The energy requirement of battery electric vehicles under different … · 2013. 1. 14. · Range...

The energy requirement of battery electric vehicles under different conditions

4th EVE Meeting - 65th GRPE 14th - 18th of January 2013, Geneva

Dr. Werner Tober [email protected]

4th EVE Meeting – 65th GRPE The energy requirement of battery electric vehicles under different conditions

14th - 18th of January 2013 | Geneva | W. Tober | Slide 2

Contents

¨  Database

¨  Analysed e-cars

¨  Test and measurement setup

¨  Results -  Energy requirement as a function of the -  driving situation -  ambient temperature -  road gradient

-  Energy required for a full charge as a function of the ambient temperature -  Range of the e-cars under real operating conditions

¨  Summary



Database

¨  Study Battery Electric Vehicles in Practice - Costs, Range, Environment, Convenience (2nd extended and corrected edition)

¨  Study and detailed data are on www.oevk.at free available for download.

¨  Motivation and objectives of the study -  Electro mobility is widely regarded as the solution for the future mobility. -  Politics and media see an effective way in the electrification -  to increase the energy efficiency, -  to reduce the dependence on fossil fuels and -  to significant lowering the greenhouse gas emissions.

-  How big are the advantages of battery electric vehicles -  based on real operating conditions over an entire year and -  if the energy supply is taken into account?



Analysed e-cars

¨  Mitsubishi i-MiEV

¨  Smart Fortwo Electric Drive

¨  Mercedes Benz A-Klasse E-Cell

¨  Nissan Leaf

¨  Citroén Berlingo (ZEBRA... Sodium nickel chloride)

Photo: Heinz Henninger Photo: Heinz Henninger

Photo: Heinz Henninger Photo: Heinz Henninger

Li-Ion Li-Ion

Li-Ion Li-Ion

Foto: Johann Wolf

Zebra



Used test cycles Eco-Test and Stop-and-Go

¨  The Eco-Test cycle consist of existing test cycles with an overall length of 35,506 km.

0

25

50

75

100

125

150

0 500 1.000 1.500 2.000 2.500 3.000

Spe

ed [k

m/h

]

Time [s]

Test cycles Distance [km] NEFZ ECE 3,920 CADC Urban 4,930 Urban 24,93%

Test cycles Distance [km] NEFZ EUDC 6,920 CADC Extra Urban 8,966 Extra urban 44,74%

Test cycles Distance [km] BAB 130 9,270 Access/exit 1,500 Motorway 30,33%



Measurement setup To analyse the losings and to set up a energy balance

¨  Current and voltage measurement to analyse the required electric power and the energy consumption.

E- motor

Inverter DC/AC

On-board Charger

High-voltage battery

220 V mains

Air

cond

ition

ing

Heating

Transmission

DC/DC converter

N1 to N6: low-voltage consumer units such as coolant pump e-technology, coolant pump vehicle interior, vehicle interior fan, seat heaters etc.

Low-voltage battery N1 N2 N6 …

220 V ~ 300 V = 12 V = 300 V ~

Measuring system



Measurement technology requirements

¨  Currents up until 500 A.

¨  Voltage up until 600 V.

¨  Current sensors need to have: -  high linearity -  low offset -  high band width -  small phase error -  temperature stability

¨  No interaction of the current measurement system with the car electronics

¨  High sampling rate (up until 400 kHz necessary, depends on the inverter).

¨  Variable sampling rate (e.g. temperature at 1 Hz)

¨  High processing power for high calculation rates (up until 200 kHz, in real time)



Contents

¨  Database

¨  Analysed e-cars

¨  Test and measurement setup

¨  Results -  Energy requirement as a function of the -  driving situation -  ambient temperature -  road gradient

-  Energy required for a full charge as a function of the ambient temperature -  Range of the e-cars under real operating conditions

¨  Summary



Energy requirement as a function of the driving situation iMiEV and Smart

¨  The energy requirement is proportional to the required power.

¨  Basically it´s equal to the driving speed ç Does not apply for dynamic driving.

0

5

10

15

20

25

30

Ener

gy re

quire

men

t [kW

h/10

0km

]

i-MiEV Smart

Steady speed

0% road gradient 20°C ambient temperature (without heating and air conditioning)

23 18 65 101/83 40 km/h

A higher average speed ist not equatable to a higher energy consumption.



Energy requirement as a function of the driving situation E-Cell, Leaf and Berlingo

¨  The energy requirement depends also on the load point (efficiency) of the electric motor.

Steady speed

0

5

10

15

20

25

30

Ener

gy re

quire

men

t [kW

h/10

0km

]

E-Cell Leaf Berlingo

0% road gradient 20°C ambient temperature (without heating and air conditioning)

23 18 65 102/88*) 40 km/h

*) Berlingo



Energy requirement as a function of the ambient temperature

¨  Heating and cooling have also a influence on the 12 V energy requirement.

¨  The total add. energy req. for climat. @ +10°C: 10 - 20 %, @ -10°C: 40 - 55%

0

5

10

15

20

25

30

35

40 +3

0°C

+2

0°C

+1

0°C

0°

C

-10°

C

-20°

C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

Ener

gy re

quire

men

t [kW

h/10

0km

] Heating/Cooling 12V network (incl. interior fan) Driving

i-MiEV Smart E-Cell Leaf

0% road gradient, 22°C interior temperature, Eco-Test



Energy requirement as a function of the road gradient

¨  A +2% road gradient results in 30-50% higher energy consumption.

¨  The energy saving at -2% is nearly as high as the higher energy demand at +2%.

0

5

10

15

20

25

30

Smart E-Cell Leaf Berlingo

Ener

gy re

quire

men

t [kW

h/10

0km

]

+2%

-2%

0%

20°C ambient temperature (without heating and air conditioning) Eco-Test



Energy required for a full charge as a function of the ambient temperature ¨  Up to -10°C only ≈ 5% less capacity (prior to start) will be observed.

¨  Charging and discharging losses increase with low temperatures.

0

10

20

30

40

50

60

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

+30°

C

+20°

C

+10°

C

0°C

-1

0°C

-2

0°C

Ener

gy re

quire

men

t [kW

h] Discharging losses

Charging losses incl. charge regulation (12V network) Capacity prior to start of run

i-MiEV Smart E-Cell Leaf Berlingo

10-25% 5-10% (20%)

16 kWh*) 17,6 kWh*) 36 kWh*) 24 kWh*) 23,5 kWh*)

*) Battery capacity as stated by manufacturer

Li-Ion Zebra



101 108

88 73

66 57

0

20

40

60

80

100

120

140

160

180

200

+30°C +20°C +10°C 0°C -10°C -20°C

Range of the Mitsubishi i-MiEV Battery capacity as stated by manufacturer [kWh]: 16 Measured: 14,1-15,3

¨  Average power demand in the Eco-Test at -20 °C: e-motor 5,7 kW

heating 3,8 kW

road gradient 0 %

Interior temperature 22 °C

↓... Energy reserve 25 km

Test cycle: Eco-Test

kWh/100km… at driving operation

21,0*

kWh/ 100km

13,6 kWh/

100km

Ran

ge in

km

at

max

imum

pos

sibl

e di

scha

rge

*…incl. heating

Heating Air conditioning

Ambient temperature in °C



Range of the Smart Fortwo Electric Drive Battery capacity as stated by manufacturer [kWh]: 17,6 Measured: 16,5-17,8

¨  Moderate range advantages compared to the i-MiEV, because -  of the effective higher useable battery capacity of 3 kWh and -  the lower energy consumption (below +20°C).

97

125 106

89 77 70

0

20

40

60

80

100

120

140

160

180

200

+30°C +20°C +10°C 0°C -10°C -20°C

18,9*

kWh/ 100km

14,3 kWh/

100km

road gradient +/- 2 %





*…incl. heating


Ran

ge in

km

at

max

imum

pos

sibl

e di

scha

rge




Range of the Mercedes Benz A-Klasse E-Cell Battery capacity as stated by manufacturer [kWh]: 36 Measured: 32,4-34,7

¨  Caused by the higher battery capacity, -  despite the (class-related) higher energy consumption, -  much higher ranges can be achieved.

147

175

147

126 110

90

0

20

40

60

80

100

120

140

160

180

200

+30°C +20°C +10°C 0°C -10°C -20°C

26,2*

kWh/ 100km

19,8 kWh/

100km







*…incl. heating

Ran

ge in

km

at

max

imum

pos

sibl

e di

scha

rge

Certainly: Charging time @ 220 V, 16 A, ≈ 15,5 h




Range of the Nissan Leaf Battery capacity as stated by manufacturer [kWh]: 24 Measured: 16,9-19,6

¨  The energy consumption per kilometer is less than that of the E-Cell.

¨  The lower useable battery capacity leads to moderate ranges.

95 101 90 78

66 56

0

20

40

60

80

100

120

140

160

180

200

+30°C +20°C +10°C 0°C -10°C -20°C

24,5*

kWh/ 100km

19,2 kWh/

100km






*…incl. heating


Ran

ge in

km

at

max

imum

pos

sibl

e di

scha

rge




¨  Less impact on the range due to a gasoline heater as interior heater and the absence of an A/C (FC interior heater @ +10°C -> -20°C: 0,4 - 1,3 l/100 km)

¨  Need to preserve the battery temp. @ +20°C -> -20°C: 100 -> 229 Wh/h (from 230V grid)

86 85 81 79 76 68

0

20

40

60

80

100

120

140

160

180

200

+30°C +20°C +10°C 0°C -10°C -20°C

Range of the Citroén Berlingo Battery capacity as stated by manufacturer [kWh]: 23,5 Measured: 14,9-16,5

20,6*

kWh/ 100km

19,2 kWh/

100km






*…incl. heating


Ran

ge in

km

at

max

imum

pos

sibl

e di

scha

rge




Summary

¨  The energy requirement is basically proportional to (const.) driving speeds, but dynamic driving causes higher required power.

¨  The average speed is not qualifed to provide info about the required power. Therefore: A higher average speed ist not equatable to a higher energy consumption.

¨  Low ambient temperatures (-20°C) causes up to 70% higher energy consumption.

¨  A road gradient of only +2% increases the energy consumption by 30-50%.

¨  Charging and discharging losses increase with low temperatures clearly.

¨  The ranges of the e-cars under real operating conditions are reduced by half between +20°C and -20°C. Difference to type approval value not taken into account.

¨  Study Battery Electric Vehicles in Practice - Costs, Range, Environment, Convenience (2nd extended and corrected edition) and detailed data are on www.oevk.at free available for download.

Thank you for your attention!

Dr. Werner Tober [email protected]

The energy requirement of battery electric vehicles under different … · 2013. 1. 14. · Range...

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