RWE Deutschland 23.05.2016 SEITE 1
successful integration of distributed
generation in rural areas
Sven Jundel
Manager New Technologies
RWE Deutschland AG
RWE Deutschland 23.05.2016 PAGE 2
The Project: Grids for Future Electricity Suppy
Project Consortium
Project Leader RWE Deutschland AG
Timeline July 2009 – Sept. 2011 Carried out by the consortium
Oct. 2011 – Dec. 2016 Verification phase by RWE
> Identification of efficient distribution grid concepts
> Further development of evaluation methods
> Further development of equipment
> Realisation of a large-scale field demonstration
Objective
RWE Deutschland 23.05.2016 PAGE 3
Decentralised renewable generation exceeds demand;
3.900 km² in the southwest of Germany are analysed
526
848
1.010
551
292
13235
+271%
1.541
+53%
+124%
Sum Wind PV Biogas
MW
3.800
Water
1.200
1.000
800
600
1.400
200
0
450
3.747
400
2012
2010
2005
original grid design of
Sum
2030
Intelligent distribution grid design is necessary
20
05
20
10
20
12
medium and low voltage level
min
. Scenario
max. S
cen
ario
min. Scenario: with reference to Ministry of Environment (Lead Study 2011)
max. Scenario: with reference to grid development plan 2012 of the Federal Network Agency (Bundesnetzagentur)
Installed capacity end of year
RWE Deutschland 23.05.2016 PAGE 4
Test grid area covers a hot spot of renewable
generation in the analysed region (3.900 km²)
Kyll
Kyll
Mo
sel
Mosel
64
1
1
1
60
60
602
Trier
Bernkastel-Wittlich
Eifelkreis Bitburg-Prüm
Trier-Saarburg
Municipalities in the test grid area:
17,019 Inhabitants
343 km² Covered area
Customers directly connected
to innovative equipment:
5,340 Inhabitants
178 km² Covered area
1,400 Service connections
50.0 MW Renewable generation
3.0 MW Max. load p. a.
74 Secondary Substations
16 times higer generation than
max. annual load
RWE Deutschland 23.05.2016 PAGE 5
Different innovative solutions are realised
in the test grid area – sorted into 4 groups
Use of information- and communication technology (ICT) 1
3
2 Disposition of storage devices
Local voltage control to exploit grid transportation capacity
RWE Deutschland 23.05.2016 PAGE 6
Tested solutions for distribution grids
Use of information- and communication technology (ICT) 1
ICT to reconstitute grid observability in medium voltage
Wide area control
RWE Deutschland 23.05.2016 PAGE 7
Reconstitution of grid observability is accessible
through a few specific measuring points
Primary 20-kV-substation
Secondary substation
with PV-feed-in
20-kV-overhead line
20-kV-cable
Open sectioning point
Measuring point
Active
po
we
r [k
W]
Power distribution Power collection
BioCHP
Windpower
Windpower
Windpower
BioCHP
RWE Deutschland 23.05.2016 PAGE 8
Wide area control:
Reduces grid expansion by optimised voltage control
medium
voltage
G
G
G
G
G
f(x)
G
Communication link
Voltage measurements at extreme points in secondary substations
110 kV 110 kV
Control system
Goal: Optimising the voltage control of the 110-kV-Transformer by using voltage
measurements from extreme points of the medium voltage grid
Control principle:
> Status 0 (reference value):
normal load and feed-ins
> Status 1 (reduced reference value):
low load and high feed-ins
> Status 2 (increased reference value):
high load and low feed-ins
Basic design of a wide area control system:
RWE Deutschland 23.05.2016 PAGE 9
Function Principle of Wide Area Control
K012
K008
K006
K007 K004
K013 K015
K011 K014
K012
K008
K006 K007
K004
K013
K015
K011
K014
Step 3: +4% (9,6 : 0,4 kV)
Step 3: +4% (9,6 : 0,4 kV)
Step 1: -4% (10,4 : 0,4 kV)
Step 1: -4% (10,4 : 0,4 kV)
K012
K008
K006 K007
K004
K013
K015
K011
K014
98 %
99 %
100 %
101 %
102 %
103 %
104 %
105 %
106 %
107 %
108 %
109 %
110 %
0 2 4 6 8 10 12 14 16 18 Leitungslänge / km
K012
K008
K006
K007 K004
K013 K015
K011 K014
RWE Deutschland 23.05.2016 PAGE 10
Wide area control: Design of the measuring systems
RWE Deutschland 23.05.2016 PAGE 11
Results of wide area control:
Voltage fluctuations are reduced by 30 %
380367350
334
428419
260268253283285
258
0
50
100
150
200
250
300
350
400
450
Circuit
E
Circuit
D
Circuit
C
Circuit
B
Circuit
A
Average
voltage
fluctuations
38% 33% 15% 28% 27% 29%
Voltage fluctuations [V]
Ø
Voltage control with wide area control assistance
Voltage control without wide area control assistance
RWE Deutschland 23.05.2016 PAGE 12
Tested solutions for distribution grids
2 Disposition of storage devices
Biogas storage in coordination with fluctuating energy
resources works as a storage for all kinds of renewables
RWE Deutschland 23.05.2016 PAGE 13
Biogas storage in coordination with PV-generation
works similar to a battery
Medium Voltage
3 ~
Digester
Biogas
Storage
3 ~
PV
AC
DC
Stored biogas
(0 – 1.600 m³)
Substrate (liquid)
Weather membrane
Belt
system
Air
Cushion gas
Moving
membrane
Heater
Stirring
unit M
RWE Deutschland 23.05.2016 PAGE 14
Biogas storage in coordination with PV-generation
Biogas storage
3.2 MWhel
220-kVA-CHP
0
10
20
30
40
50
60
70
80
90
100
0
50
100
150
200
250
300
350
400
450 0
:00
3:0
0
6:0
0
9:0
0
12
:00
15
:00
18
:00
21
:00
0:0
0
PV
-fe
ed
-in
[%
]
CH
P p
ow
er
[kW
]
CHP power PV power
RWE Deutschland 23.05.2016 PAGE 15
Tested solutions for distribution grids
3 Local voltage control to exploit grid transportation capacity
Electronic voltage regulator in medium voltage level
Voltage regulated secondary substation
RWE Deutschland 23.05.2016 PAGE 16
Local voltage control to exploit grid capacity:
8-MVA-regulator serial in 20-kV-overhead-line
Grid
Load
S=8 MVA
P=7.2 MW
Q=3.5 Mvar
cosφ=0.9
AC / DC /AC
P=7.4 MW
Q=3.2 Mvar
P=0.7 MW
Q=0.3 Mvar
P=6.5 MW
Q=3.2 Mvar
P=0.9 MW
Q=0.0 Mvar
ΔU = 20%
SVoltage-Regulation=0.8 MVA
(approx. 10% of the power flow)
RWE Deutschland 23.05.2016 PAGE 17
In operation: 30 days with constant output voltage
Output voltage
Input voltage
Time
Voltage
RWE Deutschland 23.05.2016 PAGE 18
Thank you for your attention and greetings from
„Smart Country“
Windpower
PV generation
Biogas
generation
Biogas
storage
… because the energy transition
is taking place in the countryside
RWE Deutschland 23.05.2016 PAGE 19
Backup
RWE Deutschland 23.05.2016 PAGE 20
Inhomogeniety of energy supply-task drives grid-costs
Source: Google
Urban area
Rural area
with supply
Rural area
without supply
Load per area:
Generation per area:
Wind power
Photovoltaics
Hydro power
Biomass energy
A Rural Administrative District in Germany
1 km²
RWE Deutschland 23.05.2016 PAGE 21
Energy Supply-Task Description of all 402
Administrative Districts in Germany
P1 P2 … P45
LK 1 1,0 1,2 … 50,1
… … … … …
LK 413 1,4 1,8 … 48,2
2035
P1 P2 … P45
LK 1 1,0 1,2 … 50,1
… … … … …
LK 413 1,4 1,8 … 48,2
2030
P1 P2 … P45
LK 1 1,0 1,2 … 50,1
… … … … …
LK 413 1,4 1,8 … 48,2
2025
P1 P2 … P45
LK 1 1,0 1,2 … 50,1
… … … … …
LK 413 1,4 1,8 … 48,2
2020
P1 P2 … P60
LK 1 1,0 1,2 … 50,1
… … … … …
LK 413 1,4 1,8 … 48,2
402
Administrative
Districts in
Germany
60 Parameters describe the Energy Supply-Tasks
5 Steps of Analysis
2015
RWE Deutschland 23.05.2016 PAGE 22
Installations inside the Biogas Storage Reservoir
The biogas storage covers
a digestate storage
RWE Deutschland 23.05.2016 PAGE 23
400-kVA-substation with flexible added
active voltage regulation at low voltage level
20 kV 0.4 kV
Voltage control
~ =
= ~
Transformation
PCS 100 AVC Product Design
> +/-10% Continuous Regulation
> Pilot Project: 400 kVA AVC 400 V
RWE Deutschland 23.05.2016 PAGE 24
Tested solutions for distribution grids
4 Hierachical supply layers in medium voltage level
Strong cable line with electronic sectionalizers
RWE Deutschland 23.05.2016 PAGE 25
Strong cable line with electronic sectionalizers
Grid expansion for DER (cabel)
Circuit breaker
Sectionalizer
Open section point
Existing grid (overhead line)