2nd UIC Railway Energy Efficiency Conference - Paris, 4-5 February 2004
Environmentally Sustainable Transport - driving the economic development? by Peter Wiederkehr, OECD
Continued growth in the number of motorised vehicles and their use places major burdens on the availability of natural resources, notably oil. Emissions from the burning of motor vehicle fuel contribute to global and local damage to ecosystems and human health.
The OECD’s project on Environmentally Sustainable Transport (EST) helps respond to these trends and make transport sustainable. Nine countries contributed to six case studies. EST was defined, envisioned, and then quantified in terms of internationally agreed standards for ecosystem and human health. Six EST criteria - for noise, land use, and emissions of carbon dioxide, nitrogen oxides, volatile organic compounds, and particulate matter - were set for the year 2030 in relation to conditions in 1990. The teams developed EST scenarios consistent with the criteria and also ’business-as-usual’ (BAU) projections for 2030. The EST scenarios involved more use of public and non-motorised forms of transport and new mobility services and less travel by cars and aircraft for passengers transport. For freight transport, the EST scenarios indicate improved supply chain management and more movement of freight by rail than by road. The assessment suggested that about half of the reduction would result from improvements in technology and half would result from changes in transport activity. The overall impacts of moving towards EST would appear to be positive: economies would remain robust, society’s costs would be lower, and there could be social advantages. The most important challenges for the attainment of EST concern well-tuned phasing of implementation strategies and their component policies and instruments as well as the involvement of stakeholders from governments, industry, non-governmental organisations and the public. Finally, an objective’s-based approach, as for the EST project, serves as a promising model for other sectors.
AAR Activities in the Area of Energy Efficiency and Air Emissions by Robert E. Fronczak, AAR (USA)
Railroads are by far the most environmentally friendly mode of surface transportation. Railroads are aggressively implementing innovative ways to save fuel by reducing locomotive idling, including the introduction of auxiliary power units that allow the main locomotive engine to be shut down. This paper will also discuss the regulations that the U.S. railroads currently have to comply with, what is on the horizon in the regulatory arena, as well as extra regulatory or voluntary activities the U.S. railroads are undertaking to reduce emissions and improve energy efficiency.
EVENT & EVENT Com Tool by Jessica Ahrens, DB AG
More than 90 technologies and measures, which can lead to better energy efficiency of rolling stock and train operation of Railways, have been described and evaluated in the EVENT-project. The compilation of data was carried out with a close contact to the European Railways and the industry. The data was evaluated by using different criteria, e.g the technological applicability of the measure on Railways, advantages, disadvantages, neccessary frame con-ditions, economic and environmental effects. Most promising technologies have been identified and recommendations for lanes of action for the UIC and the railways were derived. The results of EVENT have been published with an interactive communication tool which was created with the parallel project EVENT-ComTool. With this internet-database it is possible to search for and display specific results by using technology criteria as well as supplementing and updating the existing technologies. The results of EVENT and EVENTComTool provide the basis for the future project strategy of UIC in the field of energy efficiency and are available at the UIC-web-site www.railway-energy.org.
An introduction to Energy saving in Chinese railways by Zhengcai Jiang, China Railways
1. The history of energy saving in Chinese Railways 2. The management system of energy saving in CR 3. The regulations, policies, standards and internal rules related to energy saving in CR 4. The implementation and monitoring issues related to energy saving 5. The evolution of the traction power (stock) and the utilisation efficiency of the traction energy in CR 6. Upgrading the energy consuming technology for the general equipment 7. The main achievements that CR made: the reduction of total energy consumed by CR, while the total traffic volume increased 8. CR consumes the least amount of energy among all the modern transport modes in China 9. The problems that CR is facing in the field of energy saving and the suggestions to overcome them
Optimal design of timetables to maximise schedule reliability and minimise energy consumption, rolling stock and crew deployment by Bodhibrata Nag, South Eastern Railways, Calcutta
Timetable design affects the planning process at all levels - strategic, tactical and operational and is of major consequence in deciding the bottom line of the railways. Surprisingly however, this aspect has received scant attention, so far as improving on the manual methods used at present which only test for the feasibility and not the optimality. Research on the area of optimizing crew and rolling stock deployment for a given timetable and construction of timetables using mathematical modelling on very small scale have been reported. However, the problem of timetable design to optimize energy consumption and resource deployment and maximize schedule robustness has not been tackled so far, and this paper is a maiden effort in this direction. This paper identifies the decision variables and their relationship to the decision criteria of the timetable. Further metrics for quantification of the decision criteria are developed to enable formulation of the problem in terms of a mathematical model. Simulation, using C programs, are used to derive relationships, in instances not amenable to analytic derivations. Further, a Timed Colored Petri Net Model is used to simulate the movement of trains in order to obtain resource deployments for various combinations of buffer times, train frequencies, trip times and lie-over times to obtain a mathematical expression of resource deployment and energy consumption as a function of buffer times, train frequencies, trip times and lie-over times. Energy consumption is optimized by leveling of maximum demand by avoiding bunching of trains on sections being fed by the same traction sub-station. The timetable design problem has been formulated as a multi-objective non-linear mathematical model. Analytic Hierarchy Process (AHP) method is used for ranking of objectives, and then solved by the Global Criteria Approach (GCA) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods using GAMS/CONOPT software. A section of Indian Railways has been chosen as a test case, wherein substantial benefits by way of savings in energy consumption, rolling stock deployment and improvement in schedule reliability has been demonstrated using this method. This method is particularly applicable to large railways, wherein conventional methods suffer the handicap of huge problem sizes, which exceed tolerable limits of available computing power. This handicap has been overcome by proposing the concept of routes, which reduce the problem size without sacrificing the information and constraints involved. The method can also be used for on-line timetabling process by generating the pacing information of trains to optimize energy consumption, resource deployment, and schedule reliability.
A North American Standard for Spill-Proof Locomotive Refueling by Chris Barkan / AAR
The North American railroads have developed a standard for a reliable, spill-proof locomotive refueling system. The Locomotive Fueling Interface Standard (LFIS) is an open, non-proprietary standard that incorporates proven refueling equipment technologies adapted for use in the railroad environment. The LFIS was developed with extensive input and involvement by a multi-disciplinary task force composed of individuals from railroads’ mechanical, environmental, transportation and fuel purchasing groups, along with suppliers of refueling equipment for the railroad, aircraft, mining, military and cargo tank truck industries. Prototype equipment was initially tested at the Transportation Technology Center in Pueblo, Colorado and then underwent field-testing on seven North American railroads at nine different locations over a period of 22 months. Following successful completion of the field-testing the LFIS was adopted by the Association of American Railroads as a recommended practice. A cost-benefit analysis indicates that the reduction in energy and environmental costs that railroads are likely to accrue with adoption of the LFIS will pay for the new equipment in 1 to 3 years. The LFIS appears to be a cost-effective means for most North American railroads to prevent spillage and improve refueling performance.
Energy Efficient Driving by Heinrich Strössenreuther / DB AG
A potential of 80.000 € per day can be saved energy efficient driving. In 2001 the Deutsche Bahn AG has started the project ES. The goal has been to reduce the energy consumption of traction by 10 percent through energy efficient driving.
Meanwhile more than 14.000 train drivers were trained. Energy meters had been installed on all electrical trucks. A energy information system to control the consumption patterns of drivers was set up. Several R&D activities have been started to enhance energy efficient driving.
First results occur: The energy consumption decreased by 4% by 2003 in the long distance trains.
Mechanical transmission, energy saving potential - Experience with modern mechanical transmissions in DMUs DMUs Diesel Multiple Units by Peter Buchwald, DSB
Background: In the middle of the eighties DSB starter to investigate the possibilities of reducing the energy consumption for diesel train units without influencing the tractive effort and the comfort negatively.
Introductory investigations clearly indicated that the apparently best possibilities were to try to apply a more up-to-date transmission technology, which at that time had also had its starting point primarily for local busses. The technological possibility was a modern computer controlled automatic transmission.
On the positive side i.a. the following conditions were stated. · High efficiency (typically >95%) · Low weight · Big “dynamic area”, i.e. high attractive effort could be obtained together with high end speed · Possibilities of running the engine in “best point” · Attractive price On the negative side the following conditions were stated. · Reversing gear not mounted in a truck transmission. · Jumps in the tractive effort in connection with gear shift (comfort problem?) · Service life / maintenance costs
Beyond the above“physical” conditions there was much both internal and external “railway scepticism” concerning applying motor car components in trains in general.
Trials showed the way: A MR train unit (VT628) was equipped with an “engine module”, which on a joint frame consisted of diesel engine, (MAN2866LUE) cooling group, mechanical automatic gear (ZF Ecomat gear HP500) . The existing Voith gear (320) was temporarily modified for working as a reversing gear. After some introductory test runs, the train was put into normal service and provided, in spite of normal “prototype problems” so good experience that the automatic mechanical transmission were chosen for DSB’s new generation of intercity train units, which were primarily delivered during the period 1989-91 .
Until now DSB’s stock of IC3 train units (92 units) has in total been in service for 350 million km (350x10^6 km), primarily in the intercity traffic with normal speed of up to 180 km/h. Each DMU (trainset) has 4 diesel “power packs” (Dieselmotor+transmission) which brings a total of 1,4 billion (1,4x10^9 km) “transmission-kilometres”
The mechanical Transmission has clearly complied with the expectations.
During the period 350 million litre diesel fuel were filled in the trains, and this gives an average fuel consumption of 1 litre per km per train set. OBS! This consumption includes dieselfuel for oil-fired furnace, non-revenue kilometres, workshop running, etc.
Oil is changed on the mechanical transmission for each 75.0000 km, and the transmissions are overhauled for each 600.000 km. Unplanned repair is very infrequent and during the period until now transmission cases are only replaced on 2 (out of 400)) transmissions.
The anticipated LCC LCC Life Cycle Costs costs for mechanical transmission in a train unit (transmission + reversing gear) are met.
The costs caused by the more frequent intervals of overhaul (600.000 km) are amply paid by the saving of costs for diesel fuel, due to the higher efficiency of transmission, etc.
New trains for DSB DSB’s more than 12 years good experience with modern mechanical transmission has resulted in the fact that DSB has chosen mechanical transmission for the next generation of intercity trains for DSB (IC4). Meanwhile the technology - especially the computer technology - has provided even better possibilities of optimising efficiency of the traction system, etc.
A new 16 step mechanical transmission is applied for the IC4 train units. This transmission is controlled and optimised together with the diesel engine, resulting in the entire traction system being even more capable of working in the “best points” of the traction system.
In an IC3 train unit (train unit 38) DSB has 4 units as proto type, like the transmission type applied in the coming IC4 DMU, in service.
DMU+EMU operated together In Denmark diesel multiple units are operated together with electrical multiple units in the same train ->. DMU+EMU+EMU+DMU+EMU
Development of a “New Energy Train - hybrid type” by Fuji Takehito, EJR
In order to contribute to environmental conservation, East Japan Railway Company, which mainly operates electric multiple units (EMU), has significantly reduced energy consumption by introducing a large number of energy saving EMUs. The next step for the environment is the improvement of diesel cars. Because diesel engines are criticized to emit toxic substances and we have approximately 600 diesel cars, environmental friendliness and maintenance innovation for diesel cars has become an important issue.
Our diesel cars are categorized into two generations.
1st generation (approximately 300 cars): manufactured before 1990. Engines were replaced with a low energy consumption and low emission type.
2nd generation (approximately 250 cars): manufactured after 1990 with lightweight body and, low energy consumption and low emission engine. Because first generation diesel cars have aged over 30 years, they must be replaced with next generation cars. We developed a “new energy train (hybrid type)” as the next generation train and created a proto-type.
To develop the new energy train, we determined two concepts, “environmentally friendly” and “convert to EMU technology,” and four targets, I. Energy saving by reducing fuel consumption II. Reduction of toxic substances and noise III. Labor saving for maintenance IV. Improvement of driving performance (high acceleration and deceleration)
We adopted the series hybrid system composed of electric generator (and driving power generator), batteries, power converter, driving device, and so on. This system is aimed to utilize regenerative brakes efficiently, and to be applied to trains driven by fuel cells in the future. In the process of developing the system, we especially noticed that the type and capacity of the battery are important factors related to the cost and weight of the car. Then, we adopted a lithium ion secondary battery and determined the capacity through a simulation. The results of the simulation verified that the optimum battery capacity was nearly equal to the energy volume charged by a regenerative braking.
For the control of the hybrid system, we developed a “new energy control system.” Based on the command from the driving controller and train speed, the system controls the electric power generation to maintain the sum of kinetic energy and electrically stored energy. It enables the battery to always maintain the optimum charge volume. Through simulations using a model of our train operation, we verified the performance of the new energy control system and confirmed the reduction of energy consumption, which was estimated to be over 20% compared to the conventional diesel car.
Test runs of the new energy train with the hybrid system start from Spring 2003. This paper provides information about the train, including the result of test runs.
State of the art - Fuel cell technology for railways by Keiichiro Kondo, RTRI
In non-elecrtrified line the diesel cars are generally used, but they have the problems of noise, exhaust gas and the expensive maintenance. On the other hands, the railway system has to be improved more friendly with the environment. Therefore, We propose the Fuel Cell Vehicle that is to be alternative to the diesel cars and perform a feasibility study.
First off, we list the candidates that the Fuel cell system is applied to and reached a conclusion that Diesel Motive Units or DMUs are suitable for the target of the feasible study. Then we carry out the feasible study, from the view point of the designing of the DMU vehicle driven by the FC power supply system. The result of the study is evaluated to make the advantage of the FC train clear. In addition that, we conduct which kind of FC and how supply H2 to FC, too. Through the studies on this paper, we show the FC power supply system for railway vehicle traction is available enough to realize the environment friendly railway system in the near future even in the non-elecrtrified line.
PV Train-solar energy aboard! Use of solar energy for freight wagons by Alessandro Basili & Roberto Pagnoni, Trenitalia SpA
This presentation refers on studies and applications started by Trenitalia about new power supply system and renewable sources. The innovation consists mainly in photovoltaic technology development for railway applications, with economic and environmental advantages, mainly reduction in emissions of CO2 and lower waste production (rechargeable batteries instead of usual type). The project consists in photovoltaic panel installation by amorphous or crystal silicon -whose bendable characteristics allow to adapt them to the vehicles imperial - on 10 vehicles (5 coaches, 2 locomotives and 3 freight wagons). These panels will provide the chopper with power supply. The chopper will be expressly drawn for this use respecting rules and regulations from FS, CEI, EN technical normative. The chopper output will supply the battery that now take supply from 3 kV cc line. We are trying - by using the photovoltaic panels - to obtain a steady battery charge that could determine a longer life of them, with less waste disposal and more energy conservation. The testing activity will be carried out by a stand-alone system in the aim to acquire, save and process data, providing information about both electrical parameters and position by GPS in operating mode. Data will be used to compare new power supply with the existing one.
Efficiency potential in railway electrification - Indian perspective by B.M.. Lal, Indian Railways
With the modest beginning of electric traction on the ex-GIP Railway between Bombay VT and Kurla, at 1500 Volts DC in 1925 the Indian Railways have over the period embarked through a massive electrification programme and as of today more than 16000 route-kilometers (RKMs) stand electrified comprising of almost 25% of its total network. Indian Railways today haul nearly 60% of freight and 50% passenger traffic on its electrified routes. The objective of adoption of electric traction in India was primarily on account of requirement of higher acceleration essential for suburban rail transport, which was operationally not feasible and available on other choices of mode of traction. In 1957 when India Railways decided to adopt the 25 KV AC System on 50 HZ based on the trends in Europe and other developed countries, the adoption of electric traction for main line application found acceptance on a larger scale.
The electrification on Indian Railways was also obviously driven by strategic importance of petroleum conservation, which would result in saving in consumption of diesel oil as it would decrease not only on Indian Railways but also in road sector, as rail transport by itself is more energy efficient as compared to road transport and among the various modes of traction in Railway transport, electric traction is the most energy efficient. Only 100 RKMs of electrified section result in an annual saving of more than 4 million litres of diesel oil.
Indian Railways today consume only 1.6% of the nation’s total electric energy generation for hauling major portion of the traffic while it consumes more than 4.7% of nation’s total diesel oil for less than 40% traffic.
The whole system of electric traction from generation, transmission, distribution and use in electric traction is required to perform in such a manner that the wastage of energy is minimized to an extent and is cost effective as a whole. Indian Railways while progressing its electrification have continuously upgraded its system and have addressed many of the issues related to efficiency potential and energy conservation so far AC traction is concerned. Introduction of capacitor banks, regulating OHE Voltage, improvement in design of traction transformer and other equipments used in power supply and overhead installations are some of the major steps taken by Indian Railways in the area of Railway electrification. Nevertheless, there is a continuous endeavour on the part of Indian Railways to adopt various measures and techniques to improve efficiency and conserve energy and would like to share the same with other Railway systems.
Energy Efficiency of modern electrical traction system by Christian Laurencin, SNCF
In a first part, we want to make a general overview of SNCF traction system in term of efficiency. The power schemes of our latest electrical engines and the comparison of their main characteristics will be given. Results of consumption and efficiciency calculation in different operating cycles will be given for the traction engine and for the whole supply system (including lines and substations losses). Some comparisons with other transportation modes shall be given.
In the second part, the lack of standardization for efficiency characteristics and for evaluation of these characteristics in tenders will be underlined.
Electrical energy saving for urban and suburban guided transport system by Gérard Coquery, INRETS (France)
We propose an analysis of electrical energy consumption and power required for traction and auxiliary functions on urban and suburban guided system of transportation. These results are issued from measurements on different light railway systems : tramway, mass transit system (Metro of Paris) and suburban system (Regional express Train) which are managed respectively by RATP and SNCF. These guided urban transportation systems require power and energy strongly sequenced by the train stops at stations. Forces to move railway vehicle are very low: typical value is 10N per tonn of mass applied on axles. Aerodynamic forces are not predominant due to the limited speed in urban area. Tramway maximal speed rarely exceed 60km/h, tram train about 100km/h and regional express train about 120km/h. Typically, the mission profile between two stations on a flat geographical area can be identified by 4 running phases: vehicle acceleration at about 1ms-2 during 10 to 20 seconds, coasting without any traction current, braking at about 1ms-2 allowing kinetic energy regeneration, station stop during about 20 seconds which can be reduced down to 10 seconds for tramway. This status shows the high variation of absorbed power by an urban railway vehicle, but simultaneously we observe the relatively low energy required to move it thanks to the infrastructure characteristic and the possibilities of saving energy using the vehicle kinetic energy by an efficient regenerative braking system. These results are illustrated by the measurements realised on light train and metro electrical substations. The figure 1 shows the fluctuation along the line of the power that is absorbed by a tramway. It is easy to distinguish the typical 4 running period as already described: acceleration, coasting, braking, stop. The regenerative braking system allows to save energy which is sent back to the catenary line for the profit of the other tramway. Of course, if the electrical power supply is not designed for reversible capability, this regenerative braking is stopped when the upper voltage allowed is reached on the catenary, then energy is dissipated in resistance that have been embedded in the vehicle, generally located on the roof.
Optimised design and tuning of a hybrid powertrain including fuel cells and Energy Storage Systems by Laurent Nicod, Alstom Transport
Alstom Transport is a world leader in public transportation systems and railways vehicles. Focused on the environmental concerns, Alstom has several R&D projects dealing with the improvement of existing solutions used to produce or store energy on board. Three main domains are investigated : · Replace the Diesel engine by a fuel cell · Using Energy Storage System and/or Fuel Cells to hybrid Diesel-electric powertrains · Using Energy Storage System on catenary supplied trains in order to save energy.
Exploring those fields have led Alstom to work on : -*Modelisation and simulation of Fuel cells, supercapacitors pack, flywheels, batteries and energy strategies. -*Use design and optimization softwares in order to optimize the sizing and tuning of the powertrains and control laws in order to save energy consumption. -*Test components or sub-systems on test bench
Because of different reasons, it appears obvious that Fuel Cells (FC) have to be aided by an ESS. Using two or more electricity sources on board impose also a Energy Strategy for several reasons:
- Using one source is easy and is under control : this source has to provide in real time the power requested by the train. Using several sources needs to choose in real time how the requested power is supplied.
- technical or cost problem. On a Fuel Cell vehicle the tank capacity can be limited and a low consumption can be a key point for the success of the solution. We need then to use with parsimony the embarked fuel. Once again, the Energy Strategy has to optimize the use of fuel by a potential influence on auxiliaries of the vehicle, choice of operating range of components, etc...
Finally , the optimization approach used for energy savings offers to provide answers much more quickly and with a higher confidence on best choices made than a empirical approach to those questions : · Ratio of power between fuel cell and the ESS (hybridization ratio) · Energy strategy suitable with the sources properties, limitations and constraints· Energy storage technology suitable with the identified needs.
SimERT- Project Simulation of Energy and Running Time by Piotr Lukaszewicz, KTH (Sweden)
The aim of the SimERT project is to perform research on how the energy usage and running time of trains is affected in particular by the driving style and train characteristcs and how the driving style can be optimized in a rail network with respect to energy usage, driving time and time table. Computer models of trains and drivers are developed from full-scale measurements and thereafter verified. The driver computer models can drive a train in a similar way as an average driver would do, by making use of developed driving describing parameters. It is also possible to drive in any desired way, so that optimised style of driving can be tested with respect to energy usage and time table. The developed and verified models of trains and drivers are going to be implemented into SIMON which is a commercial traffic simulation computer program owned by the Banverket (Swedish National Rail Administration). This paper describes the SimERT project and a review of the research will be made with some conclusions.
Environmental impact calculation of transport with EcoTranIt (Ecological Transport Information Tool) by Raimondo Orsini, Trenitalia SpA
Strategic value of energy storage technology options for railways by Herman Annendyck, EPRI Worldwide
On behalf of the electricity sector (transmission & distribution companies, renewable energy companies, end users), EPRI (Electric Power Research Institute) has gathered a long and vast experience with energy storage technologies via demonstration, testing and technical-economical modeling such as to foster specific needs or incentives as there are improvement of power quality, power supply reliability (uninterruptible power supplies), converting non-dispatchable renewable plants to dispatchable ones, matching the demand side with the load side, deferring investments for expansion or extension of transmission systems, shifting renewable generated energy to the most economic portion of on-peak time periods, .... Thanks to its specific characteristics, the new ultracapacitor technology can fit in applications requiring relatively high cycle life and round-trip efficiency, wide temperature variations and fast charge/discharge response. In this application niche, ultracapacitors and flywheels behave very similiar whereas ultracapacitors could become the most practical in the long run because they are less complex and provide more kWh storage per unit weight. Several cases exist where ultracapacitors are used on moving vehicles for capture of braking energy and for improving start ups. This paper describes some short-term energy storage applications and the electrical parameters such as power and energy performance that should be considered when selecting a storage option. It also identifies applications where the unique characteristics of ultracapacitors make them a new and viable short-term energy storage solution such as recovery of brake energy from electric transport.
Energy storage system based on double layer capacitor technology - the gateway to high efficient improvement of mass transit power supply by Christian Godbersen, Siemens
Energy saving from regenerative braking require the presence of an accelerating train or tram in the vicinity to absorb the power being produced by a vehicle that is braking. Therefore only a part of this kinetic energy could used by other vehicles. Until now the other part of the energy has to be dissipated as heat in resistance grids on the train. Consequently this energy was lost from the economical and environmental point of view.
Today Energy Storage Systems could optimise the power supply of the public transport. Energy Storage Systems store the surplus energy so that it remains available when required by accelerating vehicles. In addition to saving energy, Energy Storage Systems can stabilise the voltage of the overhead line and provide peak power when it is needed. This can be used to improve the acceleration of trains during peak periods, alternatively, where a line is being extended. The Storage unit can be charged fast by braking vehicles or slowly via the overhead line. It is a matter of course, that the system could switch automatically between the energy saving and voltage stabilising mode.
The first Energy Storage System world-wide, based on the most innovative technology of Double Layer Capacitors, was put into operation in Cologne in May 2001. The first compact Series - Container starts to stabilising the system voltage at Metro de Madrid only one year later, in April 2002. Followed by Systems in Dresden/Germany and Portland/USA. The improvement is demonstrate with numerous measurements and evaluations.
Energy efficiency: a key factor for reaching autonomous electric traction by Jean Chabas, SNCF
The overall objectives of energy efficiency implementation should certainly be reducing cost and guaranteeing to get an everyday cleaner transportation mode. Furthermore, one could consider another, more specific goal, that is extending traction autonomy, especially for electric systems.
Conventional pantograph/catenary based electric traction provides a clean, mature and efficient solution for railway. However there are cases where more flexible, better integrated systems are expected. Moreover, cost of the electrification remains problematic. Therefore, there is a real need for autonomous electric traction, for the entire line or in some cases portions of the line. Different solutions are under consideration, some of which have been closely evaluated or are under current investigation. Among them, THALES project proposes a tram-train vehicle to hoop between consecutive urban stations with onboard energy supply primarily stored on ultracapacitors. Other projects are mainly based on batteries or fuel cell.
As the whole system is considered, aspects as performances and RAMS RAMS Reliability Availability Maintainability and Safety should be now addressed the same way as they are addressed in diesel systems. However, energy density limitation of the considered onboard energy storage leads to a whole new level of the problematic of autonomy.
Consequently, rational use of available energy should be enforced at every stage of the system : Precise management of the stored energy, energy regeneration whenever possible and at optimal efficiency, intelligent advisory driving system taking into account in real time the current condition of each involved equipment, including traffic, and predictive scenarios optimization when considering the next mission. Finally, when running now under catenary on formerly-electrified portions of line, this very equipment will still fulfill the same functions of energy management or power peak leveling using the high power density of the ultracapacitors, leading to an improved efficiency of the whole system.
Increased recuperation efficiency above the sub-stations no-load voltage in a 1500V DC catenary system by Erwinn Meerman, NedTrain Consulting Inc.
In the Netherlands modern train sets recuperate energy when braking. At present the maximum allowed voltage for recuperation is restricted to 1800V, which approximately equals the no-load voltage of the substations. The EN50.163 points towards the voltages from 1800 upto 1950V to be used for recuperation. The potential energy savings using a higher recuperation voltage were investigated. The system used to measure and it’s possibilities are presented. The measurements show that increasing the recuperation voltage above the no-load voltage improves the amount of energy fed back into the catenary. A maximum recuperation voltage equal to the no-load voltage results in an efficiency of approximately 50%, so still half of the recovered energy during braking is dissipated in braking resistors. Increasing the recuperation voltage to 1900V the efficiency increases to almost 80%. The collected measurement data give also insight in the voltage time relation when recuperating. Although promising there are some of annotations to be made; the energy saving and efficiency depends on the number of train sets consuming energy as well as recuperating at the same moment; potential risk of accelerated aging of older components both in rolling stock and infrastructure; governmental railway supervisor, infraprovider/administrator and other operators need to agree on adjustment of national regulations which now prohibit the use of voltages above 1800V.
Railway Electricity supply - area of tension between electricity and railway liberalisation by Johann Pluy, ÖBB
Railways with an electric traction system are usually very large electricity customers in their country, but at the same time “bad” customers for the power suppliers. Due to extreme dynamic load curves whith high and short peaks is purchasing very complex and results often in very high electricity costs. The electric wholesale market is charcterized by two factors: increasing prices (mid and long term prognosis) and extaordinary high intra-day price volatility. On the other hand there are the main customer needs: low and stable (within a planning interval), for calculation suitable electricity prices. So the risk of price and of course quantity must be handled by the railway electricity supplier - typically an operator or an infrastructure company. Because of the electricity market liberalization most of the new railway companies are so called eligible customers. They can buy their energy demand elsewhere on the European energy market and transfer the purchased energy through the catenary to their locomotives. The railway electricity supplier has to handle in future two situations: Supplying customers (fully supply contract) or managing a “non” discriminatory transfer from the connection point to the public high or medium voltage grid through the electric railway grid to the locomotive (contract for using electric railway grid). The transfer of electricity causes a lot of work and a lot of troubles: metering the customers, charging the electric grid are typical problems of a public grid company.
Railway electricity suppliers have to optimize their portfolio with short and long term contracts and their load profile to get competitive electricity prices for the operators. A professional portfoliomanagement is a “must have” for handling the costs and can´t sensitively be replaced by a full service contract, without knowing a lot about pricing-mechanisms, forward prices and their forecasts. Otherwise you couldn´t seriously evaluate the price of such a contract. With an active portfolio management you can also control the production mix regarding the and the exact, current knowledge of the spot and forward price is absolutely necessary. A further detail are determining the energy-portfolio regarding the primary energy-mix to fullfill different customer needs.
This article explains the future developments in the Central-European energy market, taking into consideration the price development and the market structure as well as the consequences for railways. The process “electricity supply for railways” will be discussed in analyzed regarding the purchasing process (portfolio management), pricing the service or retail-product electricity for operators, billing (including metering) and risk management for the overall process. “Grid access” from other power suppliers will be also analyzed and discussed within this contribution.
Environmental guideline for the procurement of new rolling stock (outcome of the UIC project PROSPER PROSPER Procedures for Rolling Stock Procurement with Environmental Requirements ) by Henning Schwartz, DB AG
The environmental performance of transport has come to increasing interest of public discussion in the last two decades. Railway transport is still one of the most environmentally sound modes of transport. To keep this position and further enhance environmental performance as a competition factor towards other modes of transport railways have already done a serious effort so far and will bring this topic forward in the future. With the Strategic Rail Research Agenda 2020, submitted by the European Rail Research Advisory Council (ERRAC ERRAC European Rail Research Advisory Council ), railway industry has defined priorities of research activities up to the year 2020 - environment is one of them. In this context the PROSPER project was approved by UIC Technical and Research Commission (CTR CTR Technical and Research Commission ). PROSPER is the acronym for “Procedures for ROlling Stock Procurement with Environmental Requirements” and addresses environmental requirements in the procurement process of new rolling stock. The PROSPER project started in February 2002 and has as objectives to
- harmonise environmental requirements for the procurement of new rolling stock amongst European railways
- assist in setting up environmental specifications and assessing tenders in the tendering phase for the procurement of rolling stock. The outcome of the project is a UIC Environmental Guideline for the Procurement of new Rolling Stock including a set of recommended environmental specifications. In view of that, the main tasks for the project team were
- to analyse the degree of integration of environmental aspects into the procurement process at railways
- to co-ordinate a set of qualitative environmental specifications to be used in invitations to tender (in PROSPER no performance values have been defined)
- to co-ordinate a harmonised methodological approach how to set up environmental requirements and evaluate tenders (here PROSPER co-operated very closely with the EU funded REPID REPID Rail Environmental Performance Indicators and Data formats project) and
- to give an overview of the cost/ benefit relation of enhancing environmental performance of rolling stock in order to apply the methodology also in a cost efficient way In addition to these efforts another main objective of the project was to improve the dialogue between railways and manufacturers to obtain a common “environmental language”. Given that close co-ordination with manufacturers is a distinct success factor for the acceptance of the Environmental Guideline, an international Network Meeting together with the EU funded REPID project was held with experts both from manufacturers and railways in April 2003 in order to obtain further comments and opinions of different players in the procurement process.
Specification and verification of energy efficient rolling stock by Markus Meyer, Emkamatik GmbH
Today nearly all vehicle specifications ask for energy efficiency, since energy costs are a considerable part of the vehicle’s life cycle costs. Although the demand for energy efficient vehicles is a positive development, the situation is far from being optimal. Normally, low energy consumption of a train is not really honoured financially to the manufacturer of the train, since this is a long term issue. In most of the cases only the purchase price is responsible for the purchaser’s decision. On the other hand, no common understanding has been reached on how to specify and verify the energy consumption of trains. This stands in contrast to the automotive industry, where the consumption of cars is specified and tested for normalised traffic cycles. This enables the customer to take into account the fuel consumption when making his decision for or against a certain model. In order to improve the energy efficiency of the railway system, a similar approach seems to be necessary. The method can be based on one or several load cycles, depending on the nature of the railway vehicle (locomotive, suburban train, high speed train etc.). In the end, the consumption of different trains, or different design options for a given train, can be calculated. This sounds very simple, however, a variety of railway and technology specific issues has to be considered: § the load cycle must reflect the planned type of operation of the vehicle; § many different design parameters for a train influence its energy consumption: running resistance and air drag, losses in the traction chain, auxiliaries, comfort issues (such as air conditioning); § how does the driving of the train influence its energy consumption, and which driving style shall be the basis for the prediction; § how is it possible to verify the promised energy consumption of a train, taking into account the accuracy of measurement instruments, driving, rail conditions, ambient temperature and, especially for locomotives, the composition of the test train; § how can target values be fixed in a contract under consideration of all these aspects The paper will deal with all these aspects, based on model calculations for a typical modern regional train. The model structure and parametrisation will be generic (i.e. not for a specific product), but is based on earlier experiences of the authors and will, therefore, yield valuable results. An important part is a sensitivity analysis, revealing which aspects are really important and which may be neglected without negative consequences. The paper will conclude with a proposal on how energy consumption of trains may be specified and verified in future, e.g. by means of an “energy index”, thought as an input into the discussion between operators and manufacturers of modern trains.
Indicators, leaflet, data on energy UIC feasibility study test cycles energy by Helmut Kuppelwieser, SBB & Markus Halder, DB AG