>> For Road, Off-Road and Rail Applications page 14

Transcription

1 1 st Issue December 2004 Railway Technology Magazine >> MEE-NT For Regional Traffic page 6 >> For Road, Off-Road and Rail Applications page 14 >> From Paris to Stuttgart by TGV page 16

2 CONTENTS photo: Bombardier photo: ALSTOM photo: Siemens photo: Transrapid International 3 Editorial 4 Ilha Formosa 6 MEE-NT Now Available for Short-Dist ance Traffic 9 For Urban and Rural Applications 10 Grid Interferences of Power Electronic Converters 14 Road, Off-Road, and Rail Applications 16 From Paris to Stuttgart by TGV 18 Rational Handling of Energy 21 Rail Solution Asia in Taipei 22 Keep Cool Rail Focus Railway Technology Magazine Publisher: SMA Technologie AG Hannoversche Str Niestetal Germany Phone Fax Responsible for contents Dirk Wimmer Dirk.Wimmer@SMA.de Coordination Susanne Günther Susanne.Guenther@SMA.de Rail Focus Railway Technology Magazine will be published biannually German edition: International edition: 750 All brand and product names used in this magazine are trademarks or registered trademarks of their respective holders, although they may not be specifically designated as such. Reprints, including excerpts, are subject to written approval from the publisher. Printed on paper made from chlorine-free bleached cellulose SMA Technologie AG. All rights reserved.

3 EDITORIAL Dear readers, We are happy to present the first edition of our new Railway Technology Magazine. Our Rail Focus magazine is to inform you at first hand about SMA s Railway Technology division, to introduce individual projects and to provide you with interesting information on the use of SMA systems. We regularly raise special issues and would like to impart our long experience and wide range of know-how in form of professional articles to those who are interested in technology. In view of the daily information overload we would like to present the essential issues in a clear, simple and understandable form and hope you will have a good time in reading the Rail Focus magazine. We welcome your feedback and suggestions. Please enjoy reading! Railway Technology Management Roland Grebe Birgit Wilde railfocus 3

4 APPLICATION Ilha Formosa! SMA provides energy supplies for Metro in Taiwan More than 400 years ago, the first Europeans passed an island in the Chinese Sea with the Dutch navigator Jan Huygen van Linschoten on board of the Portuguese ship. When he saw the island he called out Ilha Formosa meaning more or less beautiful island. by Dirk Wimmer Still today, formosa stands for Taiwan. Taiwan is still a subtropical island with virgin forests, desert mountain ranges and remote, fantastic sandy beaches. Originally the island was populated by Polynesians. Now, the most of the population of 22 million people are Chinese living in the Western lowland of the island. Taiwan is said to be the second most populous area in the world although the East is only sparsely populated. The second-largest city of Taiwan after Taipei is Kaohsiung with a population of approx. 1.5 million people. Kaohsiung is located at the Southern tip of Taiwan where approx. a total of 3.5 million people, including the surrounding cities, live. Kaohsiung has been affected by heavy industry, mainly Mascot of the Metro company Kaohsiung steel and shipbuilding, and by the container harbor which is the third largest in the world after Hongkong and Singapore. And there is definitely room for growth. Traffic in Kaohsiung is less hectic than in Taipei. However, traffic and air pollution give reason to extensive measures in infrastructure. Many construction projects are currently running in the city of Kaohsiung. The first Metro is being designed a mainly underground transport system of 28 km and with 23 stations for the Red Line and 14 km with 14 stations for the Orange Line. Additional lines and a light-rail system are planned to be opened up. In addition to the tracks, stations and depots, the vehicles are newly constructed as well. The first trains are expected to go into service on a line section at the beginning of The service will be upgraded to the entire line and to 4 railfocus 1 st Issue

5 all vehicles at the beginning of In addition to signal and control technology, catenary design and entire project management, Siemens was commissioned with the supply of 42 Metro trains with three coaches, each, in Each Metro train will be equipped with two auxiliary power supplies MEE-NT SD by SMA. MEE-NT SD is the name for all auxiliary power supplies for short-distance traffic (Metro, tram and regional commuter trains). The systems for CITADIS RegioTram Kassel and CORADIA LIREX Stockholm belong to SMA s new product family as well. MEE-NT SD is based on the proven technology platform MEE-NT (see article pages 6 8). Depot for Metro Kaohsiung under construction Design draft of trains for Metro Kaohsiung photo: Siemens photo: Siemens railfocus 5

6 BACKGROUND MEE-NT Now Available for Short-Dist Since 1999, the multiple input voltage APS (Auxiliary Power Supply) MEE-NT is used by different European operators. For the first time, SMA realized an electric separation in the input stage by a soft switching input converter that can be operated at all UIC input voltages without electromechanical regrouping. More than 250 railway coaches have meanwhile been equipped with multiple input voltage MEE-NTs and prove their reliability in daily use on European railroads. For short- and long-distance traffic by Dirk Wimmer ALSTOM CORADIA Lirex for Lokaltrafik Stockholm, equipped with MEE-NT SD, during final installation at ALSTOM LHB Technology Platform MEE-NT The MEE-NT is a modern proven platform for auxiliary power supply systems for short- and long-distance traffic. The technological advantages of the MEE-NT are available for the MEE-NT SD * and the MEE-NT LD ** as well: Easy and low-cost adjustment to different applications due to modular system concept Lightweight systems due to electric separation in input converter with HF transformers Input converter MEE-NT SD of ALSTOM CORADIA Lirex for the Lokaltrafik Stockholm Compact design with very high efficiency due to resonant switching power units *) SD = Short Distance **) LD = Long Distance 6 railfocus 1 st Issue

7 ance Traffic photo: ALSTOM LHB photo: ALSTOM LHB ALSTOM CITADIS for the RegioTram Kassel, equipped with MEE-NT SD Optional operation under partial load conditions without forced ventilation due to special arrangement of the heat sinks AC output voltages in grid quality with load tolerant neutral wire without additional 50 Hz transformer High power factor and low grid disturbances in input and high output voltage quality due to advanced digital control Easy service, analysis and maintenance due to modern diagnosis system and modular design MEE-NT SD is available as modular system for different applications. Each MEE-NT SD consists of an input converter with electric separation by HF transformers and any number of output modules. Solutions are available for all grid voltages usual in short-distance traffic. Output modules, such as three-phase inverters and battery chargers, complete the system. A DC voltage output for charging the battery and supplying the connected DC voltage consumers is required in almost all systems. Thus, an input converter with an optionally integrated battery charger has been developed for the MEE-NT SD reducing the system costs, weight and required space. SMA also entered new grounds in the development of the enclosure. For the first time, non-welded enclosures that can be mounted under floor and on the roof are available. They can alternatively be manufactured as steel, stainless steel or aluminum enclosures and convince by their low weight. The multiple input voltage MEE-NT LD has continuously been enhanced since its launch in 1999 and is now available as complete system kit. railfocus 7

8 BACKGROUND Multi-voltage capable input converters can be combined with any number of output modules, such as battery chargers and three-phase inverters. The inverters can be operated in fixed or variable frequency mode and generate a load tolerant neutral wire without additional transformer, if required. A number of options, such as automatic train line detections, battery inverters or diagnosis displays, complete the product range. photo: CNL Double-deck couchette coach of the CityNightLine, equipped with multiple input voltage MEE-NT LD Power electronic module of the MEE-NT SD CORADIA Lirex Stockholm MEE-NT SD for ALSTOM CITADIS RegioTram Kassel 8 railfocus 1 st Issue

9 APPLICATION For Urban & Rural Applications First roll-out of the RegioTram Kassel Salzgitter 6 th of July The first RegioTram for Nordhessen rolled out of the hall of the railway technology manufacturer ALSTOM LHB with a great fuss. By December 2004, eight vehicles will connect the cities of Kassel and Warburg in Germany. by Dirk Wimmer photo: ALSTOM LHB Roll-Out of the first RegioCITADIS of ALSTOM for Greater Kassel area, equipped with MEE-NT SD 18 of a total of 28 tram-trains belonging to the family of regional light rail vehicles RegioCITADIS are twosystem vehicles. They are used in Kassel s tram system as well as in the system of the Deutsche Bahn AG. The remaining ten vehicles are new hybrid vehicles that may be driven in electric mode with 750 V DC and in diesel-electric mode as well: They run under the tram s catenary in the city and the integrated diesel engine allows full operation on non-electrified railroads in Kassel s surrounding areas. Kassel Melsungen are scheduled to open in 2005 and SMA provides auxiliary power supplies for the redundant board supply and independently controllable air conditioning units for the tram-trains of RegioTram by order of ALSTOM. SMA realized an innovative and very light weight solution for the vehicles custom-tailored to the requirements of Kassel s tram system and the regional system of the Deutsche Bahn AG. Link: Great reception for the new train: Representatives of ALSTOM, the Nordhessischer Verkehrsverbund (NVV) as well as of the local policy The first eight vehicles have passed extensive test runs and will be used in regular traffic between Kassel and Warburg in December The routes Kassel Wolfhagen and photo: ALSTOM LHB railfocus 9

10 BACKGROUND Grid Interferences of Power Electronic Converters Auxiliary power supplies for rolling stock may affect their environment. This impact is to be restricted to an extent that other equipment is not impaired in its functioning and that damages of persons are impossible. This article describes the most common interferences and indicates the requirements to be considered in developing and producing an auxiliary power supply. by Dirk Wimmer and Andreas Berger Basically, conducted and non-conducted interferences are distinguished. Non-conducted interferences are divided into field-bound and radiated phenomena. In case of field-bound interferences the separately measurable values for the electric and magnetic field are assessed in the near field. For example, limit values for magnetic flux density in the track bed caused by auxiliary power supplies apply in order to avoid impact on sensors. Critical units are e. g. axlecounters used for clear track signalling systems. In addition, the DIN VDE 0884 standard specifies frequency-dependent limit values for electric and magnetic fields referring to personnel protection in order to specifically protect persons with implants, such as pace makers. In case of radiated interferences in the far field the electric and the magnetic fields are not separately measured. Test methods and limit values comply with the values of the classical EMC (Electro Magnetic Compatibility) and are specified in the harmonized EN standard. In case of conducted interferences, interference voltages and parasitic currents above 9 khz as well as test methods and limit values are specified by the EMC standards, specifically by the EN standard. Particularly in case of low frequencies grid interferences are referred to. When considering grid interferences, the impact of current harmonics on the voltage quality of a PCC (Point of Common Coupling) is basically summarized. These coherences that are normally complex are significantly characterized by the grid impedance and the consumers with non-linear current and voltage characteristic according to the frequency ranges to be considered. The ideal case is when the power supply behaves like an ohmic consumer for the frequency of the supplying grid. This means, that a power supply absorbs pure DC current in DC voltage grids and pure AC current in AC voltage grids with a maximum power factor. 10 railfocus 1 st Issue

11 photo: Bombardier Shanghai Movia Metro, equipped with a battery charger based on MEE-NT SD technology While the requirements indicated above aim at the voltage quality at the PCC, limit values assuring interoperability of different electric systems apply as well. In case of AC and DC voltage grids maximum tolerable parasitic currents, such as harmonic currents of a passenger train s influencing units, are defined according to the UIC 550 standard. In addition, operators may require the compliance with specific limit values in order to guarantee the functioning of special communication and signalling systems within their grids. Specifically power electronic actuators may have an undue impact on other consumers and equipment in case of an input current with harmonics. This applies e. g. to clear track signalling systems operating with discrete frequencies. Electric, capacitive or inductive coupling is possible. In case of DC voltage grids a minimum input impedance of the power supply to the feeding grid is specified as well. The reason for this are communication systems, such as the 75 Hz automatic train control in the Dutch 1,500 V DC grid, functioning by modulation of signals onto the DC voltage grid. The power supply may not function as absorption circuit for these discrete signal frequencies. Due to the requirements mentioned above sophisticated auxiliary power supplies must be able to affect the input current in a way that the limit values specified for harmonics are complied with. This may be possible by filtering and controlling the input current. The current is filtered by using passive components, such as inductors and capacitors. However, specifically inductors will quickly have significant additional weight due to the vehicles power requirements. A highly dynamic current control is therefore a better solution that may be adjusted to the different requirements by slight software changes. Solution realized for the MEE-NT When designing the MEE-NT we considered the requirements indi- railfocus 11

12 BACKGROUND Power electronic module of a multiple input voltage MEE-NT LD cated above right from the start. It was possible to comply with these requirements by selecting an optimum pulse frequency, by influencing the input current in terms of control and by an additional inductivity for high frequencies. This concept allows to design a system optimized for low weight that may be projectspecifically adjusted at low costs. In case of the MEE-NT the input current is influenced by the hard switching step-up converter on the input side. The step-up converter controls the voltage via the resonance capacitor for the soft switching inverter connected and at the same time can directly affect the input current by a subordinate, extremely dynamic current control circuit. The MEE-NT makes it possible to limit the grid loads caused by harmonics and to avoid impact on other consumers by complying with the limit values for parasitic currents and input impedance. The compatibility of the MEE-NT was already proven by extensive tests during different projects. The DB AG verifications required for the compliance of the limit values for magnetic fields in tracks could effectively be completed as well. 12 railfocus 1 st Issue

13 Innovative Converter Platform for Long- and Short-Distance Traffic For short- and long-distance traffic System advantages Compact and lightweight system due to sophisticated technology Low-cost adjustment to any coach type Highest reliability High availability due to effective diagnosis Minimum maintenance due to modular system design SMA Technologie AG Hannoversche Strasse Niestetal Germany Phone Fax railtech@sma.de

14 BACKGROUND Road, Off-Road and Computer Technology for Mobile Applications SMA computer systems are used in the Metro that went into service in Bangkok last summer, in new Chinese passenger trains and in the German maglev train Transrapid. The company developed a special know-how for using computers in mobile applications within the last years. This experience can be found in the Enduro MobilePLC and WINtrak fieldbus terminal blocks. by Susanne Günther Railroad-rugged and compact: The Enduro MobilePLC In the field of mobile applications, the demands on computers differ widely and are harsher than in any other area. In the case of railway vehicles, high frequency vibrations occur steadily over long periods of time, whereas excavators and cranes must primarily resist sudden shock impacts. A forestry vehicle must be able to start even at very low temperatures and a harvester has to operate reliably in hot summer weather. EMI immunity is of utmost importance specifically in railway applications (see page 10 12). In addition, the components must be corrosion-resistant when e. g. they are used on board of Metro trains that are usually running in congested areas with sulfurous air. Vehicles are normally very expensive machines. Downtimes are therefore not affordable. In addition, the safety of passengers and transported goods ranks first. This means that the use of industrial computers for vehicles is only possible when, in addition to rigid industrial standards, additional specifications are met. When developing systems for mobile applications, we often refer to the European Railway Standard EN Less is more During the past years, the concept of decentral control has established itself in automation technology. The use of fieldbusses, such as CANopen, made this technological development possible. Modular systems boast several advantages, including simpler wiring which facilitates installation and maintenance, and results in significant weight reduction and financial savings. Decentral control provides additional advantages in mobile applications. Often, the space for electronic components and wiring in vehicles is limited. The amount and therefore also the weight of the wiring must be taken into consideration. That is one reason why conventional connections by means of thick cables is not a good solution. In addition, decentral control systems can be designed as an island architecture, meaning that it is possible to distribute several controls and I/O-nodes within the vehicle. Plus, building redundant systems is 14 railfocus 1 st Issue

15 Rail Applications photo: Transrapid International Transrapid Shanghai: SMA computer for vehicle and section diagnosis and route measurement Vehicles run under harshest environmental conditions very simple and is an important safety feature. Rugged = Enduro For mobile applications, the Enduro MobilePLC coupled with WINtrak field bus terminals is the optimal basis for a decentral control system. The Enduro has two electrically separated CAN interfaces and two Ethernet ports. The PC compatible processor GEODE SC 1100 is designed for fanless operation in the T3 temperature range ( 25 C up to +85 C). After connecting the voltage supply, the Enduro boots the operation system and the application from the integrated CompactFlash. The electronics of the Enduro is sealed by a lacquer and thus protected against environmental influences. In the field of vibrations and broadband noise the Enduro complies with the requirements according to the EN standard, Category Life Testing 1, Class B, mounted at the car body. Vibration resistant = WINtrak Fieldbus terminals for mobile applications are rare. SMA currently provides ten different modules. The modules consist of one base and one electronic module, each. They communicate with the control system via CAN according to the ISO standard. The process interface cable is attached to the base module with tension spring terminals, the electronic elements are simply plugged on. Electronic elements can thus easily be added or exchanged. The Enduro and the WINtrak terminals comply with the EN50155 standard, use the standard CANopen protocol for mobile applications, are complimentary to one another and form a modular control system for simple realization of mobile application solutions at low price. railfocus 15

16 APPLICATION From Paris to Stuttgart by TGV In 1992, Germany and France agreed to build a high-speed line between Paris, Eastern France and Southern Germany. The route from Paris to the East via Lothringen and Saarbrücken to Mannheim is an important step for closing the gap between the German and French high-speed network. by Dirk Wimmer As of 2008, the travel time from Paris to Stuttgart will take only four hours (currently: six hours). Passengers may benefit from this closed gap also on other routes. The travel times between Paris and Frankfurt will be under four hours and between Paris and Munich a bit more than six hours. 15 new TGV POS trains. The new TGV POS power cars are equipped for three different supply voltages (25 kv 50 Hz, 15 kv 16.7 Hz and 1.5 kv DC voltage) and designed for the use within the French and German high-speed network with a maximum travel speed of 320 km/h. Battery and brake charger In addition to new drive technology and multiple input voltage equip- In January 2003, the French Railways SNCF ordered 30 new TGV power cars at ALSTOM. These units are assembled with trailors already available for the TGV-Reseau to form TGV for Korea (KTX) photo: ALSTOM 16 railfocus 1 st Issue

17 Foto: ALSTOM ment of the TGV POS power cars new auxiliary power supplies were used as well. In summer 2003, ALSTOM commissioned SMA to supply battery and brake chargers for the TGV POS. Two battery chargers per power car redundantly provide the 72 V main supply and charge the battery. The brake charger is primarily important for safety. In addition to being fast, high-speed trains need to be able to efficiently and safely break at any time. Electro-dynamic braking via the drives is very important. A brake charger is necessary in order to guarantee electro-dynamic braking in case the catenary or the power converter supplying the traction intermediate circuit fails. In this extreme case, the brake charger is able to supply the two traction intermediate circuits of a traction unit with a minimum voltage from the battery within a few seconds. It is thus possible to ensure functioning of the electro-dynamic brake under these circumstances. Mechanical Integration The mechanical integration of the TGV POS chargers into the specified underfloor configuration was a special challenge. SMA s container technology introduced with the auxiliary power supplies for RegioTram Kassel provides significant advantages in terms of weight. The underfloor enclosures are non-welded aluminum IP65 enclosures with a weight of only 12 kg without fixing rails. SMA battery charger TGV POS in front view with interfaces and revision door railfocus 17

18 BACKGROUND Rational Handling of Energy Innovative power engineering not only for railways In times of raw materials running short it becomes more and more important to use all available energies as effectively as possible. As the consumption of electric energy is increasing worldwide it is so much more important to also use the available energy sources as efficiently as possible. In many cases sophisticated power electronics is essential in order to approach this objective. by Volker Wachenfeld MSA40 Frequency converter for diesel-generator sets with variable speeds Power electronics for diesel-generator sets with variable speed Compared to conventional technology, the use of sophisticated power converter technology combined with permanently excited synchronous machines provides significant advantages when developing mobile power generating sets. Adjusting the speed of the combustion engine to the actual load situation allows to drastically reduce fuel consumption, noise emission and machine wear and tear. Since the output voltage and frequency of the generator is lower than the grid voltage required in case of low speeds, a frequency converter is used for the necessary adjustment. SMA equips dieselgenerator sets with frequency con- 18 railfocus 1 st Issue

19 Illustration: Enginion Illustration: Enginion Design of SteamCell SteamCell is a compact steam powered plant for cogeneration verters of the power classes 5 kva to 44 kva for the Kirsch GmbH in Trier, Germany. Power electronics for steam power plants In conventional combined heat and power plants, the fuel, normally natural gas, is directly combusted in an engine powering a generator. Heat extracted from the generator s cooling circuit is tapped for a heating system. Whereas, the SteamCell initially generates steam that is used to power a specifically developed machine. This machine in turn provides electric power of variable frequency and voltage via a permanently excited synchronous generator. The frequency converter connected feeds the power into the public grid. The generation of steam makes high total efficiencies possible since thermal power for the heating system is not only produced as waste product of engine cooling. The combustion process is more controlled than within an engine. The emission values therefore comply with those of sophisticated boiler heating systems. However, these systems are not able to generate electric current! As the system may be adjusted to almost all kinds of fuels without high efforts it may be used on vehicles or in the field of renewable energy sources, such as biomass energy, as well. Due to a wide range of know-how and the technical basis resulting from many different converter applications SMA was able to provide a specific converter with new features for the SteamCell in best time. The process requires the synchronous machine to be powered as well as slowed down. In addition, the electric power is to be fed into the public grid. Here, SMA could directly rely on the experience of the Solar Technology division. A home power supply on the basis of the SteamCell economically and ecologically friendly feeds the electric power produced into the grid. This power will be used exactly where it is produced without unnecessary transport losses. >>> railfocus 19

20 BACKGROUND Hydro Boy: Inverter for fuel cells Hydro Boy the inverter for fuel cell heating systems Fuel cell heating systems are also plants for cogeneration. In contrast to the SteamCell they generate electric power and heat out of natural gas by an electrochemical reaction. A high electrically efficient and lownoise system with low pollutant emissions is the result. The fuel cell provides DC current. An inverter transforming the DC current into the commonly used AC current is required to feed the current into the public grid. Based on the experience in the field of photovoltaic, SMA has now developed a power inverter for fuel cell applications: the Hydro Boys. In cooperation with partners in the business of heating engineering, SMA has designed the Hydro Boys as a specific solution for fuel cell heating systems. The Hydro Boys are used at a key position in a relatively new technology and will perform efficiently since they are based on SMA s proven and reliable photovoltaic inverters. For more than a year now, about a hundred devices are successfully performing a field test. Fuel cell heating systems with integrated inverter for home power supply are among the most sophisticated systems for transforming fuel into useful energy. They will make an important contribution to a sustainable handling of fossil raw materials still available. The least common denominator of the applications mentioned above is that up-to-date power electronics supports rational handling of the used energy in order to directly save fuel or to decentrally generate electric power with a high total efficiency. We consider this an interesting and, in view of the increasing costs of fossil energy sources, essential task for the future. 20 railfocus 1 st Issue

21 Rail Solution Asia in Taipei NEWS A wide range of projects, from lightrail trains, to Metros and high-speed trains all the way to maglev trains, attract railway technology manufacturers to Asia, especially to China. by Dirk Wimmer Exhibition hall with SMA booth However, Asia is not just China. For example, in Thailand, Korea or Singapore new transportation systems are developed or existing systems are expanded or modernized as well. Compared to China, these countries are very interesting specifically for modernization projects. Many systems have already been in service for some years. Modernizing and/or upgrading the systems is an option often used in view of the vehicles remaining useful life. Countries, such as Vietnam, should be considered as well. Currently, they do not have the financial resources required but may present significant potential in the near future. In order to meet the potential of the market a number of trade exhibitions have been established in Asia. One of these exhibitions is the Rail Solution Asia, a combination of trade exhibition and conference, which takes place every year in another Asian city. The Rail Solution Asia attracts decision makers of many Asian operators, consultants or manufacturers and provides a basis for the establishment of new contacts and for the discussion of concrete projects. The exhibition has a pleasant familiar atmosphere providing the possibility for casual discussions during meetings with snacks and drinks every night. Due to the SARS crisis, the exhibition in Hongkong in 2003 did not fulfill the expectations. In 2004, the exhibition took place in the Taipei International Convention Center (TICC) directly in the heart of Taipei. SMA also participated in the exhibition. SMA s main goal was to present their MEE-NT SD system optimized for the use in short-distance traffic to a broad public. The system convinced large-scale operators in Asia by its advantages, such as low system weight and high modularity. The Taipei International Convention Center in front of the 101-Tower railfocus 21

22 APPLICATION Keep Cool SMA inverter for Bvmz coaches Air-conditioned railway coaches of high quality, such as the Bvmz 185 assembled to locomotive-driven trains are the basis for national and international longdistance traffic of German Railways (DB AG) in addition to motorized high-speed trains (ICE) consisting of fixed train units. The DB AG decided to replace the inverters for the electric supply of the air conditioning by more powerful SMA devices in order to increase travel convenience for the passengers. by Thomas Krämer and Joachim Bierschenk The Bvmz 185 were developed in the 80ies as last generation of railway coaches before the ICE motorized trains. At that time, the high demands on comfort within the Inter- City and EuroCity traffic also in the second class of coach and especially regarding air conditioning could only be fulfilled by the Bpmz coaches developed at the end of the 70ies. The first high-speed track was opened for service in 1988 resulting in the demand for pressure-tight vehicles for use on the high-speed tunnel tracks. In order to close this gap, existing Bpmz coaches were adjusted to be pressure-tight and the DB AG purchased a total of 180 new Bvmz 185 type coaches. New ground was broken in the interior design: ambiences of compartment and open carriage were combined in one vehicle and seamlessly merged into each other. Some of these vehicles have been used for more than 15 years now which is approximately half of a coache s service life. After this time, the vehicles are generally overhauled in order to prepare them for the second half of their service life. In August 2003, the DB AG decided to replace the inverters for the electric supply of the air conditioning system by more powerful SMA devices in order to increase the travel convenience for the passengers in hot summer weather. Concept The inverter supplies the air conditioning system with electric power. It generates a three-phase AC voltage allowing to power the compressor engine of the air condition which produces cooling energy just like a standard refrigerator. Temperature control Temperature control is an essential feature of an air condition. The inverter s output voltage and frequency is varied which is required to operate the compression motor of the air condition with a variable speed. Different refrigerating capacities can therefore be set. The air conditioning control within the vehicle specifies the temperature and refrigerating capacity. Modification In order to save costs when changing the BordBistro and Bvmz coaches the DB AG decided to use the existing enclosures. The SMA inverter s mechanical and electric design had to be adjusted to these enclosures. 22 railfocus 1 st Issue

23 Air con inverter for Bvmz coach The inverter (three-phase inverter) is supplied with 2 x 230 V, 16 2 / 3 Hz by a transformer connected in incoming circuit that is coupled with the train line. The inverter generates a three-phase AC voltage of 3 x 99 to 285 V, 20 to 65 Hz at the output. Technical data The electric and mechanical external interfaces (plugs, blanking plates, etc.) were reproduced to have a new inverter that fits in form and function. Thus, the old inverter may be replaced by the new inverter in a short amount of time and with little efforts by the maintenance workshop of the DB AG. Such a procedure for modifying the vehicles requires considerable logistic efforts since the old enclosure needs to be removed, sent to SMA, reequipped and sent back to the maintenance workshop. The Cooling time available for this procedure is short as the coaches with the new inverters are to be put back into service as fast as possible. Input voltage Output voltage Output frequency Power Harmonic distortion of the output voltage Special features 460 V, 16 2 / 3 / 50 Hz 3 x 90 V to 285 V 20 to 65 Hz, sine 26 kva / 24 kw < 10 % short and open circuit proof 100 % non-symmetric load resistant high overload withstand capability power factor control diagnosis interface forced ventilation temperatures even in hot summer weather. The first devices already prove their efficiency in daily use. Thus, the passengers can travel at convenient BordBistro and Bvmz coaches are equipped with SMA inverters photo: DB AG railfocus 23

24 Railway Technology Magazine photo: CNL photo: Transrapid International photo: ALSTOM LHB SMA Technologie AG Hannoversche Strasse Niestetal Germany Phone Fax RailF01-02:AE0805