Auxiliary Power Supply for the CORADIA LIREXTM Stockholm

SMA provides auxiliary power supplies for a total of 55 commuter trains forStorstockholm Lokaltrafik (SL). They are manufactured by ALSTOM LHB in Salzgitterand belong to the family of regional commuter trains CORADIATM.

Compact, innovative and lightweight auxiliarypower supply

Train-wide redundancy due to parallel operation of all converters

Load tolerant neutral wire without additionaltransformer

Based on proven, modular platform MEE-NTSD

High overload ability of the converters

Integrated workshop supply from 3 x 400 V AC

Operation from 1 kV ACpossible

Compact and lightweightinput filters due to highlydynamic input currentcontrol

Ultra-lightweight, non-welded aluminumenclosure

Figure 1: CORADIA LIREXTM for Storstockholm Lokaltrafik (SL)

The auxiliary power supply forCORADIA LIREXTM for StorstockholmLokaltrafik (SL) belongs to SMA'sproduct family MEE-NTSD (SD =Short Distance) for regional trainsand is based on the MEE-NT plat-form. SMA has thus an innovativeand sophisticated modular platformproven in daily use for auxiliarypower supplies in different applica-tions.

Redundancy Concept

All converters of the auxiliary powersupply in the CORADIA LIREXTM for SLoperate in parallel. In case of a failurewithin a device, this device is switchedoff and disconnected while all otherdevices continue operation. The sup-ply of the train is not interrupted.

Design

The auxiliary power supply is pow-ered with an input voltage between900 and 1,800 V DC from the DClink of the traction converters. Oper-ation at 1 kV AC or via a workshopsupply with 3 x 400 V AC is providedas well. The auxiliary power supply

system consists of the function unitsindicated below:· high-voltage input converter· 3-phase output inverter· battery charger· 3-phase battery inverter

Additional functional components,such as coupling contactors, fuses oremergency start-up batteries, arealready integrated into the auxiliarypower supply.

The high-voltage input converter fea-tures two compact and lightweightelectronic modules with appropriateinductive components. This convertergenerates a train-wide, electricallyseparated DC link of +/- 400 V DCout of the different input voltages. Theoutput inverters and battery chargersare connected to this DC link. Eachinput converter has a nominal powerof 125 kW. Due to parallel oper-ation, a total power of 250 kW isavailable at the DC link. In case an

Innovative, redundant auxiliary power supply for sophisticated commuter trains

Figure 2: Block circuit diagram of the train-wide auxiliary power supply realized with the MEE-NTSD

Copyright Alstom 2005

for CORADIA LIREXTM Stockholm

input converter fails the train-wide DCpower available is reduced to 125 kWresulting in continued train operationwith reduced air conditioning.

Each battery charger features abattery charging control with temper-ature compensation, a battery cur-rent control and an output currentlimitation. The two battery chargerssupply a train-wide 110 V DC line. AllDC consumers as well as the batteryinverters for emergency operationthat are integrated in the auxiliarypower supply system are connectedto the 110 V DC line. If one batterycharger fails the second chargerassumes its loads. Unrestrictive trainoperation remains possible.

Figure 3: Detail view of an MEE-NTSD input converter module

Figure 4: MEE-NTSD output inverter modules with a nominal power of 105 kVA and control unit installed

Inverter with high overload

The 3-phase output inverters with anominal power of 105 kVA eachprovide a train-wide 3 x 230 / 400 VAC line. The inverters generate agrounded, load tolerant neutralwire that may be loaded with up to10 kVA. In case of overload, eachoutput inverter temporarily providesa power of up to 210 kVA. If oneoutput inverter fails the secondinverter assumes its loads. Unre-stricted train operation remainspossible.

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Non-welded aluminum enclosures

Each input converter is installed into aroof-mounted aluminum enclosure to-gether with the integrated input con-tactors, rectifiers and fuses, emergen-cy starting units, inductive componentsand the necessary cooling equipment.The container's total weight is 490 kg.

All roof-mounted enclosures are non-welded aluminum containers makingit possible to design ultra-lightweightenclosures. A modular system is alsoused for the containers allowing tosimply adjust them to the vehiclerequirements.

Figure 5: MEE-NTSD input converter with inductive components, cooling equipment and additional components in roof-mounted, non-welded aluminum enclosure

All output converters are mountedinto a second, compact enclosuretogether with the necessary inductivecomponents (e.g. sinewave filterchokes), the cooling equipment andcentral control unit with interface tothe vehicle bus. The total weight ofthis container is 530 kg.

In addition to the requirements refer-ring to modularity and noise emis-sion, specifically the ambient condi-tions in the region of Stockholm(e.g. windblown snow) were con-sidered during development of theenclosure technology (in coopera-tion with ALSTOM and SL).

Conclusion

SMA's MEE-NTSD is a sophisticatedplatform of auxiliary power sup-plies for short-distance traffic. Thisauxiliary power supply featurespower converters operating in paral-lel for reasons of redundancy.Based on this innovative and trend-setting platform it was possible todevelop an ultra-lightweight auxil-iary power supply for CORADIALIREXTM of SL.

Input voltage 1.5 kV DCDC line +/- 400 V DC, 125 kWAC output 3 x 230 / 400 V, 50 Hz, 105 kVAAC overload 210 kVA for up to 60 sDC output 110 V DC, 180 AAC output emergency inverter 3 x 230 / 400 V, 50 Hz, 7.5 kVADimensions: 2 containers of resp. 1,800 x 1,200 x 460 (mm)Total weight 1,020 kg

Technical Data(Auxiliary power supply per half-train)

SMA Railway Technology GmbH

Miramstrasse 8734123 KasselGermanyTel. +49 561 50634-6000Fax +49 561 50634-6001E-Mail: Info@SMA-Railway.com www.SMA-Railway.com