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The article focuses on the problem of energy intensity in rail vehicles and analyzes current technologies aimed at reducing it. The author discusses innovations and strategies aimed at increasing energy efficiency in rail transportation. He also outlines the challenges of reducing energy consumption in this sector and future development prospects. The main focus of the article is on the problem of energy demand in rail vehicles, with a special emphasis on railroads. The author analyzes the current challenges of high energy consumption in rail transportation and presents various technologies that have been introduced to minimize this consumption. The article includes descriptions of technological innovations such as advanced energy management systems, efficient braking systems that recover energy, and the use of low aerodynamic drag materials. The author also discusses strategies to improve the energy efficiency of rail vehicles, including both existing ones and those planned for market introduction. One of the key points of the article is also a presentation of the challenges of reducing energy consumption in the rail sector. These include the need to adapt existing infrastructure, the financial aspects of introducing new technologies, and acceptance by consumers and operators, among others. [ABSTRACT FROM AUTHOR]

For a selected train journey with multiple trains in the same traction power system, the given driving strategies of other trains can be abstracted as available external power flow. Aims at reducing the energy consumption of the multi‐train system, this paper presents an analytical solution for optimising the selected train trajectory to maximise the utilisation of the external power flow. Specifically, a spatial‐temporal area which combine the track grade along space and the external power over time is constructed and the problem is converted into the energy‐efficient control of a train travels in the spatial‐temporal area. Classical methods of constrained optimisation is used to show that the set of the optimal control modes and the optimal driving speed for the proposed problem are in a state of change. In order to obtain the optimal driving strategy, the spatial‐temporal area is divided into grids, and the evolution of a key adjoint variable when the external power changes is discussed. The authors illustrate our results by finding optimal control sequences and associated speed profile for the freight train in some elementary but realistic examples. [ABSTRACT FROM AUTHOR]

The rapid increases in the quantity of data being gathered regarding technological systems such as railways can promote improvements in their design and operation. Combining information from different datasets allows more in-depth analysis, such as using train location data to enhance the analysis of speed profiles and energy consumption. Positioning systems such as GPS are frequently used to obtain this information, but are not necessarily always available, such as in underground metro systems. The focus of this paper is therefore the development of algorithms to derive train location information from measured speed profile data and network topology. Two different algorithms were developed to extract individual station-to-station journeys from an example consisting of a dataset of speed profiles and energy consumption from an urban rail system, and four classification algorithms were developed to identify the station pairs associated with each journey. It was found that the best-performing approach for this task was to compare the cumulative distance of a group of several consecutive journeys against a database of station-to-station distances to find the best match. This was more resilient than constructing sequences of consecutive journeys from possible matches in a database of station-to-station distances and orders of magnitude faster than heuristic algorithms. [ABSTRACT FROM AUTHOR]

Abstract The performance improvement is closely related to the energy-saving operation of urban rail transit system and the improvement of service quality, which involves the optimization of infrastructures, the application of advanced train control technology, the highly efficient transportation organization, and the recycle and utilization of regenerative energy, etc. With the energy consumption as an entry, we first discuss the performance of urban rail transit system, determinate the corresponding performance evaluation indexes, and establish the top-down decomposition architecture of global performance. Then, we analyze the performance emergence mechanism of urban rail transit system, and build the difference equations of calculating train behavior in the constant power and natural characteristic regions and the mathematical model of train behavior optimization. The simulations are used to analyze the influence of train light-weighting, train control, and the load ratio on the energy efficiency of train operation, which can help to improve the system performance. Finally, we discuss the recycle and utilization of regenerative energy generated from train braking, the energy-saving operation of the environment control systems, and the optimization of train stop scheme, etc. The research shows that the potential of improving the performance of urban rail transit system is enormous, and deserves more attention. [ABSTRACT FROM AUTHOR]

Highlights • Review the literature of railway efficient railway operations from a data driven perspective. • Identify issues in current data and models related to data volume variety and validity. • Derive a roadmap for data driven applications in energy efficient railway operations. Abstract Railway systems must increase their performance and economic competitiveness to remain an effective and efficient transport mode. Energy efficiency goals are one of the main drivers for the future evolution of planning and operations of transport systems. An opportunity to improve energy efficiency together with reliability and feasibility of railway systems come from the huge amount of data being currently collected and available in the future. The hidden potential in large sets of data for improving energy efficiency can be fully exploited through novel, data-driven approaches. This paper discusses the relation of those future approaches with the current state of the art and challenges, highlighting natural advantages and possible weak points. We identify dimensions within the current literature describing the suitability of current approaches to embrace the data revolution, and the possible enhancements resulting from that. We refer to practical test cases based on real on-board monitoring of electric trains in Switzerland to identify current and future challenges in improving energy efficiency of train operations. We conclude with a discussion and a roadmap on the introduction of data-driven approaches for improving energy efficiency of railway systems. [ABSTRACT FROM AUTHOR]

Essential imbalance and fluctuation of the mobile train load draw some problems, e.g., three-phase unbalance, reactive power, voltage and load fluctuation, harmonics, etc. in both public and train supply networks (TSNs). Railway power flow controller (RPFC)'s good performance on dealing with those problems has been convinced in practice these years. However, as the primary task in commercialization, how to qualitatively determine RPFC's design capacity with high cost efficiency and how to comprehensively assess its performance in the design stage have perplexed engineers for many years. To solve those problems in both planning and real-time executing processes, this paper focuses on an RPFC design capacity optimization strategy for grid-connection compatibility and operating performance improvement in terms of both the utility and the TSN. The strategy not only makes a railway substation satisfy the grid-connection standards with high calculating efficiency, but also renders the RPFC to have the minimum design capacity, the excellent feeder voltage control ability, the good fixed capacitor installing prospect, and the high operating efficiency on the targets of reducing the investment and enhancing the transportation ability. The generic models, the industry-oriented design and the quantitative analysis, discussed in this paper give an insight for those concerned based on a balance transformer. Future RPFC projects on serviced railway power systems will benefit from the proposed methodology. [ABSTRACT FROM PUBLISHER]

The installation of a stationary supercapacitor energy storage system in urban railway systems effectively improves the energy saving rate by means of recycling the train's regenerative braking energy. In this paper, a hierarchical control strategy, which consists of an energy management layer and a converter control layer, is proposed. In the energy management layer, the energy management state machine is introduced. In the converter control layer, based on the double closed-loop proportional-integral (PI) control strategy, a multiobjective optimization algorithm for the outer voltage loop is proposed, which optimizes the control parameters at each operating point, comprehensively considering undershoot suppression, rapidity, and antidisturbance performance of the system. The proposed control strategy is validated through simulation and laboratory experiment, and finally, applied in the Megawatt-level energy storage device of Beijing Batong Line. [ABSTRACT FROM PUBLISHER]

When two trains travel along the same track in the same direction it is a common safety requirement with three-aspect signalling that the trains must be separated by at least two signals if they wish to continue following the planned schedule. Under these separation conditions there will always be at least one clear section of track between the two trains. When these conditions are violated the following train must adopt a revised strategy that will enable it to stop at the next signal if required. In this paper we find necessary conditions on non-level track to minimize the total tractive energy required for both trains to complete their respective journeys within the allowed time subject to safety-compatible separation constraints in the form of a prescribed set of latest allowed section exit times for the leading train and a corresponding prescribed set of earliest allowed section entry times for the following train. We use classical methods of constrained optimzation to show that the optimal driving strategy for each train is defined by a unique optimal driving speed on each section and that the sequence of optimal driving speeds is a decreasing sequence for the leading train and an increasing sequence for the following train. We illustrate our results by finding optimal strategies and associated speed profiles for both the leading train and the following train in some elementary but realistic examples. [ABSTRACT FROM AUTHOR]

This paper presents the design, modeling, lab test and field demonstration of a railroad energy harvester featuring rapid anchorless mounting. By harvesting energy from rail track deflections, the proposed system can be used as an alternative energy source along the trackside of railroads. Compared to the widely electrified passenger rails, most freight rails are still lack of cost-effective access of electricity because of the long haul and remoteness of the geographic location. This paper aims to address two challenges: increase power capacity and ease of installation. A spring preload and reset mechanism is used to eliminate the need of anchoring the harvester into the railroad foundation, allowing the harvester to be installed rapidly without affecting the track substructures. A dynamic model including the AC generator, the mechanical motion rectifier, and the spring preload is created and the design parameters are obtained from numerical simulations. Lab and in-field tests are carried out to verify the model and simulation. In-field test results show 7 W (average)-56 W (peak) electrical power are generated with a freight train traveling at 64 km/h (40 mph) under 5.7 mm deflections. The proposed harvester has the potential to support many track-side electrical devices and serves as an alternative energy source to enhance rail operational safety. [ABSTRACT FROM AUTHOR]

One of the most important aspects of the design activity of passenger railway vehicles is the optimization of the comfort level that is often in contrast with other requirements, such as low weight, to reduce energy consumption, and high and flexible seating capacity. Due to the coach weight reduction, the car body structure becomes more susceptible to structural vibrations that affect the passenger comfort. In modern vehicles, seats are important elements to achieve the desired comfort, but in order to design and estimate the actual comfort level, the whole system must be considered, including the track excitations, a vehicle detailed dynamic model, and the coach and the seat flexibility. This paper describes a numerical model of a double-deck vehicle developed using a MB code that considers measured track irregularities, a detailed vehicle model, and a transfer function of the seat obtained by experimental tests on an optimized seat. In order to make the numerical model more realistic, the coach has been modeled as a flexible body to consider the effect of its natural frequencies. The work has been performed within the “CARITAS” project, whose aim is the design of a high comfort vehicle for people with reduced mobility. [ABSTRACT FROM AUTHOR]

SUMMARY 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. [ABSTRACT FROM AUTHOR]

Driver advisory systems, instructing the driver how to control the train in an energy efficient manner, is one the main tools for minimizing energy consumption in the railway sector. There are many driver advisory systems already available in the market, together with significant literature on the mathematical formulation of the problem. However, much less is published on the development of such mathematical formulations, their implementation in real systems, and on the empirical data from their deployment. Moreover, nearly all the designed driver advisory systems are designed as an additional hardware to be added in drivers’ cabin. This paper discusses the design of a mathematical formulation and optimization approach for such a system, together with its implementation into an Android-based prototype, the results from on-board practical experiments, and experiences from the implementation. The system is based on a more realistic train model where energy calculations take into account dynamic losses in different components of the propulsion system, contrary to previous approaches. The experimental evaluation shows a significant increase in accuracy, as compared to a previous approach. Tests on a double-track section of the Mälaren line in Sweden demonstrates a significant potential for energy saving. [ABSTRACT FROM AUTHOR]

This paper presents the training of an artificial neural network using consumption data measured in the metropolitan network of Valencia, Spain, to estimate the energy consumption of a metro system. After calibration and validation of the neural network, the results obtained show that it can be used to predict energy consumption with high accuracy. Once fully trained, the neural network is used for testing hypothetical operational scenarios aimed to reduce the energy consumption of a metro system. These operational scenarios include different vertical alignments that prove that Symmetric Vertical Sinusoid Alignments (SVSA) can reduce energy consumption by 18.41% in contrast to a flat (0% gradient) alignment. [ABSTRACT FROM AUTHOR]

Energy consumption for multiple trains on the urban subway line is predominantly affected by the operation strategy. This paper proposed an energy-saving operation strategy for multiple trains, which is suitable for various line conditions and complex train schedules. The model and operation modes of the strategy are illustrated in detail, aiming to take full use of regenerative braking energy in complex multi-train systems with different departure intervals and dwell times. The computing method is proposed by means of the heuristic algorithm to obtain the optimum operation curve for each train. The simulation result based on a real urban subway line is provided to verify the correctness and effectiveness of the proposed energy-saving operation strategy. [ABSTRACT FROM AUTHOR]

A methodology to design energy-efficient timetables in Rapid Railway Transit Networks is presented. Using an empirical description of the train energy consumption as a function of running times, the timetable design problem is modelled as a Mixed Integer Non-Linear optimization problem (MINLP) for a complete two-way line. In doing so, all the services in both directions along a certain planning horizon are considered while attending a known passengers’ demand. The MINLP formulation, which depends on train loads, is fully linearised supposing train loads are fixed. A sequential Mixed Integer Linear solving procedure is then used to solve the timetabling optimization problem with unknown train loads. The proposed methodology emphasizes the need of considering all the services running during the planning horizon when designing energy-efficient timetables, as consequence of the relationship among train speeds, frequency and fleet size of each line. Moreover, the convenience of considering the energy consumption as part of a broad objective function that includes other relevant costs is pointed out. Otherwise, passengers and operators could face up to an increase in the whole cost and a decrease in the quality of service. A real data scenario, based on the C-2 Line of the Madrid Metropolitan Railways, is used to illustrate the proposed methodology and to discuss the differences between the energy-efficient solutions and those obtained when considering operation and acquisition costs. [ABSTRACT FROM AUTHOR]

Energy-efficient train operation is of high importance in urban railways. It takes into account both energy saving and punctuality at the same time, which is the goal of the most operators. In this study, the effect of employing variable regenerative energy recovery rate (RERR) for each inter-station was shown in energy-efficient operation improvement. For this purpose, a two-stage optimisation was proposed. In the first stage, which is a mechanical optimisation, optimal speed profiles for a single train were determined by a bi-objective optimisation through a non-dominated sorting algorithm. In this stage, a simulation model for determination of train's performance was developed and utilised. It was shown that variable RERRs eventually led to different energy-time Pareto fronts. In the second stage, the total input energy for a multi-train system was minimised by using obtained optimal speed profiles from the first stage and distributing total travelling time among inter-stations (electrical/electromechanical optimisation). It was shown that optimisation of the net energy - with different values of RERR - instead of consumed energy, can reduce the total input energy of the network. The simulation results, which are based on actual operating data of Mashhad urban railway system, confirm the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

With the energy consumption rising in rail transport, the railway sector is showing increasing interest in the energy-efficient operation of freight trains. Freight trains require more complicated driving strategies than ordinary passenger trains do due to their heavy loads, especially in the long-distance steep downhill (LDSD) sections that are very common in freight rail lines in China. This paper studies the energy-efficient operation of a freight train considering LDSD sections. An optimal control model including regenerative and pneumatic braking is developed for the freight train. Then, when a train leaves/enters the LDSD section, we verify the uniqueness of control transitions and discuss the speed profile linkage between LDSD and its adjacent sections, which indicates that the periodic braking should be applied on LDSD sections for optimality. Additionally, given the same running time for the entire journey, our analysis shows that electrical braking-full braking strategy is more energy-efficient than coasting-full braking strategy on LDSD sections. Finally, a numerical algorithm for the optimal driving solution is proposed. The simulation results demonstrate that the driving strategies generated by the proposed algorithm performs better than those from fuzzy predictive control and field operation regarding energy saving. [ABSTRACT FROM AUTHOR]

Nowadays when the climate change represents real challenge for the world to try to ensure an environmentally more sustainable future and the researchers are looking for renewable energy sources, green engineering solutions, environmentally friendly systems to reduce the air and noise pollution, the energy consumption, the railway system represents many possibilities in this subject. For the proper operation of the railway systems, it is essential providing of suitable infrastructure and good maintenance work. In this article the authors are analyzing the optimization possibilities of railway sleepers depending on the type and quality of ballasted layer. The aim of these optimization processes are to increase the serviceability life-span of the sleepers with efficient technological process, changing the support conditions according to local circumstances. [ABSTRACT FROM AUTHOR]

The length of metro lines with driverless train operation (DTO) systems is increasing globally and is predicted to triple in the next 10 years. This paper gives the history and future trend of the DTO systems. The opportunities provided by the DTO systems, such as lower operation costs, increased capacity, and energy efficiency, are explained and the relevant research are reviewed. Furthermore, the challenges faced by the DTO systems are analyzed, such as safety issues, train control technology, and emergency situations. [ABSTRACT FROM AUTHOR]

Many solutions have been developed to reduce energy consumption in rail, covering the three main areas of rolling stock, infrastructure and operations. These solutions often show significant energy savings in theory, simulation and practice. However, the success of a solution can only be evaluated within the scope of the study performed, which is limited to specific case studies. Because railways vary greatly, a solution deemed effective when applied to one railway may not be well suited to another, due to inherent differences. This work therefore aims to develop a method to evaluate solutions for complex systems, using energy saving in rail as an example. Distinct subsystems are quantitatively defined by determining the factors that make them unique. For rail, these are categorised into route, vehicle and service characteristics. Next, key performance indicators are identified that relate to the success of solutions. Finally, a sensitivity analysis is performed to evaluate which factors influence solution success for each subsystem. In-depth simulations of solutions can then be completed. The developed method is used to find the most influential factors when considering energy-saving solutions applicable to single trains, for six types of railway subsystems, using Morris' elementary effects method of sensitivity analysis. [ABSTRACT FROM AUTHOR]

When considering the energy consumption and associated greenhouse gas emissions of a railway, it is important to account for both operational aspects (primarily running of the trains) and non-operational aspects, including energy and emissions embedded in infrastructure. The latter are heavily dependent on civil engineering structures such as tunnels, bridges and viaducts, as well as earthworks needed to provide route alignment. In some cases this can lead to a conflict between infrastructure design that has operational benefits and that which reduces embedded impact. This paper introduces the idea that there might be trade-offs between embedded and operational energy and emissions. A mixture of empirical and simulation data is used, and tunnels are used as a specific case study. The results are discussed in the context of wider sustainability issues. [ABSTRACT FROM AUTHOR]

In CBTC (Communications-Based Train Control) operated metro lines, headway can be reduced by taking advantage of the system's train–track continuous communication, thus increasing transport capacity. When a train runs close enough to the preceding one, a tracking algorithm is triggered to control the distance between the trains. The following train receives the LMA (limit of movement authority) via radio, which is updated periodically as the preceding train runs. Besides transport capacity, one of railway operators’ main goals is the reduction of energy consumption, for environmental and economic reasons. This paper firstly shows that the existing basic CBTC tracking algorithm is not energy efficient, due to the application of short braking–traction cycles. It then proposes a new efficient algorithm that makes use of coast (null traction) command, and models the uncertainty associated with the speed of the preceding train. This fuzzy algorithm is compared to the basic one in terms of energy consumption, running time and steady state interval (resulting tracking interval). Simulation results show that the proposed fuzzy tracking algorithm provides important energy savings with minor influence on running time and steady state interval. This algorithm is suitable for implementation in on-board CBTC equipment to reduce the energy consumption of traffic operation. [ABSTRACT FROM AUTHOR]

As the demand for alternative sources of energy has increased, harvesting abundant environmental energy such as vibration energy including track vibrations in railway systems has attracted greater attention. In this study, we develop a portable high-efficiency electromagnetic energy harvesting system with supercapacitors that converts the energy of track vibrations into electricity. The generated electricity is stored in the supercapacitors and used in remote areas for safety facilities or in standby power supplies for rail-side equipment. The proposed system consists of a mechanical transmission and a regulating circuit. Acting as the energy input and transmission, Gears and a rack amplify the small vibrations of the track, and one-way bearings enhance efficiency by transforming bidirectional motion to unidirectional rotation. Supercapacitors are used in the vibration energy harvesting system for the first time. The supercapacitors permit the storage of energy from rapidly changing transient currents and a steady power supply for external loads. The proposed system is demonstrated through dynamic simulations, which show the rapid response of the system. An efficiency of 55.5% is demonstrated in bench tests, verifying that the proposed electromagnetic energy harvesting system is effective and practical in renewable energy applications for railroads. [ABSTRACT FROM AUTHOR]

To become more competitive, railways are developing methods and technologies that enable cost reduction, higher capacity, better punctuality and greater sustainability. The authors of this study address the last two objectives and propose a method that can be used to minimise the impact of a single delay on the system by reducing both the deviation from timetabled arrival at timing points and the energy consumed by trains. The technique uses a combined macro- and microscopic level approach in an optimisation algorithm to calculate the maximum speed a train should travel at on different sections of its route, so that the train meets time constraints and saves energy. The algorithm interacts with the traffic management system to obtain the applicable time constraints. The initial results from a case study based on a single-track railway line show that applying this method to a freight train that needs to pass a late running passenger train at a loop and to arrive on time at its last station allows a 9% reduction in energy use by comparison with a situation where the freight train trajectory is not adjusted as a function of the actual traffic conditions. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of a three-phase dual active bridge (DAB) topology used as high-power-density dc–dc converter for railway applications. The three-phase DAB is analyzed concerning the current intervals, the output power, and soft-switching region, including the impact of zero-voltage switching capacitors. Furthermore, two measures are proposed to achieve soft-switching in the entire operating range, being auxiliary inductors and a straightforward switching strategy called the burst mode. Optimal component values are calculated to minimize losses in the complete operating range and to assess which measure is best suited. A prototype with the specifications acquired from the application has been built, yielding an efficiency of $95.6\%$ at a nominal output power of 80\, {\rm kW}. [ABSTRACT FROM AUTHOR]

Subway systems consume a large amount of energy each year. How to reduce the energy consumption of subway systems has already become an issue of concern in recent years. This paper proposes an energy-efficient approach to reduce the traction energy by optimizing the train operation for multiple interstations. Both the trip time and driving strategy are considered in the proposed optimization approach. Firstly, a bi-level programming model of multiple interstations is developed for the energy-efficient train operation problem, which is then converted into an integrated model to calculate the driving strategy for multiple interstations. Additionally, the multi-population genetic algorithm (MPGA) is used to solve the problem, followed by calculating the energy-efficient trip times. Finally, the paper presents some examples based on the operation data of the Beijing Changping subway line. The simulation results show that the proposed approach presents a better energy-efficient performance than that with only optimizing the driving strategy for a single interstation. [ABSTRACT FROM AUTHOR]

Hybridisation of diesel-driven rail vehicles is already possible and promises significant reductions in fuel consumption and exhaust emissions (nitrogen oxides and particulate matter). However, current performance can be significantly improved by introducing technologies such as energy storage systems. The aim of this paper is to investigate the energy management strategies and technical life cycle cost aspects of railway-specific hybridisation architectures. To do so, twelve promising combinations of system architectures, energy storage systems and railway duty cycles have been selected, described and analyzed. A method based on a MATLAB/SIMULINK model has been used with three different approaches for the energy management strategy optimization (i) the Covariance Matrix Adaptation Evolution Strategy as baseline optimization; (ii) dynamic programming to determine the global optimum and (iii) a sensitivity analysis approach for the energy storage systems. Based on these boundary conditions, a hybridisation life cycle cost analysis has been carried out. As part of this analysis three different fuel price scenarios have been considered (i) low price of 0.78 €/l; (ii) medium price of 1.12 €/l; (iii) high price of 1.64 €/l. The results show that different energy storage technologies achieve diverse life cycle costs, triggering a range of investment, replacement and maintenance costs, as well as significantly reduced operational costs due to lower fuel consumption. In addition, the simulation results show that fuel consumption can be reduced up to 20%, in some cases rising to approximately 25% if energy management strategies are applied. Of these, Start/Stop and downsizing of the internal combustion engine are the most promising strategies for the emission reduction. Both require auxiliaries’ electrification and appropriate integration of energy storage systems. LCC results also indicate that operational conditions with high annual mileage are most beneficial when a hybrid consisting of an internal combustion engine and an energy storage system is used in a high fuel price scenario. [ABSTRACT FROM AUTHOR]

The Locomotive Assignment Problem (LAP) is a class of planning and scheduling problems solved by assigning a fleet of locomotives to a network of trains. In the planning versions of the LAP, the type of consist (a group of linked locomotives) assigned to each train in a given schedule is determined. We introduce an optimization model (called consists selection) that precedes the planning LAP solution and determines the set of consist types. This selection leads to solutions that are characterized by potential savings in terms of overall fueling cost and are easier to handle in the routing phase. [ABSTRACT FROM AUTHOR]

Rail transport through the use of electric traction is more friendly for environment than other means of transport. It has a lot of benefits, mainly: the possibility of mass transport using as little energy as possible per one passenger, reducing crowd, reducing congestion, lower emission of pollution, weatherproof, more safety, regularity of travelling. As we can see from the above mentioned benefits, public tram transport is one of the most popular means in Poland. Tram market in Poland is one of the largest in the world. Nowadays we have 14 thousand tram lines used by 16 companies, which gives a total of above 3600 cars. We have many types of trams exploited at present. The most popular are cars 105Na, characterized by low comfort for passengers, too low durability and high energy consumption. Because these cars are at present exploited, on the basis of their structure many different modernizations are made. The examples could be two types of cars : 204WrAs and 205WrAs, which have been produced since 2005 by the Wrocław PROTRAM Company. The largest Polish cities also use a modern trams stock produced by the largest Polish construction companies. One of the examples is recently using five-cars type 120Na produced by PESA company. This article presents results of measurements of energy consumptions of trams 105Na using traditional start --up resistance and trams PROTRAM 205WrAs type with asynchronous propulsion system in IGTB technology. Then the energy consumption is compared with data obtained from manufacturer of a modern tram PESA 120Na, working in the same conditions -- asynchronous propulsion system. [ABSTRACT FROM AUTHOR]

In the railway sector, one of the sensitive issues to be borne very much in mind is the cost brought about by the energy consumption required to meet schedules, be they local trains, metropolitan systems, or long-distance trains. To reduce energy consumption, considering restrictions like traveling time or speed limits, it is necessary to find a solution for a complex problem in the domain of optimal control theory (OCT). The analytical solution for those problems is not easily carried out. A simpler alternative to that approach is presented in this paper, using a semianalytical solution that leads to a discretization and to the application of the Langrage multipliers method to solve the optimization of n-tuples of speed. With the solution introduced in this work, is possible to include all the details about train operation, such as timetable restrictions or braking types. In the full paper, the detailed solution is presented as well as some real cases to illustrate the method results. [ABSTRACT FROM AUTHOR]

Thereal-time traffic control has an important impact on the efficiency of the energy utilization in themodern railway network. This study is aimed to develop an energy-efficient railway traffic control solution for any specified railway. In otherwords, it is expected to define suitable driving profiles for all the trains running within a specified period through the targeted network with an objective to minimize their total energy consumption. How to optimize the train synchronization so as to benefit from the energy regenerated by electronic braking is also considered in this study. A method based on genetic algorithm and empirical single train driving strategies is developed for this objective. Six monomode strategies and one multimode strategy are tested and compared with the four scenarios extracted from the Belgian railway system. The results obtained by simulation show that the multi-mode control strategy overcomes the mono-mode control strategies with regard to global energy consumption, while there is no firm relation between the utilization rate of energy regenerated by dynamic braking operations and the reduction of total energy consumption. [ABSTRACT FROM AUTHOR]

Based on simulations of passenger transports of two representative types of metro trains in China, this study analyzes efficiencies of energy consumption and passenger transport of a metro train in the effect of its target speed, formation scale (FS) (i.e., length and mass of the formation), relative traction capacity (RTC) (i.e., ratio of the motoring cars to all its cars), and so forth. It is found that increasing energy cost efficiency of ametro train with decreasing its target speed is evidently accelerated with reducing its RTC below 0.50 at the expense of obviously lowering its passenger transport efficiency. Moreover, if the passenger capacity of the train is sufficiently utilized, increasing its FS for the same RTC is easy to have its passenger transport efficiency improved significantly even for a meanwhile much decreased target speed with consuming energy less intensively. Therefore, metro trains in peak hours may take comparatively big FSs, relatively high target speeds, and RTCs over 0.50 tomeet usually urgent and large-scale travel demands in such time. In contrast, trains in nonpeak hours ought to have small FSs, relatively low target speeds, and RTCs smaller than 0.50 for mainly avoiding energy waste. [ABSTRACT FROM AUTHOR]

A new inductive power transfer system with a narrow rail width, a small pickup size, and a large air gap for online electric vehicles is proposed in this paper. By introducing a new core structure, the orientation of the magnetic flux alternates along with the road; hence, an inductive power transfer system with a narrow rail width of 10 cm, a large air gap of 20 cm, and a large lateral displacement about 24 cm was implemented. The resonant circuit of the inductive power transfer system, driven by a current source, was fully characterized. The experimental results showed that the maximum output power was 35 kW and that the maximum efficiency was 74% at 27 kW. The proposed system was found to be adequate for electric vehicles, allowing them to drive freely on specially implemented roads by obtaining power from the buried power supply rail. [ABSTRACT FROM AUTHOR]

US-based ReliOn has recently launched its newly enhanced E-200 fuel cell system, which is now being shipped to customers. This hydrogen-fueled product offers a number of features to improve customer usability, ease of maintenance, and performance. Upgrades to the E-200 fuel cell system were driven by feedback and input from existing customers, and expand the reach of this power solution into additional markets. [ABSTRACT FROM AUTHOR]