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06‐11‐20122
Presentation Outline
• Power System Structure
• Danish Power Systems
• Distribution Grids and Models
• Future grid challenges & trends
3 06‐11‐20123
Power System Structure
Source: JRC-EU, 2007
4 06‐11‐20124
Danish Power Systems
Source: K. Behnke, Energinet.dk, 2010
5 06‐11‐20125
Wind Power (2011) - Denmark
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40
60
80
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1 1001 2001 3001 4001 5001 6001 7001 8001
% W
ind
pow
er b
ased
on
load
dem
and
Hours
Average electricity supplied by wind power (2011): 29%
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Power Fluctuations – Horns Rev
Source: DONG Energy, 2010
06‐11‐20127
Frequency Reserves – West Denmark
Source: ENTSOE, 2012
06‐11‐20128
• Estimated electricity generation capacity in Denmark by 2025– Wind power – 6,500MW (3200MW - 2007)– Central power stations – 4,100MW (7200MW - 2007)– Local CHP – 2,300MW
Future Offshore Wind - 2025
06‐11‐20129
• Generation– Regulation of wind power production (Technical Regulation 3. 2. 5 ), Geographical
spread of Offshore Wind farms
• Transmission– New Grid Interconnections : Great Belt Link 2 (600MW, 2018), Germany
- West Denmark (2500MW, 2017), Norway - West Denmark (700MW,2014), Holland - West Denmark (700MW), Reinforcement andexpansion of existing grid. (Energinet.dk, 2010)
• Distribution & Consumption Side– Heat Pumps, Electric Boilers, Electric Vehicles– Demand Side Management & Demand Response– Smart Grids
Future Power Balancing Solutions
10 06‐11‐201210
Aggregated Grid Models : System Balance
Source: A.Suwarnaraat, 2007
11 06‐11‐201211
Grid Balancing Models
Source: A. Suwarnaraat, 2007
12 06‐11‐201212
Power Distribution System – WP2
Source: P.Chen & P.Mahat 2011
13 06‐11‐201213
LV Grids - Brønderslev
(LV‐III)
(LV‐I)
(LV‐II)
Source: Google Maps
14 06‐11‐201214
Particulars - LV Grids
Each Household is connected through a 35A fuse to the cable boxes,distributed across different feeders
LV Grid Transformer No. of feeders
House-holds
Annualconsumption
Household(highest
consumption)
Average annual
demand
LV – I 10/0.4 kV, 400 kVA
8 84 330,041 kWh 13,450kWh 3,929kWh
LV – II 10/0.4 kV,630 kVA
6 166 738,345 kWh 15,615kWh 4,395kWh
LV – III 10/0.4 kV, 400 kVA
5 75 325,526 kWh 10,997kWh 4,340kWh
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LV-I Grid Model
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LV-II Grid Model
06‐11‐201217
LV-III Grid Model
06‐11‐201218
LV-II Grid : Even distribution of EVs
Daily Load curve
EVs distributed per feeders
Transformer max. capacity
EVs typically not parked at home during day time
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EV Integration Summary
LV-1 LV-II LV-III
Min. demand Max. Demand Min. Demand Max. Demand Min. Demand Max. Demand
Feeders No of EVs
Voltage (pu)
No of EVs
Voltage (pu)
No of EVs
Voltage (pu)
No of EVs
Voltage (pu)
No of EVs
Voltage (pu)
No of EVs
Voltage (pu)
1 5 0.96 5 0.96 2 0.95 1 0.94 7 0.94 5 0.94
2 4 0.96 4 0.96 3 0.94 0 0.94 13 0.95 11 0.94
3 2 0.98 2 0.98 9 0.95 5 0.95 1 0.99 1 0.99
4 7 0.94 6 0.94 8 0.96 4 0.94 2 0.94 0 0.94
5 4 0.98 3 0.98 3 0.94 0 0.94 3 0.98 3 0.98
6 5 0.98 3 0.98 3 0.94 0 0.94 - - - -
7 3 0.94 2 0.97 - - - - - - - -
8 4 0.94 2 0.97 - - - - - - - -
• EV penetration of LV-III grid are limited by under-voltage limits, where halfof the LV-II grid feeders (F2, F5, F6) and one of the feeders (F4) of LV-IIIgrid do not have a single EV charged during peak demand period
06‐11‐201220
EV Integration Summary
Transformer loading
Active power losses (%)
Min. demand
Max. demand
LV-I 100% 3.62 3.58
LV-II 56% 2.91 2.71
LV-III 80% 3.92 3.75
Min. demand Max. demand
Cables Loading Cables Loading
LV-I
C1 37% C13 43%
C13 36% C1 42%
C31 31% C5 27%
LV-II
C21 55% C21 40%
C30 49% C44 39%
C39 38% C30 36%
LV-III
C7 85% C7 81%
C1 50% C1 47%
C19 44% C28 40%
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5
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25
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35
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45
LV-1 LV-II LV-III
EV
pen
etra
tion
(%)
Minimum demandMaximum demand
• The grid LV-I has the highest capability of incorporating EVs (40% and 32%)than LV-III (35% and 27%) followed by LV-II (17% and 6%).
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Grid Reconfiguration : LV-II Grid
• Simple and cheap possibilities of grid reconfiguration (closing ”open tie” pointsacross various feeders)
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Grid Reinforcement : LV-II Grid
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Grid Reinforcement : 3349 ThorshøjFeeders
Min. Demand Max. Demand
No of EVs Voltage (pu) No of EVs Voltage (pu)
1 2 0.94 1 0.94
2 4 0.94 1 0.94
3 11 0.95 6 0.954 8 0.94 5 0.94
5 7 0.94 3 0.94
6 7 0.94 4 0.94
EV penetration (%) 23% 12%
Transformer loading 75%
Cable loading C21,C1,C39 C21,C39,C57
Active power losses 3.70%
• It is able to charge 6% additional EVs in the LV-II grid, each during theminimum and maximum demand hours.
• The feeders which could not even incorporate a single EV as in the basecase, were able to add a few number of them.
• The transformer capacity utilisation has also increased from 56% (basecase) to 75% by adopting simple grid reinforcement measure.
24 06‐11‐201224
Feeder Reinforcement : LV-III Grid
Cable box 21 splitted into two
New feeder
25 06‐11‐201225
EV charging mode EV discharging mode
Before splitting Feeder F4Cables Households EVs per
feederEV
penetration
Feeders F1, F3 & F5 19 11 58%
Feeder F2 22 13 59%Feeder F4 34 4 12%Total 75 28 37%
After splitting Feeder F4Feeders F1, F3, F5 19 7 37%
Feeder F2 22 9 41%Feeder F4 18 7 39%
Feeder F4X 16 6 38%Total 75 29 39%
Before splitting Feeder F4Cables Households EVs per
feederEV
penetration
Feeders F1, F3 & F5 19 15 79%
Feeder F2 22 17 77%Feeder F4 34 8 24%Total 75 40 53%
After splitting Feeder F4Feeders F1, F3,
F519 10 53%
Feeder F2 22 12 55%Feeder F4 18 10 56%
Feeder F4X 16 8 50% Total 75 40 53%
Feeder Reinforcement : LV-III Grid
• After splitting feeder F4 into two (F4 & F4X), more EVs can beaccommodated in F4 & F4X, also equal EV penetration (%) on all feeders.
26 06‐11‐201226
Primary grid impacts with EVs, HPs ..Lines
overloadedTransformer overloaded
Voltage drops
27 06‐11‐201227
Overview : Grid bottlenecks
Source: SEAS-NVE 2012
28 06‐11‐201228
Future Operation Scenario
• How Distribution System Operator (DSO) could predict& prevent these grid congestions?o Grid reinforcement (bigger cables, spitting feeders etc.)o Demand Forecastingo Pre-emptive control of local generation and demand units
• How DSO could monitor these grid congestions?o Grid monitoring deviceso Aggregation of Smart Meters
• How the DSO could solve these issues?o Investments for grid expansiono Demand Side Management, real time communication and
control of generation or demand (local household controllers)
29 06‐11‐201229
Trends : Future Smart Grid
• Today - Smart Meteringo Metering and billing, power quality monitor outages and
events, little consumer participation
• Tomorrow - Grid Optimisationo Asset monitoring and management (Transformer, LV
nodes/feeders), alarms, automation of LV controls,customer interaction through portals, flexible pricing
• Future - Proactive Grid Managemento predictive and adaptive grid protection/control, intelligent
distribution management systems, active ‘prosumers’participating in electricity market
Thank you for your attention!
