DRESDEN Energy-saving potential of energy storage systems in

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RESEARCH FOR A MOBILE FUTURE

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DRESDEN

Energy-saving potential of energy storage systems

in public transport networks

TROLLEY Summer University Leipzig, 25th October 2012

Sven Klausner

Dipl.-Ing. (FH)

FRAUNHOFER INSTITUTE FOR TRANSPORTATION AND INFRASTRUCTURE SYSTEMS IVI

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� Energy-saving potential using the example of a modern tram


Outline

� Technical description of a supercapacitor-based energy storage system

� Network simulation model of the Fraunhofer IVI for electricvehicles with integrated energy storage system

� Calculation example: Trolleybus with energy storage system (BBG Eberswalde)

� Summary




� Summary

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Outline




� Summary




� Summary

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Energy-saving potential

Influencing factors

Variable vehicle configurationsVariable network conditions (track + power supply)Variable operational requirementVariable ambient conditions

� Vehicle equipment and performance

� Level of motorization and facilities(heating, air conditioning)

� Acceleration, speed, weight

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Influencing factors


� Topography of rail track and network

� Distance between stops, grade of track

� Feeding sectors, coupling of trolley system

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Influencing factors


� Operational and schedule problems

� Work and holiday traffic, weekend

� Construction sites, maintenance

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Influencing factors


� Ambient temperature

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AB1

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AB1 Könnten Sie hierzu noch einen Stichpunkt bringen, damit alle Einflussfaktoren abgehandelt werden?Adler, Bettina; 10.10.2012

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� Network simulations have to consider a multitude of influencing factors

� Measurement of braking resistance during normal operation can easily identify the energy-saving potential


Influencing factors


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AB2

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AB2 oder ist unused breaking energy im Englischen besser für Bremswiderstand?Adler, Bettina; 10.10.2012

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� Field experiment over a period of 9 months

� 45-m tram without air conditioning for the passenger compartement (NGTD12)

� Normal vehicle operation

� Measurement equipment without intervention in the vehicle control system

� Current and voltage measurement with high local and temporal resolution (5 Hz, GPS)

� Comprehensive software tools for data processing and analysis


Measurement

Visualization of measurement data – velocity (Source of backround picture: GoogleEarth)

Source: DVB AG

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Results

Energy into the braking resistors (EBR / distance) in kWh/km

relating to the available braking energy from the propulsion motors

Used braking energy (vevicle + network): (EM,AUX +EM,OL) / EM-

Energy into the braking resistors : EM,BR / EM-

BR – braking resistor

OL – overhead line

M – propulsion motor

AUX – auxilliary consumer

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Winter T ≤ 5°C

Urban centre

15%85%0,39

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Results

Summer T ≥ 15°C

Winter T ≤ 5°C

Annual

Overall network Suburban areaUrban centre

55%45%

76%24%

33%67%

44%56%

59%41%

27%78%

31%69%

45%55%

15%

1,18

85%

1,60

0,58

1,45

2,07

0,77

0,80

1,13

0,39

Energy-saving potential is significantly

influenced by the network topology and the

ambient temperature

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� Network simulation model of Fraunhofer IVI for electricvehicles with integrated energy storage system


� Summary

� Network simulation model of Fraunhofer IVI for electricvehicles with integrated energy storage system


� Summary

Outline


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� Cathode and anode filament wound

� Electrostatic energy storage �high economic lifetime

� Low energy density in comparison with batteries �Improvement by factor 2 in the last 10 years �Integration into a public transport vehicle possible

� Operational voltage range (typical) 1,0I2,55 V

Source: Maxwell

SCAP

Single cell

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SCAP

Single cell

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SCAP

Storage system

� Serial coupling of single cells �Voltage range of several 100V

� Parallel coupling of cell strand�Increase of energy content

� Single cell monitoring (voltage) and module control (temperature)

� Cell voltage balancing �

not suitable for dynamic operation

� Mostly convective cooling/ventilation �

liquid cooling unusual

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SCAP

Power electronic coupling

� Selection of operational voltage range is a question of efficiency optimization

� High operational voltage favorable (Ploss � for P=constant)

� Effort for power electronic is dependent on the DC link voltage

� Not only air cooling but also liquid cooling (water/glycol) usable for power electronic

� Higher power losses caused by additional passive components

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� Summary


� Summary

Outline




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Network simulation model

Trolley system, physical

� Three rectifier substations� Three rectifier substations

� Not illustrated: powered sections, input leads, couplings, breaker� Not illustrated: powered sections, input leads, couplings, breaker

Source : Google

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»Kilometrage«

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Trolley system, modelled

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Vehicle model

� Switched model

� Power consumption from overhead line � current source Power dissipation � voltage source

� Participation of energy storage system by control strategyParticipation of braking resistor above specified voltage level

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Program sequence

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Example: reduced power

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� Summary� Summary

Outline






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Calculation example

Route services

� 2f: Ostend � BV � Kleiner Stern 2b: Kleiner Stern � Ostend� 2f: Ostend � BV � Kleiner Stern 2b: Kleiner Stern � Ostend

Source : Google

� 1f: Nordend � Kleiner Stern 1b: Kleiner Stern � BV � Nordend

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Calculation example

Schedule sections

� Annual mean: 65% »Scenario 1« / 35% »Scenario 2«� Annual mean: 65% »Scenario 1« / 35% »Scenario 2«

� Scenario 1: »work traffic« Scenario 2: »holiday traffic«

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Calculation example

Vehicles

Source : BBG Eberswalde

� Annual mean : 42 weeks »summer« / 10 weeks »winter«� Annual mean : 42 weeks »summer« / 10 weeks »winter«

� Prior use of braking energy for heating/air conditioning

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AB3

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AB3 Das Foto hat eine sehr schlechte Auflösung. Haben Sie noch ein besseres?Adler, Bettina; 10.10.2012

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Calculation example

Operational profiles

� Derivation of the 4 required profiles by data processing� Derivation of the 4 required profiles by data processing

� Measurement of operational profiles over a period of 6 weeks

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Calculation example

Specific energy demand

� Significant influence of velocity within the area of substation west� Significant influence of velocity within the area of substation west

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Calculation example

Energy-saving potential by SCAP

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� Summary� Summary

Outline






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� For determination of the potential of so far unused brakingenergy the measurement and data processing is a moderate method.

Summary

� For economic utilization of available braking energy fordecreasing the energy demand, a custom-designeddimensioning of energy storage component and power

electronics is required.

� An appropriate base for the decision process for the trackand fleet specific purchase of energy storage systems canbe worked out by a network simulation of the energystorage operation (mobile/stationary).

� An appropriate base for the decision process for the trackand fleet specific purchase of energy storage systems canbe worked out by a network simulation of the energystorage operation (mobile/stationary).

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AB4

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AB4 Hier würde ich die Stichpunkte enorm kürzen. Nur das wichtigste, den Rest kann man ja erzählen. Sonst ist Ihr Publikum nur mit Lesen beschäftigt und hört Ihnen nicht mehr zu. :)Adler, Bettina; 10.10.2012

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QUESTIONS AND COMMENTS

DRESDEN

Energy-saving potential of energy storage systems in

public transport networks

Sven Klausner

Email: [email protected]: +49 (0) 351 4640-812

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� Project executing organization VDI/VDE

� Two particular projects with (partial) identical project partners

� Coordination by Fraunhofer IVI (Dr. Thoralf Knote)

Project SEB

Schnellladesysteme für ElektroBusse im ÖPNV

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� Duration: 02/2012 – 01/2015

� Project budget IVI: 3 employees, 200 T€ for material

� Further partners: Göppel Bus, TÜV Rheinland

Particular project EDDA

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AB5

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AB5 Wofür steht particular? Ich würde nur "Project EDDA" schreiben.Adler, Bettina; 10.10.2012

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DRESDEN Energy-saving potential of energy storage systems in