Controlled charging of electric

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21 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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Controlled charging of electric
vehicles under power constraints



M.Sc. (Tech.) Juuso Lindgren

Aalto University, Dept. of Applied Physics

juuso.lindgren@aalto.fi

2012


2 articles written


1 journal


1 conference


Planned EV review article to become part of a
larger
review article


written in collaboration with Prof. Lund and 2 doctoral students
from the same research group


working title:
Energy system flexibility


a review of measures to
increase variable renewable electricity in the power system


should be ready by end of summer


(EV part might later be extended to its own review article)

Controlled charging of
electric vehicles under
power constraints

2

Charging Strategies for Electric Mobility
Coupled to Electricity System


Journal article


About

1.
How to allocate limited charging power
between different EVs?


smart VS dumb charging

2.
(Estimating effects of EV charging to
electricity price)


smart VS dumb charging


Submitted to
IEEE Transactions on
Smart Grid


Review feedback received on February,
revision in progress

Controlled charging of
electric vehicles under
power constraints

3

Charging Strategies for Electric Mobility Coupled to Electricity System


Methods


Trip generation model


tries to simulate car traffic in Helsinki area


Selected assumptions


10 000 plug
-
in hybrid electric vehicles


Charging only possible at work and home


Max charging power for one socket = 7.4 kW


Total charging power at work is limited to 0.1 kW per EV


low value selected to make differences between strategies more visible


Conclusions


Smart charging can improve electric mileage in Helsinki by

at least
5%


reqs. knowledge of parking time and distance driven before next power grid
connection


“theoretical maximum”: ~10% increase


unlimited total charging power at nodes


charging strategy becomes irrelevant

Controlled charging of
electric vehicles under
power constraints

4

PV
-
to
-
EV Schemes for Photovoltaics
Integration and Power Balance


Conference article


“What was left out of the journal
article”


Submitted to
2
nd

International
Workshop on Integration of Solar
Power into Power Systems

Controlled charging of
electric vehicles under
power constraints

5

PV
-
to
-
EV Schemes for Photovoltaics Integration and Power Balance


Methods & assumptions
largely same, but trip
generation algorithm was
updated


Conclusions


There is a region in
(battery
capacity,charging power)
-
space

where smart charging is effective


Outside this region, dumb
charging is almost
indistinguishable from smart
charging

Controlled charging of
electric vehicles under
power constraints

6

In
-
progress article:

Charging infrastructure at workplace


In previous submissions, we assumed
sufficient

charging sockets


Each vehicle starts recharging with 0 queuing time


Sockets are now
insufficient


There will now be
queueing



Level of detail is increased greatly


N

charging poles

that have
M

wires

and
X

serviceable slots


M

vehicles can charge simultaneously at one pole


a pole can only charge vehicles parked at the serviceable slots


vehicles cannot be moved except by driver, but the wire can


delay for moving the wire (15 minutes)


each pole has its own queue

Controlled charging of
electric vehicles under
power constraints

7

Charging infrastructure at workplace: Preliminary results


How much will the electric mileage improve when charging
infrastructure is added at work?

Controlled charging of
electric vehicles under
power constraints

8

Amount of charging poles per EV

Max power of single wire (kW)

Increased e
-
km per EV (km)

1

2

1

2

3

4

1000 cars simulated, battery capacity 5 kWh, 2 wires per pole,

wire switching delay 15 minutes

Controlled charging of
electric vehicles under
power constraints

9

0
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Pole coefficient at work

Increase of electric
-
km per vehicle (km)

Wire max power at work (kW)

0
0.05
0.1
0.2
0.5
1
0
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Same data with Excel

Extra slides

Controlled charging of
electric vehicles under
power constraints

10

Shape of “significance map”

Controlled charging of
electric vehicles under
power constraints

11

PV
-
to
-
EV Schemes for Photovoltaics
Integration and Power Balance

Controlled charging of
electric vehicles under
power constraints

12

Trajectories in elasticity field

Controlled charging of
electric vehicles under
power constraints

13

Schedule

2012

2013

2014

2015

Publication 1



Revie
w article





Publication 6







Publ. 2







Publication 5













Charging infrastructure













Courses (40 ECTS)

















Controlled charging of
electric vehicles under
power constraints

14

Charging Strategies for Electric Mobility Coupled to Electricity System


Methods


Trip generation model (used in Master’s thesis)


tries to describe car traffic in Helsinki area


Absolute electricity price
-
electricity consumption elasticity field


Selected assumptions


10 000 vehicles


Max charging power for one socket = 7.4 kW


Total charging power at a node is limited


Conclusions


Smart charging can improve electric mileage in Helsinki by at least
5%


“Theoretical maximum”: ~10% increase


Infinite total charging power at nodes


At 10% EV penetration, controlled charging can decrease the standard
deviation of yearly electricity price profile by
16%

compared to 0%
penetration


Uncontrolled charging (business as usual) would increase it by
60%*

Controlled charging of
electric vehicles under
power constraints

15

*) Sounds a bit high and should be taken with a grain of salt. The model starts to break down at around 10% penetration.

PV
-
to
-
EV Schemes for Photovoltaics Integration and Power Balance


Methods & assumptions largely
same, but trip generation
algorithm was updated


Conclusions


There is a region in
(battery
capacity,charging power)
-
space

where smart charging is effective


Outside this region, dumb charging
is almost indistinguishable from
smart charging


At 10% EV penetration, controlled
charging can slightly reduce
average electricity price (
-
0.5%
)


Uncontrolled charging causes it to
increase (
+2%*
)

Controlled charging of
electric vehicles under
power constraints

16

*) Should be taken with a grain of salt. The model starts to break down at around 10% penetration.