1.
Dynamic Line Rating
Principles - Applications -
Benefits
Jean-Louis Repetto & Rena Kuwahata (Ampacimon)
July 2019

2.
ISGAN in a Nutshell
Created under the auspices of:
the Implementing
Agreement for a
Co-operative
Programme on Smart
Grids
1/8/2018 ISGAN STANDARD PRESENTATION 2
Strategic platform to support high-level government
knowledge transfer and action for the accelerated
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Studies
Annex 3
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and
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Annex 4
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of Insights
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Makers
Annex 5
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al
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Annex 6
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Annex 8:
ISGAN
Academy
on Smart
Grids

3.
ISGAN’s worldwide presence
1/8/2018 ISGAN STANDARD PRESENTATION 3
3

4.
Value proposition
4
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presentations
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briefs Technology
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1/8/2018 ISGAN STANDARD PRESENTATION 4

5.
Presentation Overview
5
Physics of DLR
What is DLR and how does it
work?
01
Applications
How is DLR used by grid operators?
02
Benefits
Use cases and analytics
03
Wrap up / take away
04

6.
Physics of DLR
What is DLR and how does it work?
6

7.
Clearance
Sag
Suspension
Section
Span
Dead-end
Earth wire
Dead-end
Clearance
Line capacity is limited by sag and
conductor temperature
• Thermal limits
• Maximum Conductor Temperature
• Maximum Sag
• Rating (maximum load current)
• Static based on fixed/seasonal, conservative
ambient conditions, no field information
• Dynamic based on variable, real-time ambient
conditions, with field information
Physics of DLR
7

8.
Line capacity is sensitive to weather
Ambient conditions impacting rating:
• Wind speed
• Temperature
• Solar irradiation
Physics of DLR
8

9.
Applicable standards and guidelines for
calculation of line ratings
9
Calculation methods are based on Cigré and IEEE
IEEE 738
Cigré TB 207
Cigré TB 601
Cigré TB 498
https://e-cigre.org/
https://ieeexplore.ieee.org/
Physics of DLR

10.
Closer look at critical parameters
affecting ampacity
Physical
• Clearance
• Conductor temperature
• Transmission line properties
Electrical
• Line current (for some applications)
Ambiental
• Effective perpendicular wind speed
• Ambient temperature
• Solar irradiation
IEEE
738
CIGRE
TB207
Critical parameters
Ampacity
Physics of DLR
10

11.
Approaches to monitoring critical
parameters
Technologies
11

12.
Sensor-based monitoring
12
How critical parameters are obtained
Line-mountedsagsensor
• Direct measurement
of:
• Sag
• Effective
perpendicular wind
speed
• Ambient temperature
• Vibration (e.g.
galloping)
• Infers:
• Conductor
temperature
• Clearance
• Third-party inputs:
• Ambient temperature
• Solar irradiation
• Line current
Line-mountedclearancesensor
• Direct measurement
of:
• Clearance
• Inclination
• Vibration
• Infers:
• Sag
• Conductor
temperature
• Third-party inputs:
• Wind speed
• Ambient temperature
• Solar irradiation
• Line current
Line-mountedconductor
temperaturesensor
• Direct measurement
of:
• Discrete point
conductor
temperature
• Inclination
• Ambient temperature
• Infers:
• Sag
• Clearance
• Third-party inputs:
• Wind speed
• Solar irradiation
• Line current
Indirectsensor
• Infers:
• Current from
electromagnetic field
• Sag/Clearance from
optical information
• Effective wind speed
from remote weather
stations
• Calculates based on
spec-sheet values and
theoretical model of
transmission line:
• Conductor
temperature
• Sag/Clearance
Technologies

13.
Installati
on
design
studies
Installatio
n process
Sensor
calibratio
n
Power
source
Min,
operating
current
Wind
speed
Conduct
or
temperat
ure
Conduct
or sag /
clearanc
e
Line
operation
al safety
Processin
g power
DLR
Accuracy
Line mounted
sag sensor
Line mounted
conductor
temp. sensor
n.a. ?
Pole-
mounted
weather
station
?
Weather
model
Poor [-]Excellent [+]
Features Comparison
Technologies
13

14.
On what kind of assets can DLR be used?
• Dynamic “Line” Rating applies to Overhead and Underground circuits (techniques differ)
• Dynamic rating exists also for power transformers
• What kind of overhead lines?
• Voltage levels up to 800kV
• Sensor installation with or without shutdown
• DC cannot do because sensors are powered by induction
• Compatible with HTLS
• Alloy type is not important (ACSR to copper)
• Conductor diameter, bundles are mere parameters
• Max. conductor temperature vs. ambient temp (40C)
• It can be used on lines with spacers and dampers
• Line length unimportant (we have examples from 2km to 100km)
1/8/2018 ISGAN STANDARD PRESENTATION 14

15.
Applications
Examples of implementation by grid operators
15

16.
Real-time
Grid Operation Activities
Grid operator’s activities
• Ensure security of grid at all times
• Design and secure sufficient grid capacity for reliability
• Lean design and maximize utilization for affordability
16

17.
Drivers and values
1/8/2018 ISGAN STANDARD PRESENTATION 17
Challenges faced by grid operators where DLR brings value
Decarbonization
Decentralization
Digitalization
Regulation
Climate Change
Avoided reinforcement cost
Delayed reinforcement costs
Avoided congestion management costs (counter-
trading, redispatch, curtailment of RE, load shedding)
Increased trade capacity (access to energy in cheaper
price zones)
Increased social welfare from access to cheaper
energy (from neighbor and less sub-optimal dispatch
caused by congestion)
Increased visibility on asset performance and risks
Value
of
Grid Capacity
&
Monitoring

18.
Bottlenecks to implementation/operation
Incentive not set
by regulator
CAPEX based
incentives, no OPEX
saving rewarded
Perverse incentives to
overinvest
Incentivize TOTEX
optimization!
Costs and benefits may
be in different time
horizons (diff.
regulatory cycles)
State-derived,
conservative,
hierarchy
customer
organizations
Requires cross-
departmental
coordination
Decision making slow
Reward innovation!
Promote competition!
National emergency!
Even then it takes time,
so start early!
Grid security
assessment and
hosting capacity
rule (N-1)
Can the Operator
change operating limits
of Asset Owner’s
equipment?
Can the Operator
control the Generator
output in case it causes
overloading according
to DLR?
Make responsibilities
and control capability
clear between
Operator, Asset Owner
and Generator
What options do
Grid Operators
have to meet
responsibility?
Does Operator have
capability to monitor
and control?
e.g., SCADA, EMS,
remote control of
switches?
Which asset is actually
causing the bottleneck
in grid capacity?
Adopt modern
technology and training
that allows fast and
remote control!
Understand your asset!
1/8/2018 ISGAN STANDARD PRESENTATION 18

19.
Synergies with additional benefits
Asset risks can be better monitored
• Temperature, Sag
• Vibration sensors detect also physical anomalies (tower fall, galloping, icing)
Maintenance outage can be better managed
• Check if DLR gain is sufficient to manage the typical congestion caused by outage or additional measures will
still be required
Improvement on maintenance by better load monitoring
• Accurate assessment of loading characteristics in relation to aging
DLR does not detect fault currents, but helps in emergency situations
• But it helps with increased loading due to power re-routing caused by fault/damage induced outage
Active network management
• Automated relays could be linked with DLR
1/8/2018 ISGAN STANDARD PRESENTATION 19

20.
Security (N-1) calculations use DLR values
Real-time
Grid Operation Activities
DLR data input
Improved
outcome
Reduce human error by
integration of data to existing
tools and processes
Avoid costly remedial actions
Reduce need for
cumbersome switching
actions
Ensure minimum clearance
at all times
Typical
benefit
20

21.
Congestion management options
(best practice remedial actions)
Own illustration based on information from: ENTSOE Operational Handbook, used as basis for grid
operation guidelines by each European TSO. Actual applied process may vary from TSO to TSO. 21

22.
Example from Belgium
Intraday operation on 14/09/2017
• High N-> S flows + 380.74 in outage
• D-1 : PSTs = 6/6/6/6 + 150kV topological measures (still problematic, redispatching prepared)
• RT: PSTs = 4/4/4/4, 380.73 highly loaded, no topological measures left, DLR avoid redispatching
https://www.entsoe.eu/events/2019/03/20/smart-grid-world-of-innovations-dynamic-line-rating-webinar/
Outage: load shift starts
Capacity steep increase - due to wind
Rating capped (TSO rules)
Redispatching avoided
22

23.
Example from Belgium: display of real-
time data
23
EMS (RT tool) used in the National Control Centre
• Adaptability to
generally used
monitoring
systems
• No change to
existing
monitoring
systems
required!
https://www.entsoe.eu/events/2019/03/20/smart-grid-world-of-innovations-dynamic-line-rating-webinar/

24.
Forecast ratings are needed for grid
operation (video clip)NOTEmistakeinvideo:Vertical
axisshouldread“lineratingin
amps”not“windspeed”
24

25.
Benefits
Use cases and analytics
25

26.
Belgium benefits from reliable capacity increase
for congestion relief in intraday and day ahead
1/8/2018 ISGAN STANDARD PRESENTATION 26
• DLR maximize import capacity on all
critical cross-border lines.
• Critical internal lines are also equipped
with DLR sensors.
• Two days ahead capacity forecast offers
additional exchange volume to the market.
Example: 19/2/2015
• Market limited by Belgian lines.
• By using 2-day ahead forecast, less constrained.
3% gain on limiting lines released 22% gain on x-
border exchange.
• Result: in 4 hours, the gain on the CWE welfare
computed to 247 250 € (Elia)
Key reference 1

27.
Belgian Offshore Wind Connection
 Belgian offshore wind installations
concentrated in one location.
 Began installation in 2009.
 Infeed data available on Elia
website.
 2 onshore connections.
 When offshore wind installations
began in 2009 and until 2017 only
150kV network existed
 “Stevin” 380 kV link commissioned
end of 2017 to alleviate the sub-
transmission network.
 DLR sensors installed to monitor
the high loads since 2014.
SL
ZB
BR
Stevin 380kV
150kV Line
150kV Line
150kV Line
Offshore Interconnector
to UK
Offshore wind
TowardsBrussels
Key reference 2
27

28.
Ampacity gain from 5 years of
observation
• Maximum gain over 200%
• DLR gain was available 98% of the time 127-130% on average
90% of the time 110-116%
95% of the time 105-115%
2% of the time nominal rating
is risky
Nominal rating
Our sensor rating
Key reference 2
28

29.
Wind integration case study using
sensor data and infeed data
29

30.
Illustrative example:
Wind installation capacity larger than connection is not
permitted
30
N-1 limit using SLR
Wind infeed for
Wind farm < connection capacity

31.
Illustrative example:
Wind installation capacity larger than connection is
permitted but infeed must be curtailed
31
N-1 limit using SLR
Wind infeed for
Wind farm > connection capacity

32.
Illustrative example:
Wind infeed increases but there is still curtailment
32
Wind infeed
increase by
“oversizing” wind
farm
N-1 limit using SLR
Wind infeed
exceeding security
limit (based on
SLR) is curtailed

33.
Illustrative example:
Wind infeed increases and curtailment is reduced
33
Wind infeed
increase by using
DLR based
security limit
N-1 limit using SLR
N-1 limit using DLR

34.
DLR facilitates wind integration
because gains are high when winds
are high
• Allowing installation capacity to exceed traditional connection capacity,
• With increasing installation capacity considered on same line, curtailment begins
when the installation capacity exceeds the thermal limit of the line.
• In general, curtailment increases but so does infeed.
• DLR facilitates wind integration by:
• increasing infeed (energy that can be accepted by grid) up to 50-70%
• reducing curtailment also up to 15% compared to SLR
• increase installation capacity up to 50% without need for curtailment at all
Wind case study results
https://watttransmission.files.wordpress.com/2019/06/wind-integration-use-case.pdf
34

35.
Congestion management in Germany
• Grid congestion management is serious
concern in Europe.
• Costs of remedial actions exceeded 1Billion
EUR in Germany alone (annual costs 2017
and 2018)*1
• Cost of congestion is approx. 100 kEUR per
hour, or 4 mEUR per day *2
• Average redispatch cost is 23kEUR/GWh *3
• Line Ville Ost is often congested: in 2017
over 390 hours congestion, causing 270
GWh redispatch
Key reference 3
*1 Per country details can be seen in ENTSO-E Bidding Zone Configuration Technical Report
*2 Based on total cost of congestion management in 2017 including the “Netzreserve” costs in addition to redispatch and curtailment (values taken from Monitoring Report of BNeztA)
*3 Redispatch cost divided by redispatch amount (values taken from Monitoring Report of BNeztA for 2017)
1/8/2018 ISGAN STANDARD PRESENTATION 35

36.
Ampacity gain from 2 years of observation
Maximum gain over 200%
DLR gain was available 99.5% of the time
Nominal rating
Our sensor rating
130% gain on
average
114% gain 90% of
time
106% gain 98% of
time
0.5% of the time
nominal rating is
risky
Key reference 3
Ambient Adjusted
Rating neglecting wind
speed
On 14th February 2017, 9hr redispatch of 200MW max was instructed.
This was 1750MWh which if avoided with DLR, saved 40kEUR for this day alone.
36

37.
Duration curve of wind speeds at
sensor location show line is not at
windy location
Wind speed is less than 2m/s on
average
Less than 3.2m/s 90% of time
vs.
Wind farms normally start operating
at 4m/s
Accurate wind measurements at low wind speeds at critical line span is important to
obtain safe and useful gains
Key reference 3
37

38.
Consideration of DLR in planning phase
leads to cost savings
Designing a new line with the assumption that it will be
equipped and operated with DLR
DLR gives accurate line rating -> specific ampacity
98% of time
Uses accurate line rating for sizing of the conductor
Conductor size impacts tower size
Cost savings on conductor, tower, foundation, civil
work, tower painting etc
Key reference 4
38

39.
ASTER 329
vs
ASTER 366
ASTER 288
vs
ASTER 366
ASTER 256
vs
ASTER 366
ASTER 228
vs
ASTER 366
DLR Gain 6% 16% 23% 34%
Savings Towers(€) 13.000 31.300 42.000 55.000
Savings paint
towers(€)
28.500
69.000 92.200 120.000
Savings conductor (€) 42.000 121.500 210.500 290.000
Savings foundations
(€)
129.750
197.250 197.250 242.250
Savings other civil
eng.(€)
15.000
36.500 48.500 63.500
Total (€) 228.000 455.500 591.500 771.000
Cost Ref line (€) 4.900.000 4.900.000 4.900.000 4.900.000
Saving (%) 4.7 % 9.3 % 12.1 % 15.7 %
0
100
200
300
400
500
600
700
800
900
ASTER
228
ASTER
256
ASTER
288
ASTER
329
Savings(k€)
Conductor type ASTER (mm²)
Financial savings- line 90 kV
Other civil works
Foundations
Conductors
Towers (+paint)
Key reference 4
39

40.
Customer Testimonial (video clip)
40

41.
PSE (PL)
Ukrenergo (UA)
JSC EMS (RS)
RTE (FR)
Stanett (NO)
EGP (BR)
DLR Tender announcements
2018
1/8/2018 ISGAN STANDARD PRESENTATION 41

42.
Take aways
DLR technologies are now well proven, sensors-based, and including
Scada/EMS integrated software to optimize grid operations
Congestion management (redispatch reduction), Interconnectors
optimization, Renewables integration are obvious use cases, with
EXTREMELY quick pay-backs
Won’t replace new/upgraded lines, but can help significantly thanks to very
quick deployments, flexibility and low investment
42

43.
Further trainings
• Basics of Dynamic Line Rating – DLR
• Course description :
http://www.wlenergy.fr/2016/12/16/dynamic-line-rating/#
• Contact info : info@wlenergy.fr /
francois.hussenot@wlenergy.fr / T +33 (0) 9 82 44 12 23
• Tutorial on Dynamic Line Rating
• @ the Wind Integration Workshop
http://windintegrationworkshop.org/ 15th October, Dublin
• Recorded ENTSOE Webinar
https://www.entsoe.eu/events/2019/03/20/smart-grid-world-
of-innovations-dynamic-line-rating-webinar/
• Belgian TSO ELIA has published an extensive
description of its experience with DLR, from 70kV to
380 kV, in particular the popular forecast options for
capacity calculations.
http://www.elia.be/en/grid-data/DLR
• You probably sometimes have questions about “how
the gains are really used/valued”: in the “documents”
section, the influence of the regulator and the “cap
vs risk” approach are explained:
http://www.elia.be/~/media/files/Elia/Grid-
data/DLR/Explanatory-note.pdf
• The Ampacimon DLR FAQ (Please contact us for your
copy)
43
Webinar and tutorials Good to read…

44.
Further readings:
1/8/2018 ISGAN STANDARD PRESENTATION 44
Contact us for a copy!
[1] ENTSO-E Ten-Year Network Development Plan (TYNDP), 2016 and 2018:
https://tyndp.entsoe.eu/2016/insight-reports/technology/
https://tyndp.entsoe.eu/Documents/TYNDP%20documents/TYNDP2018/consultation/Technical/Technologies4TS.pdf
[2] WG B2-36 CIGRE. TB498: “Guide for Application of Direct Real-Time Monitoring Systems”, June 2012.
[3] A Michiorri, H-M Nguyen, Stefano Alessandrini, J Bjørnar Bremnes, S Dierer, et al., Forecasting for dynamic line rating. Renewable and Sustainable Energy Reviews,
Elsevier, 2015, pp. 1713-1730.
[4] Working Group B2-43 CIGRE. TB601: “Guide for Thermal rating Calculations of Overhead Lines.”, December 2014.
[5] Guha Thakurta, P., Nguyen, H.-M., and al. (2013). Final report on NETFLEX Demo. Deliverable 7.3. Technical report, EU TWENTIES Project
[6] T. Goodwin et al. (2014). Integrating enhanced dynamic line rating into the real-time state estimator analysis and operation of transmission grid increases reliability, system
awareness and line capacity, CIGRE 2014, paper B2-208.
[7] Nguyen, H.-M., Lambin, J.-J., Vassort, F., and Lilien, J.-l. (2014). “Operational experience with Dynamic Line Rating forecast-based solutions to increase usable network
transfer capacity”. CIGRE 2014, C2-103.
[8] ENTSO-E (2014), “Technical Report, Bidding Zones Review Process”, 2 January 2014. Page 51.
[9] Working Group B2-12 CIGRE. TB299: “Guide for Selection of Weather Parameters for Bare Overhead Conductor Ratings”, August 2006.
[10] IEEE (2006), IEEE Std 738-2006 - IEEE Standard for Calculating the Current-Temperature of Bare Overhead Conductors.
[11] Energy Sector Planning and Analysis (ESPA) for the United States Department of Energy (DOE), National Energy Technology Laboratory (NETL), Navigant Consulting
Inc., Warren Wang, Sarah Pinter – “Dynamic Line Rating Systems for Transmission Lines: Topical Report” (Smart Grid Demonstration Program), 2014.
[12] CIGRE TF 12-6 (B2), October 21, 2004 “Variability of Conductor Temperature in a Two Span Test Line” Tapani O. Seppa, Robert Mohr, Herve Deve, John P. Stovall
[13] ELIA implements DLR on 29 overhead lines http://www.elia.be/en/grid-data/DLR
Influence of the regulator and “cap vs risk” approach: http://www.elia.be/~/media/files/Elia/Grid-data/DLR/Explanatory-note.pdf
[14] David Gorarke, US Department of Energy, Indigo Advisory, “Managing the Energy Information Grid - Digital Strategies for Utilities”:
https://www.indigoadvisorygroup.com/blog/2017/11/8/digital-strategies-for-utilities
[15] The three steps of DLR (Ingles)
[16] Operating OHL in DLR mode (Ingles)
[17] The Ampacimon FAQ (en Español o Ingles)

45.
Jean-Louis Repetto & Rena Kuwahata (Ampacimon)
rena.kuwahata@ampacimon.com