1. No category

Charging of electric vehicles
as reserves of power systems
eCharge –workpackage
ECV-seminar, TTY, 10.3.2015
Pertti Järventausta
Tampereen teknillinen yliopisto (TTY)
Smart Grids - future energy systems
- distributed energy resources with fully integrated network management
Smart grids has two main functions, which are challenges to the distribution system:
1) Enabler of energy-efficient and environmentally friendly open energy market
– interactive customer interface, integration of active resources, demand response,
common market models and comprehensive ICT solutions
2) Critical infrastructure of
society
fault and major
disturbance management
self-healing networks
island operation and
microgrids
UPS systems
Challenge in integration of renewable energy sources
- availability of emission free balance power
Production
Consumption
• Wind and solar power requires more balance power
• Smart Grid enables balance by interconnected networks and also by
integrated active small resources
Demand Side Management (DSM) and
Demand Response (DR)
Reference: (Bartholomew, Callender, Hindes 2009)
Using small resources in ancillary service markets
Two different cases are calculated
– small electricity consumers and
– medium electricity consumers
Case
Small consumers
Medium consumers
Number
of loads
10 000
400
The “ancillary service markets” are
– frequency regulation (FR)
– frequency controlled disturbance reserves (FCDR)
– manually controlled disturbance reserves (MCDR)
– balancing market (BM).
Average annual mean power
of the individual loads (kW)
1.2
30
Average peak power of the
individual loads (kW)*
10
80
Frequency dependent charging
•
Plug-in vehicles will be a remarkable load
•
New load brings new challenges...but also opportunities
•
Ancillary services provided by frequency dependence
– frequency regulation, disturbance reserve, …
•
Active power drawn by the charger is made dependent of locally measured grid
frequency new dynamic load
ancillary services
Electric vehicles as resources of Smart Grids
•
Possible roles of EVs in Smart Grids
– New load (charging)
3/13/2015
A simulated case study of distribution network
•
Real distribution network supplied from 110/20 kV primary substation having
457 km 20 kV network and 793 km 0.4 kV network, 469 secondary substation
and 7612 customer
•
Roughly half of the customers have an EV with “dumb” and “slow” charging
Peak powers of the MV feeders
Electric vehicles as resources of Smart Grids
•
Possible roles of EVs in Smart Grids
– New load (charging)
– Controllable load
• EV charging can be controlled at least as
– on/off (~switch)
– adjustment of charging current
3/13/2015
Electric vehicles as resources of Smart Grids
•
Possible roles of EVs in Smart Grids
– New load (charging)
– Controllable load
• EV charging can be controlled at least as
– on/off (~switch)
– adjustment of charging current
– Controllable energy storage
• Vehicle-to-grid – “V2G”
• Vehicle-to-home – “V2H”
3/13/2015
EV as a controllable load or energy storage
Possible use of electric vehicles as resources of Smart Grids
Actor
Use
Energy retailers
• Electricity trade optimization
• Balance management
• Balancing market operation
Distribution network
operators
• Network management
(long term planning and real time operation)
Transmission system
operator
• Disturbance reserves (manually or automatically
activated)
• Frequency regulation
Individual electricity
consumer
•
•
•
•
Backup power
Peak load management
Energy cost optimization
Power quality improvement
13.3.2015
Role of service provider in intelligent charging
Intelligent charging /
frequency controlled charging
Älykäs latausjärjestelmä
• taajuus- ja/tai jänniteohjatun
lataustehon ohjaus
• muu ohjaus
49.85 Hz?
203.5 V?
Frequency
value
Output
control
0.01 Hz
accuracy
PWM signal
adjustment
Fast
sampling
Charge
current
limitation
Logging and
reporting
Logging past events
and submitting
information
Status of available
reserve?
Electric vehicle charging stations as
aggregated frequency containment
reserves (FCR)
Mika Lötjönen
(mika.lotjonen@tut.fi)
Introduction
•
Electric vehicles as aggregated FCR
– objective is to find out the impacts
• under disturbances FCR-D,
• under normal conditions FCR-N
•
PSCAD is utilized for the simulations
•
Power system utilized consists of three voltage levels
– a simplified equivalent of the transmission grid (HV) for frequency
phenomena studies (source Fingrid)
– distribution system consisting of MV and LV equivalents from
Tampere (source Tampereen Sähkölaitos)
• the distribution model is connected to the main grid via HV/MV
• charging stations are on the LV-side
Finnish grid equivalent
•
Hihgly simplified equivalent model reflects
the structure of Finnish main grid and it
consists of 8 nodes which define the 400 kV
transmission system
generation and loads are connected to
the 400 kV nodes via HV/MV
transformers
the model is feasible for frequency
phenomena studies
3-bus, 2-generator
equivalent for rest
of Nordic system
• The effect of the rest of the Nordic power
system on frequency response is modelled
via two equivalent dynamic generators
the two equivalents emulate on general
level the effect of the inertia and the
frequency reserves in other Nordic
countries
Finnish grid equivalent
Distribution system (source Tampereen Sähkölaitos)
10 to 20 nodes in each MV / LV -model
Latausasema 1
Latausasema
solmupisteessä 7
M0408
RRL
1
M0290
2
RL
M0 198
3
RL
M02 24
4
RL
M0020
5
RL
P+jQ
6
RL
RL
#1
Tämä on
lat ausasema
bussille
7
RL
#1
#1
#1
#1
#1
#1
#1
M0431
#2
#2
#2
#2
#2
#2
#2
3 Phase
RMS
8
P+jQ
#1
Pyynikintori
P+jQ
P+jQ
P+jQ
P+jQ
P+jQ
#2
P+jQ
P+jQ
3 Phase
RMS
#2
P+jQ
M01659
#1
V7
#2
#2
P+jQ
3 Phase
RMS
Bus_PJ1
M0354
RL
V10
RL
RL
RRL
1
#1
#2
R
R
3 Phase
RMS
V1
R
RL
RL
RL
RL
RL
RL
P+jQ
P+jQ
P+jQ
M0005
RL
#1
P+jQ
9
RL
#1
MV-distribution system model
10
RL
P+jQ P+jQ P+jQ P+jQ P+jQ P+jQ P+jQ
11
P+jQ P+jQ
V1
#2
LV-distribution system model
Electric vehicles as FCR
•
Frequency limits set by the Grid Code
– Normal operation
• f = 49,9 …50,1 Hz
• no action taken
– Activation of FCR
• frequency is outside the normal
operation limits
•
•
Electric vehicles as FCR
– under disturbances and normal
conditions
• activation of reserves outside the
normal operation frequency limits
• utilizing the charger models
available (AC/DC/(DC))
Other reserve loads and reserve power
machines also utilized
Main : Graphs
50.250
ftf
fFFT2
49.916
Frequency reaches
minimum limit
49.869
-0.047
Min 49.868
49.800
1.20
1.00
0.80
0.60
0.40
0.20
0.00
80
70
60
50
40
30
20
10
0
x
0.0
80
70
60
50
40
30
20
10
0
cont rol_1s
1.000
Frequency
reserve is
activated
0.000
-1.000
Min 0.000
Pload_cont rol
71.087
Power to the
charging system
Is turned off
2.0
4.0
6.0
8.0
10.0
12.0
0.637
-70.450
Min 0.637
14.0
16.0
6.8
8.3
f 0.7
Pload_control_PI
PI-controlled
charging
Electric vehicles as FCR
71.111
0.065
-71.046
Min 0.065
LUT, eCharge, Frequency control
50.2
Over frequency
50.15
Overall target:
• Developing simulation models related to
frequency control in smart grid
environment (and demonstrations)
Frequency ( Hz )
•
50.1
Upper limit of dead band, for instance +0.05 Hz
50.05
50
49.95
Lower limit of dead band, for instance -0.05 Hz
49.9
Under frequency
49.85
49.8
01.10 21:30
01.10 21:45
01.10 22:00
01.10 22:15
01.10 22:30
12
Load increased
19
Current status:
• Frequency control developed,
implemented and tested in Green
Campus environment
• Possbility to demonstrate frequency
controlled charging with commercial
products (charging poles and EV)
Power
•
10
8
6
Normal operation of the load, 6 MW
Load decreased
4
2
0
Jukka Lassila, LUT 10.3.2015
LUT GREEN CAMPUS DEMONSTRATIONS
Älykäs sähköinen liikenne
Smart charging
• Latauksen ohjaus puhtaasti kaupallisia tuotteita ja olemassa olevaa
infraa hyödyntäen
• Kaupallinen sähköauto – kaupallinen lataustolppa –
tietoliikennerajapinnat yleisesti käytettyjen standardien mukaan
V2G
• Tekninen demo
• Modifioitu Plug-in hybridi (Prius)
• Ei standardi rapapintoja, kommunikaation rauta (auto - tolppa)
noudattaa jokseenkin uuden päivittyvän latausstandardin mukaista
rakennetta
20
Jukka Lassila, LUT 10.3.2015
LUT GREEN CAMPUS DEMONSTRATIONS
Frequency control, controllable charging
Hz
z
GC
EMS
Ethernet
GC
unit,
Linux
Lataustolppa
Sähköverkko
Electricity utility
Ensto, RS485
Data
21
Jukka Lassila, LUT 10.3.2015
LUT GREEN CAMPUS DEMONSTRATIONS
Frequency control, V2G
Teho (W)
2500
2000
1500
1000
500
0
11:40
11:45
11:50
11:55
12:00
12:05
12:10
12:15
12:20
12:25
12:10
12:15
12:20
12:25
Aika
Taajuus (Hz)
50.05
50
49.95
49.9
11:40
11:45
11:50
11:55
12:00
12:05
Aika
22
Jukka Lassila, LUT 10.3.2015