牵引供电方案设计中谐波谐振问题研究

为了评估牵引供电系统的谐波谐振特性,从牵引供电系统设计角度出发,建立牵引供电系统谐波特性仿真模型和牵引负荷谐波发射模型。研究牵引供电方案中外部电源系统短路容量大小和馈线电缆长度变化对牵引供电系统谐振特性的影响规律。在供电方案综合评判中引入谐波谐振特性分析,研究牵引供电方案与牵引负荷谐波特性匹配问题及其对供电质量的影响。研究结果表明,牵引供电设计参数的变化对谐波谐振特性影响显著,通过优化牵引供电方案可以减少甚至避免发生谐波谐振。     

Control systems for electric drives with asynchronous traction engines

Features of the application of asynchronous three-phase engines with a short-circuit rotor for traction electric drives are discussed. Possible variants of control systems are analyzed at the structural-logic level. Recommendations of their implementation in traction electric drives of an electric-rolling stock and diesel locomotives are proven.     

A comparison of the energy efficiency of the traction electric drive of alternating-current electric locomotives based on collector and asynchronous motors

An assessment of the overall performance of 3ES5K alternating-current electric locomotives with a collector drive in the regimes of traction and recuperative braking using the concrete example of a staged route between the Khabarovsk-2 and Bikin stations of the Far East Railroad is given in this article. Real traction and brake characteristics of a 3ES5H electric locomotive in the case of a cargo train of large weight and length are shown. Analysis is carried out of all the characteristics of a 3ES5H electric locomotive, and they are compared with the movement of a 2ES5 electric locomotive with an asynchronous drive. It is determined why 3ES5K electric locomotives are more power efficient than 2ES5 ones.     

Consideration of wheel slip and readhesion control for induction traction motor electric locomotives with individual traction control

We have developed a readhesion control algorithm of the traction inverter for individual motor control locomotives. This paper describes improvements in dealing with wheel slip and readhesion control for individual‐axle electric locomotives. The major torque control is based on feedback of the difference between the basic speed of the locomotive and the individual axle speed. By combining two torque control methods, we have obtained better readhesion characteristics: little influence of dynamic axle load transfer and a high achievable coefficient of adhesion exceeding 30%. These torque control characteristics were estimated test runs and the stability limits of feedback gain are shown. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(3): 56–64, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20883     

Simulations of processes in the power circuit of VL10 (VL-10W) locomotives with traction motors connected in series

Results of simulations of the processes of changing currents and voltages in power circuits of VL10 (VL-10W) locomotives with traction motors, which are connected in series, in cold insulation have been considered. Taking the thermal state of the insulation structures of traction motors of locomotives into account is a new approach in simulations of electrical processes in power circuits. Such a differentiated approach to simulating the electrical processes in power circuits of locomotives became possible when the capacitive components of anchor and pole windings of traction motors in locomotives were studied and taken into account in the equivalent circuits, as well as their temperature dependences. In this work, the results of simulations of the processes of changing currents and voltages in power circuits of VL10 (VL-10W) locomotives during a start from rest in the case of series connection of traction motors with insulation temperature of their anchor and pole windings equal to 20°C. The results of simulations are shown as graphic time dependences of currents and voltages in the main elements of a locomotive power circuit.     

计及网压波动的牵引传动系统间谐波传播机理研究

随着多台电力机车同时投入运行后牵引供电系统出现电压波动现象,其在牵引传动系统中的传播特性是当前的研究热点.首先推导了间谐波在牵引传动系统中的传播机理,并分析了定子间谐波电流频谱与负载转矩间的对应关系;其次研究了间谐波传播下牵引电机电流间谐波辨识方法;随后基于瞬态电流控制策略、磁场定向的矢量控制策略搭建电力机车牵引传动系...     

Features of traction electric equipment of prospective electric rolling stock

On the main railways in Russia, two types of current in the contact wire are used: dc voltage of 3 kV and ac voltage of 25 kV with a frequency of 50 Hz. Therefore, prospective electric rolling stock should have double the power. Improving the capacity and structural speed of locomotives is based on the use of asynchronous traction motors (ATDs) with a squirrel-cage rotor allowing increasing the tractive force and the weight of the train and the capacity and speed of cargo delivery, increasing reliability and reducing life cycle costs, and increasing service life. Electrical equipment for such rolling stock should be used when working from either contact system, dc or ac. In this article, the scheme of power circuits is considered using the example of a module of a traction drive in one bogie of dual-system electric locomotives. It is proposed to use the secondary winding of the traction transformer as a choke of the input filter when powered from a dc contact system. Regulation of operation modes of asynchronous traction motors is carried out from static semiconductor converters with a two-tier structure. Input transducers provide the exchange of electric energy between the contact system and the intermediate link of dc voltage, and the output converters regulate the traction motors by changing the magnitude and frequency of voltage on the stator windings of ATD depending on the speed of the locomotive and its operating mode. 4QS input converters and output converters are autonomous voltage inverters of the intermediate ac: in the case of single-phase input and output, they are three-phase. The basic ratios are given to determine voltages and currents of 4QS converters, to determine the variable component of a rectified current 4QS converter, and to formulate requirements for a resonant L₂C₂ filter configured for a frequency of 100 Hz. Expressions are given for determining the ratio of the input power of the converter, as well as recommendations for determining the basic parameters of electrical equipment.     

Reducing electric-power losses in a traction network due to the voltage grading at the busbars of dc traction substations

The voltage mode in a traction network may cause unwanted power flows, which, in turn, lead to power losses in the traction network. In this paper, it is shown theoretically and on the basis of a computer simulation that the equality of voltages at the busbars of all substations ensures minimum electric-energy losses in the traction network under any changes in the parameters of the traction power-supply system and the train situation. An algorithm for controlling the voltage at the busbars of traction substations is proposed for leveling it throughout the entire section of electric dc railways.     

Using Bidirectional Converters in a Traction Drive

Russian Electrical Engineering - Modern means of power electronics are promoting a transition from standard locomotives with diesel motors and electric locomotives to traction drives with...     

Improvement of basic requirements for the system and devices of traction dc power supply

Abstract—“The Technical Maintenance Regulations of Russian Federation Railways” and “The Arrangement Regulations of the Russian Federation Railways Traction Power Supply System (TsE-462)” set out clear requirements to ensure minimum voltage in the aerial contact wire for freight and high-speed passenger train movement. These requirements are confirmed by the Norms of the European Electrotechnical Standard EN 50163 (1995). However, the voltage norms at traction substations (TsE-462) are in contradiction to the maximum continuous voltage in the aerial contact wire demanded by Railway Research Institute (VNIIZhT) and accepted by EN 50163 Standard. This paper proposes using continuous voltage at traction substations in the normal operating mode in the range of from 3600 (the minimum value) to 3700 V. The maximum voltage (3700 V) was obtained as a result of electrical calculation of the traction power supply system at the track sections with hard mountainous track profile while running trains with an increased weight of 6300–9000 t or two combined trains with a combined weight of 12000 t with powerful electric locomotives of 2ES6, 2ES10, and 3ES10 series. This voltage value was confirmed by long-term operation on a Tyumen–Yekaterinburg–Perm–Balezino track section of 923-km length with voltage stabilization at the level of 3650 V at the traction substations. The voltage levels at the traction substation buses are provided by a contactless automatic control system (CACS) with ±0.6% inaccuracy. The maximum voltage in the traction substation buses is acceptable and equal to maximum aerial contact wire voltage (4000 V) under the recuperation mode.     

电铁牵引供电系统的谐波仿真模型分析

在分析了现有牵引供电系统仿真研究的基础上,利用PSCAD/EMTDC仿真软件对电铁牵引系统进行建模,该模型由牵引变压器、电力机车、谐波检测系统构成。同时利用FFT谐波检测方法对所建模型进行测量,包括谐波总畸变率、谐波含有率。通过理论与仿真结果比较分析,验证了其正确性,且能够满足牵引供电系统的电气分析要求。     

基于SHEPWM调制的电力机车全速度运行策略及切换方法研究

电力机车功率大、直流侧电压高、开关频率低、运行速度快,针对牵引状态下电机电流谐波含量大、转矩脉动大、定子发热等问题,研究了电力机车在整个运行速度范围内的调制策略。提出了电力机车调制方式由异步调制切换至同步SHEPWM调制然后再到最大电压利用区(方波调制)的策略。理论上分析推导了减小切换电流畸变的方案,针对该策略和方案进行了仿真研究并在异步电机小功率实验平台上进行了实验验证。仿真和实验结果表明,所提出的调制策略可以作为电力机车全速度范围调制策略,切换方案能够减小电流谐波含量,提高电压利用率,使电力机车在全速度范围内平稳运行。     

Electric railway traction in Europe

This paper presents a survey of the state-of-the-art and innovational trends of electric railway technology in Europe. Subjects discussed include power supply systems, motor drive concepts, locomotives, power convertors and vehicle bus systems     

Increasing the power efficiency of a 25-kV alternating current traction power supply system

One promising method of increasing the power efficiency of an electrified railway is reducing the power capacity of the transfer process and the consumption of the electric power to the train traction. A 25-kV ac traction power supply a system features the drastically variable one-phase train load, which leads to a change in voltage on substations buses and train current collectors, as well as an increase in loss powers. The rules of the composition of the traction power supply for the fulfillment of the train schedule normalize the voltage on the substation buses and train current collector of no more than 29 kV and no less than 21 kV. Analysis of operation of the traction power supply system is carried out, and steps are taken to increase the engineering and economic performance of 25-kV ac railways. A new notion of normal power supply circuits of traction loads synthesized on the basis of simulation is presented. Analyzing the structure of the imbalance of electric power and voltage in traction network allows one to define steps toward increasing power efficiency. The accuracy of the initial data is determined by comparing the expected and real train schedules, as well as electric load curves. The simulation accuracy is determined on the basis of predictable power and voltage losses with monitoring results.     

基于信息融合技术的AT牵引网故障测距方法的研究及其仿真分析

牵引供电系统是电气化铁路的基础,牵引供电系统由于受到机车运行的工况变化的影响,以及一些不确定的因素,容易出现接地故障,又由于牵引供电系统不同于高压输电线路,所以牵引网的故障测距有着自身的特点。根据AT牵引网的实际电路在PSCAD中构造带机车负荷的仿真模型,对机车在牵引网上运行时的电压电流变化进行模拟,得出牵引网在发生短路情况下的故障数据,再利用MATLAB对仿真得到的数据进行阻抗法和行波法测距,比较两者的优缺点,最终提出将二者结合实现信息融合测距。     

Improving the energy performance of alternating-current electric vehicles

Russian Railways has taken an active position on the implementation of programs aimed at energy saving. The strategic priority of these programs is the development and introduction of new types of energy-efficient rolling stock, as well as modernization of existing and procurement of new locomotives with improved energy characteristics. After a long period of stagnation in the transport-engineering industry, railway- equipment manufacturers have started to use advanced resource-saving technologies. However, ac electric locomotives with rectifier–inverter converters and electrical locomotives with diode rectifiers equipped with a step-voltage regulator for the traction transformer are still used by Russian Railways. Despite the fact that starting and speed control of ac electric locomotives are carried out without losses in starting resistances, the increased consumption of reactive power and distortion of the form of current consumed from catenary system are a common problem for electric locomotives of this generation. The main methods and circuit design of reactive power regulators and selectors of current high harmonics and voltage in ac electric rolling stock, as well as the principle of operation and structure of the active and hybrid filters and power correctors, are considered in this article. Examples of various technical solutions providing active filtration of higher harmonics are given.     

电力机车变压器和应涌流产生机理与影响因素

为研究电气化铁道电力机车变压器和应涌流产生机理,建立了牵引供电系统、合闸电力机车以及运行电力机车的数学模型,利用Laplace变换求解出机车变压器磁链的解析解。通过搭建车网仿真平台分析了合闸变压器和运行变压器的磁链变化过程以及多种条件下和应涌流的变化规律,得到了影响和应涌流变化的关键因素,并分析了励磁涌流以及和应涌流对牵引网电压的影响。分析结果表明了合闸电力机车的励磁涌流会造成运行电力机车出现和应涌流现象,并造成牵引网电压发生严重跌落和畸变,为车网系统出现的异常跳闸现象提供参考。     

电力机车PMSM自适应模糊滑模控制

为研究牵引工况下电力机车永磁同步电机(PMSM)的转速控制精度,考虑轮轨接触不平顺及车体静载荷在轮对径向产生的未知时变负载转矩,建立了机车PMSM在d-q坐标系下的数学模型。针对该耦合非线性系统中存在的负载转矩,设计非线性转矩观测器对其实际值进行估计,对观测误差采用自适应模糊逻辑系统进行逼近;为考察d轴电压过零跳变对转速控制及转矩观测性能的影响,在d轴电压控制器设计中引入Nussbaum函数,并依据Lyapunov稳定性理论,构造了基于转矩观测器的自适应模糊滑模控制器。理论分析及仿真结果表明,当转矩时变或d轴电压过零时,机车PMSM闭环转速控制系统跟踪误差一致有界,转矩观测误差收敛于0。     

电气化铁路牵引变电所概率谐波电流的仿真计算

推导了多辆电力机车运行条件下电气化铁道牵引变电所谐波电流计算公式，考虑了电气化铁道操纵规程对谐波的影响，设计了相应的数据库存放牵引负荷谐波仿真计算所需要的信息。文中所开发的仿真软件能够依据铁路部门的运行图和操纵图，结合电力机车谐波电流动态仿真计算模型，考虑牵引负荷主要的随机因素，利用蒙特卡罗法得到牵引变电所高压母线全天24 h谐波电流的概率分布和统计特性。     

交-直-交电力机车接入的牵引供电系统电压波动特性

针对交-直-交电力机车接入牵引供电系统引发电压不稳、机车牵引封锁的现象,通过理论推导证明了该现象并非低频振荡而是电能质量问题。采用调制理论分析了低频调制信号在整流器中传播产生对称频率成分的机理;使用离散傅里叶变换分析了电压的不稳定特性,并采用总体最小二乘法-旋转不变技术的信号参数估计(TLS-ESPRIT)算法对其主导模态进行辨识,在此基础上将该现象定位为电压波动问题;利用不稳定电压的数学描述对信号重构,通过分析重构信号的多种性能评价指标进一步验证分析的合理性。