, results in a greater efficiency than in the case of any alternating- current traction power systems of alternating current. A mathematical model of dynamic electromagnetic processes in electrical circuits with semiconductor converters is fleshed out. Analysis and synthesis of electromagnetic processes and the main characteristics of multipulse converters, as well as a comprehensive technical and economic comparison, shows that 24-pulse rectifying circuits with a serial connection of threephase bridge are most efficient for these systems. These rectifiers provide an improvement in the quality of electrical energy not only for the primary power-supply system, but also for the traction network. They allow one to use simpler and more economical active-passive smoothing filters that provide the electromagnetic compatibility (EMC) of a new traction dc power system with the communication and railway automation facilities. In addition, the use of 24-pulse rectifiers can allow one to significantly reduce the consumption of reactive energy, reduce power losses in a traction network, and increase the efficiency of traction substations.     

Control of urban rail transit equipped with ground-based supercapacitor for energy saving and reduction of power peak demand

An energy storage system based on Supercapacitor (SC) for metro network regenerative braking energy is investigated. The control strategy according to the various power requirements in metro line and differing characteristics of these storage devices are proposed to manage the energy and optimize the power supply system performance. In order to estimate the required energy storage system (ESS), line 5 of Beijing metro network is modeled through a novel approach, in different running interval conditions based on the real data obtained from Beijing metro office. A useful method is proposed to predict the instantaneous regenerative energy which is delivered to each substation before applying ESS and based on that the ESS configuration for each substation is determined. A simplified mathematical model of the whole metro network has been developed and the main features of the control strategy have been developed. Numerical simulations show the efficacy of suggested control and the energy saving obtained for metro trains.     

A method for improving the energy efficiency of an alternating current electric locomotive in the regenerative braking mode

A method for improving the power factor of an ac locomotive with the commutator motor operating in the regenerative braking mode is proposed. The method improves the control system algorithm of the power converter. The new switching method of inverter thyristors regulates the curve of the instantaneous power during the main switching. It allows reducing the period in which the energy flow passes to the locomotive, leading an increase in the average value of the instantaneous power. A “traction substation–electric traction network–locomotive in the regenerative braking mode” mathematical model is presented to verify efficiency of the method. The model consists of several interacting electric power substations, a section of electric traction grid, a locomotive power transformer, a four-zone inverter, a control system of reversible converter, and a dc circuit. The model is realized in the OrCAD software.     

树形双边贯通供电方案及其应用研究

树形双边贯通供电方案能够取消牵引变电所出口和分区所处的电分相,提高系统的供电能力和再生制动能量利用率.介绍了树形双边供电方案的构造;针对树形双边贯通供电方案,以复线直接供电方式为例,推导了牵引网双边供电区间在复线牵引网上下行不并联、末端并联、全并联,以及端头供电臂单边供电等情况下的牵引网阻抗模型;以牵引变电所为单元,构...     

Design and Efficiency Evaluation of a High‐Efficiency Induction Motor for Railway Traction

In commuter trains, a large portion of the energy consumption is a result of losses from traction motors. Therefore, highly efficient traction motors would be very effective for saving energy. We developed an induction motor with a high efficiency of 95.5%. This paper presents the design and an efficiency evaluation of a prototype machine.     

Environmentally‐friendly Aspects and Innovative Lightweight Traction System Technologies of the Shinkansen High‐speed EMUs

In 1964, the Tokaido Shinkansen marked the start of the world's first commercial service high‐speed railway that operates at over 200 km/h. Since then, the Tokaido Shinkansen has demonstrated successful business and technological advancement. With the speeding‐up of the Shinkansen, environmental matters such as noise and vibration have become critical issues. Measures taken to counter noise and vibration—such as weight reduction and aerodynamics—also effect global environmental measures to reduce energy consumption and CO₂ emission. With the introduction of the Series 300, there was a system change of applying an AC drive system, and the lightweight body realized performance improvement over the earlier Series 0. The high‐speed EMUs have readily taken advantage of technological innovation such as those achieved in electronics technology. In particular, an innovative AC drive system comprising a power converter with a GTO thyristor and asynchronous motors realized a high‐performance and lightweight traction system for high‐speed EMUs in the 1990s. Furthermore, recent innovations in electronics technology, such as low switching loss power devices and high‐power permanent magnets, have improved the AC drive systems of the high‐speed EMUs of the 21st century. This article starts out by introducing environmentally friendliness of the Shinkansen trains in terms of low energy consumption by means of traction system change, and then proceeds to describe the recent technological innovations that have given birth to lightweight traction systems, such as the Permanent Magnet Synchronous traction Motor (PMSM) and power converters with train‐draft‐cooling systems. The article concludes by summing up the environmentally friendly aspects of the Tokaido Shinkansen. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Developing the algorithm and device for automatic connection of an out-of-phase standby power-supply system without a disruption of load powering

The processes of switching from an AC (50/60 Hz) main power-supply system to a standlby system in the presence of different initial phases and a certain delay in switching are considered under the following loads: an asynchronous motor and a power transformer. A new device and algorithm for switching without time delay and, consequently, without load voltage surges are proposed. Switching of power-supply systems using the proposed device and the influence of the switching time on the capacity of the energy-storage unit of the device are considered. The potentialities of a multifunctional device for connecting a standby power-supply system are described.     

Electromagnetic compatibility of a traction power-supply system and infrastructure elements in areas with high traffic

Electric traction systems are improved as part of the process of updating the entire system that converts the power that is consumed by the transportation process. Application of dc converters to a three-phase alternating current, the use of thyristor converters of the dc voltage level, the creation of highly efficient algorithms for computer control of electric-power conversion, and substitution of commutator dc motors for brushless three-phase ac motors lie at the core of technological improvement of electric traction systems and are now widely used in a number of industrialized countries. This paper proposes new traction power-supply systems for areas with high traffic, which require additional wires to be laid and multiconductor lines to be used. The requirements are formulated, and a methodology for grounding the electromagnetic compatibility of multiconductor lines of traction power supply and infrastructure elements is discussed. It is shown that electromagnetic coupling of lines takes place under conditions of both electric and magnetic effects between two or more electrically long lines. In electrically long lines, the voltages and currents cannot be considered independent of each other. They are interconnected through the impedance of the respective line (similarly to how electrical and magnetic fields of electromagnetic waves are linked with each other through the impedance of space). The studies and analysis that were carried out showed t6hat it is possible to simulate the propagation of electromagnetic waves along multiconductor traction power-supply lines, which allow determining not only the currents and voltages at any given point of a multiconductor line, but also simultaneously induced voltages at an adjacent line. All this allows highly accurate checking of the electromagnetic compatibility of the traction network and longitudinal power supply lines with communication lines and track circuits in areas with high traffic.     

计及特征次谐波治理的铁路网侧储能系统控制策略

针对电气化铁路节能增效及谐波治理问题,提出一种考虑特征次谐波治理的铁路牵引网侧储能系统控制策略。首先,分析牵引网侧储能系统接入方案并对其工作模态进行划分;其次,根据牵引负荷特征次谐波分布规律,推导网侧储能系统削峰填谷及特征次谐波治理方法;然后,提出一种计及网侧特征次谐波抑制的超级电容储能系统控制策略;最后,通过多工况下仿真测试,验证了所提策略的可行性。结果表明,所提策略能有效回收再生制动能量,减小网侧功率波动,抑制网侧特征次谐波。     

全并联AT供电方式下供电臂保护控制方案

首先分析了高速铁路中采用的全并联AT(autotransformer)供电方式的特点,在分析传统保护控制方案不足的基础上,提出了一种以供电臂为单元的保护控制方案.在该方案中主要讨论了AT自耦变压器保护功能的实现原理,以及供电臂发生永久性故障时供电臂自动控制方案的实现原理.以供电臂为单元的保护控制方案借助远动通道实现了牵引变电所、AT所和AT分区所之间的信息共享,提高了供电可靠性和供电自动化程度.     

列车再生制动能量管理及控制系统研究

为回收利用交流电气化铁路列车产生的再生制动能量,研究了再生制动能量管理及控制系统.提出一种基于牵引负荷状态的能量综合管理策略,以牵引变压器两供电臂负荷功率为信息载体表示系统的不同工作模式,多种工作模式可相互切换.在混合储能装置内部功率分配中,通过引入锂电池荷电状态SOC(state of charge)及超级电容中间调...     

Calculation of metro traction power supply considering partial recuperation currents outputted by Rusich-type railway cars

Algorithm of calculation of metro traction power-supply system was considered considering partial recuperation currents output to traction system by modern recuperation rolling stock with asynchronous traction drive and microprocessor-based control system.     

计及特征次谐波治理的铁路网侧储能系统控制策略

针对电气化铁路节能增效及谐波治理问题,提出一种考虑特征次谐波治理的铁路牵引网侧储能系统控制策略。首先,分析牵引网侧储能系统接入方案并对其工作模态进行划分;其次,根据牵引负荷特征次谐波分布规律,推导网侧储能系统削峰填谷及特征次谐波治理方法;然后,提出一种计及网侧特征次谐波抑制的超级电容储能系统控制策略;最后,通过多工况下仿真测试,验证了所提策略的可行性。结果表明,所提策略能有效回收再生制动能量,减小网侧功率波动,抑制网侧特征次谐波。     

地铁车辆异步电机矢量控制系统的研究

地铁乍辆由于车站间距短,加速和制动频繁,要求牵引电机容量大、转速高,因而对电机的控制要求也高.目前地铁牵引系统多采用三相交流异步电机变压变频牵引技术.通过对上海地铁1号线直改交车辆牵引系统主同路的分析,以及对异步电机转子磁场定向的SPWM矢量控制的研究,搭建了基于Matlab的Simulink仿真模型,并进行了实验测试,结果表明该控制系统有良好的动态性能和控制性能.     

基于电力系统能效评估的蓄能用电技术节能评价及优化

蓄能用电技术的调峰特性使得其应用比较广泛,但对于蓄能用电技术的节能效果却少有量化的分析。提出、推导了电力系统能效评估的节点煤耗率指标,基于交流最优潮流进行了节点煤耗率的求解;基于节点煤耗率理论,提出了蓄能用电技术节能评价的节点用电煤耗指标,利用该指标构建并研究了蓄能用电的节能优化控制模型。IEEE14节点系统算例分析了节点煤耗率指标的时间空间特性以及用于电力系统能效评估的可行性;冰蓄冷系统算例验证了该评价方法和控制策略的可行性,蓄能用电节能优化控制可有效降低系统的整体能耗。