CEESA PROJECT
WP 3. FUTURE ELECTRIC POWER SYSTEMS
Birgitte Bak-Jensen
Poul Alberg Østergaard
Jayakrishnan R. Pillai
Kai Heussen
Morten Lind
Jacob Østergaard
Aalborg University (AAU)
Aalborg University (AAU)
PhD. student (AAU)
Ph. Student (DTU Elektro)
DTU
DTU
2
OUTLINE OF PRESENTATION
∙
The CEESA project
∙
Background
∙
Objective of Work package: Future Electric Power Systems
∙
Energy storages
∙
Vehicle-to-grid (V2G) power
∙
Future Power System Control Architecture
The CEESA project
3
CEESA
(Coherent Energy and Environmental System Analysis)
∙ Overall idea of the project:
▫ Concerns three major challenges of future
sustainable energy system.
◦ Integration of the transport sector
◦ Development of future power system, suitable for the
integration of distributed renewable energy sources
◦ Development of public regulation in an international
market.
The CEESA project
4
∙ For a range of scenarios the work will be carried out
in four transversal themes and then gathered for
developing tools and methodologies for a new
generation of coherent energy and environmental
analysis.
5
BACKGROUND
∙
30% renewable energy by 2025 in Denmark
▫
▫
▫
50% electricity consumption from wind power.
Double the present wind power capacity.
Reduce the use of fossil fuels by 15% from the current level
(Danish Energy Authority, 2007 )
∙
Expected electricity consumption in 2025 – 38TWh
(2005 – 35TWh)
∙
Estimated electricity generation capacity in 2025 – 12,900MW
▫
▫
▫
Wind power – 6,500MW
Central power stations – 4,100MW
Local CHP – 2,300MW
(Energinet.dk, 2007)
6
HIGH PENETRATION OF RENEWABLES MAJOR CHALLENGE
∙ Balancing the electricity system
▫ Wind energy is produced, when wind blows, not when power is demanded.
▫ At 10% wind penetration, increase in reserves are 2-4% of the installed wind
power capacity.
◦ Extra system costs of €2-4/MWh
(EU, 2005)
▫ In Denmark, for 20% wind penetration, increased reserve requirements of 5%
of the wind capacity.
(Holttinen, 2005)
▫ Realised by central and local power plants in Denmark and abroad.
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BALANCING SOLUTIONS
∙
New Network Interconnections
▫
Great belt Link 1 (600MW, 2010), Great belt Link 2 (600MW, 2018), Germany - West
Denmark (2500MW, 2025), Norway - West Denmark (1600MW, 2013)
(Energinet.dk, 2007)
∙
Regulation of wind power production (Grid codes)
∙
Energy Management
▫
▫
Demand response
Heat pumps and electric boliers
∙
Energy Storages
∙
Electric Vehicles
WP3. Future Electric Power systems
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Traditional Power Systems have a hierachical
vertical control and operation:
INFORMATION
FLOW
ENERGY FLOW
GENERATORS
TRANSMISSION
POWER SYSTEMS
DISTRIBUTION
POWER SYSTEMS
COSTUMERS
WP3. Future Electric Power systems
9
∙
Future Power Systems will have a horizontal control and
operation because of the Distributed Generation (DG) and the
integration at Distribution level:
INFORMATION
FLOW
ENERGY FLOW
GENERATORS
TRANSMISSION
POWER SYSTEMS
DISTRIBUTION
POWER SYSTEMS
DG
COSTUMERS
∙
∙
∙
∙
DG integration affects the network technically in a number of
different ways and Distribution Network Operators (DNO) must
keep high system availability and power quality.
Radical shift in the philosophy of operation and development of
distribution networks: from traditionally passive to active
systems.
DNO must develop new strategies for both grid operation and
control.
Can energy-storages be helpful considering feeding electrical
vehicles or other kind of transportation from the distribution
network.
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OBJECTIVE
To investigate and evaluate the use of energy storage
systems and electric vehicles to optimize the performance of
future electric power systems dominated by renewable
energy generators and find the associated control strategy
for this system.
WP3. Future Electric Power systems
11
∙ Problems to be dealt with:
∙ Static and Dynamic simulations of the new power
systems structure.
▫ Model of network grid with special focus on the distribution
network for static load flow simulations
◦ Power generation units
◦ Existing (Central power plants, CHP, Wind Turbines)
◦ Future (solar systems, micro turbines, small units at individual customers)
◦ Etc
◦ Loads
◦ Linear and non-linear
◦ Different load categories (City, rural, industry etc.)
◦ Special loads
 Units for supplying vehicles
 Units for generation of hydrogen
◦ Transmission lines (meshed or radial)
◦ Transformers
◦ Energy storages
◦ Etc.
WP3. Future Electric Power systems
12
∙ Static and Dynamic simulations of the new power
systems structure continued.
▫ Dynamic model of the network grid, model include all the above
units together with:
◦ Protection system components
◦ Relays, switches, fuses etc.
◦ Control systems including custom power systems for voltage and reactive power
control
∙ Evaluation, analysis and the selection of future
control strategies for different structures.
▫ Development of an active control structure at the distribution level
▫ Analysis of new trends for control
ENERGY STORAGES
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ENERGY STORAGES
Source: Energy storage.org
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ENERGY STORAGES - DENMARK
∙ Pumped Hydro Storage
▫ Hydro reservoirs in Sweden and Norway (”Virtual storage”)
∙ Compressed Air Energy Storage
▫ Optimal CAES supports 55% wind integration
(G.Salgi and H.Lund, 2008)
∙ Flow batteries
▫ Vanadium Redox batteries (Renewable support)
∙ Batteries
▫ Lead acid (kW applications)
▫ NiMH, Li-Ion (electric vehicles)
(Danish Energy Authority, 2004)
VEHICLE-TO-GRID (V2G)
17
VEHICLE TO GRID (V2G) POWER
Source: Kempton, 2005
∙
On an average, cars are parked 23 hours a
day.
∙
If 13% of 2 million cars, converted to
electric, the energy stored in vehicles can
supply the average electricity demand in
Denmark.
(Kempton, 2006)
∙
Plug in at home, office parking lots.
∙
Bidirectional power transfer.
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V2G POWER
Source: Tomic, 2005
∙
Vehicles can store energy during
low demand period and supply
when power is required.
∙
Vehicles
can
act
as
a
controllable load to buffer
variable renewable energy and
power system peaks.
∙
Grid operator could use the
energy stored in the plugged-in
vehicles for power balance.
∙
Vehicle owners will be payed for
the power balancing services.
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V2G VEHICLES
∙ Battery electric vehicles
∙ Plug-in hybrid
vehicles
electric
∙ Fuel cell electric vehicles
Source: Kempton, 2005
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V2G APPLICATIONS – POWER SYSTEMS
∙ Peak load power
▫
Periods of
hours a day
higher power requirement, 4-6
∙ Spinning reserve
▫
▫
▫
Extra online generation
To meet system failures (Loss of Transmission
line, Generator etc.)
20 times a year, 10 min – 1 hour duration
∙ Regulation
Source: Letendre, 2007
▫
▫
Online generation to ensure steady system
voltage and frequency
400 times a day, few minutes duration
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OBSERVATIONS
Renewable
type
Renewable
application
Capacity
(GW)
Support
type
V2G support
V2G
availability
Current fleet %,
V2G type
Solar PV
Peak load
(10%)
1.3
Dedicated
storage (1 hour)
1.3GW
50%
9% battery
Wind
Base load
(50%)
9.3
Regulation
558MW
50%
4% battery
Spinning reserve
(3 hours)
930MW
50%
6% fuel cell, or
7% battery, or
33% hybrid
∙
Battery electric vehicles are ideal for regulating power applications.
∙
Fuel cell electric vehicles has better power handling capability for spinning reserve applications.
∙
Power limited by the line capacity (15-20kW).
∙
With rapid development of high storage capacity batteries and fuel cells technology, less number of
electric vehicles can realise the above scenario.
∙
Social synergy between electric vehicles and renewable energy in ensuring CO2 - free electricity and
transportation.
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WORK PLAN – WP 3.1
∙ Modelling of aggregate and distributed configurations of
energy storages, V2G systems and renewables.
∙ Load flow analysis of future Danish electric networks to verify
electric power balance.
∙ Stability and short circuit studies.
∙ Technoeconomic analysis of storage/V2G supported future
electric power systems.
FUTURE POWER SYSTEM
CONTROL ARCHITECTURE
What is ”Power System Control Architecture" ?
24
The classic picture
∙ Active (control)
▫ Transmission connected: Generation
P
▫ Control of
 Frequency (ubiquitous)
f
Transmission Voltage V Q
∙ Passive (no control)
▫ Distribution Systems – Load
Predictable daily / seasonal variation
ØrstedDTU
Centre for Electric Technology
V
V
V
What is ”Power System Control Architecture" ?
25
The classic picture + some Wind (DER)
∙ Active (control)
▫ Transmission connected: Generation
P
▫ Control of
 Frequency (ubiquitous)
f
Q
Transmission Voltage V
∙ Passive (no control)
▫ Distribution Systems – Load
Predictable daily / seasonal variation
▫ Distributed Generation
”negative load”
ØrstedDTU
Centre for Electric Technology
V
V
V
What is ”Power System Control Architecture" ?
26
Storage
V
V
V
V
Control?
CHP
Micro CHP
ØrstedDTU
Centre for Electric Technology
The Challenge to Control Architecture
27
∙ The classic architecture
is challenged by
distributed input
 understand of how to
integrate DER into PS
control
 Future ”active”
Distribution Systems
ØrstedDTU
Centre for Electric Technology
Trends in Power System Control
28
More Challenges …
∙ Less Inertia ?
∙ More stochastic
influence
▫
▫
∙
∙
∙
Uncontrollable inputs
Unobserved power
flows
Evaluate ”efficiency”
of Solutions
”Storage” integration
Ownership and
regulation issues
 Who may control
what?
New Technologies
∙ Virtual Power Plant
(VPP)
▫
∙
Centre for Electric Technology
Technical Full-Control
Solution
Demand Control
▫
Dispatchable load, DFR,
…
∙
Centralization:
∙
Decentralization:
somes unsolved questions!
ØrstedDTU
Microgrids, Cells
▫
∙
Commercial integration of
DER
▫
unit intelligence, (power
electronics), more
inputs…