The Electricity Transmission

and Distribution (T&D) network

of the 21st century, commonly

called “the Grid”, has to be

substantially reengineered to

cope with the recent evolu-

tions in the energy sector. On

top of a sustained growth in

demand, deregulations, privati-

zations, globalization, com-

bined with the introduction of

new and cleaner sources of

generation are significantly

impacting the Grid in many

aspects. Power flows become

complex, difficult to predict, to

impact and to monitor.

This substantial complexity

led to dramatic events in the

past few years. The Italian

blackout (Sept 28th, 2003) as

well as New York blackout

(August 14th, 2003) have their

origin in air breakdown be-

tween trees and power line

due to a vertical clearance

violation.

More recently on November

4th, 2006 a major blackout in

the whole Europe was just

avoided. Still it affected 15

million people after a se-

quence of cascading events,

initially due to the activation of

a conservative thermal limit for

a 400 kV line in Germany,

although the occurrence hap-

pened during the night, in win-

ter time and with high winds.

Luckily new technologies ena-

bling the evolution from the

t r a d i t i o n a l G r i d t o

“SmartGrids” are already avail-

able today. These robust and

safe technologies allow real-

time monitoring, will optimize

the T&D assets utilization, will

increase the trans-boundary

business opportunities, and

are relatively easy to deploy

within the existing infrastruc-

ture.

A reliable Real-Time Ampacity

monitoring tool is a critical

component of any “SmartGrid

toolbox”.

Ampacity is defined as the

maximal current rating an

overhead line can support

before excessive sagging oc-

curs, that could violate safety

distances to the ground, trees

or buildings. Sagging is due to

thermal expansion of the line,

a complex function of the air

temperature, solar radiation,

humidity, the presence of

snow or ice, the local wind

and of course the actual cur-

rent [1][1][1][1]. Due to the intrinsic

difficulty in measuring accu-

rately the line temperature, a

static line rating is traditionally

defined based on worst case

w e a t h e r a s s u m p t i o n

(maximum solar heating, maxi-

mum external temperature,

minimum wind speed, ...).

Real time Ampacity is most of

the time higher than this static

rating.

An accurate real-time Ampacity

monitoring equipment allows

to exploit the full capabilities

of existing lines. Experience

shows that 10-30% additional

capacity can be safely created

with real-time versus static

ratings. The system enables

also a safer decision process

during contingency situations,

that could otherwise ultimately

lead to dramatic blackout

events as illustrated earlier.

Finally the substantial engi-

neering knowledge and statis-

tics collected from real-time

observation helps to build

tools for Ampacity prediction,

to detect anomalies on the line

(ice, excessive winds, chain

defects…) and will guide opti-

mal capital investments deci-

sions [2], [3].[2], [3].[2], [3].[2], [3].

Real Time Ampacity, key component of SmartGrid toolboxes

University of Liège, Department of Electricity, Electronics and Computer Sciences, Belgium.

December 2008 Version 0.1, preliminary

Real-Time Ampacity Monitoring with

Ampacimon™

Black out in New-York, August 14th, 2003.

Summary :

• Ampacimon™ is an acronym for

“Ampacity monitoring”.

• CIGRE [4][4][4][4] defines the current

carrying capacity from a thermal

viewpoint or ampacity as follow :

“The ampacity of a conductor is

that current which will meet the

design, security and safety crite-

ria of a particular line on which

the conductor is used”.

• Ampacimon™ is the only real

time rating device measuring

directly the sag by vibration

analysis, without the need of

any line or environmental data.

• Ampacimon™ is autonomous,

can be located anywhere on any

span, it doesn’t require calibra-

tion prior to first use, and can

be installed and operational live

-line in less than 20 minutes.

Ampacimon™ system 2

Ampacimon™ technical charac-teristics and certification

3

Ampacimon™ value proposition, contact

4

In this report :

December 2008 Version 0.1, preliminary

Ampacimon™ [1] [1] [1] [1] is an online

monitoring system, enabling

direct measurement of the sag

based on frequencies analysis.

Thanks to this direct measure-

ment of the sag, the system

provides the most accurate

real-time line ratings (Precision

on sag is up to 2%).

System is made of Ampaci-

mon™ modules, or Ampaci-

Boxes (Figure A), directly

clipped on the overhead lines.

The modules communicate via

a standard cellular radio (GSM-

GPRS) to a Ampacimon™

server, Ampaci-Server, directly

linked with the operator dis-

patching. Ampacimon mod-

ules can be upgraded in the

field from the server (software

upload and download).

Ampacimon™ does not need

any line nor any environ-

mental data to determine the

sag unlike other determination

methods, which may be very

disturbed by unknown environ-

mental effects and/or approxi-

mate structural data and/or

errors in topological data. Fur-

thermore, Ampacimon™ mod-

ules perform a complete vibra-

Ambient temperature and sag (as deduced by Ampacimon™ ) vs. time (at no load).

Page 2

Ampacimon™ system

Ampacimon™ on 380kV line (Courtesy Elia, Belgian TSO)

Ampacimon™ installation, July 2008 – 380kV line, Doel-Zandvliet (Courtesy Elia, Belgian TSO)

“Real time

monitoring is a

quickly applicable

solution at a

reasonable cost”

tion analysis (0 to 100 Hz),

allowing to evaluate perma-

nently ageing (evolution of the

“fatigue”). It helps to take pre-

ventive measures, like for ex-

ample the optimal introduction

of dampers the evaluation

their effects.

Ampacimon™ can be installed

on live line, either from heli-

copters or from the ground.

Installation time is very short

(typically 20 minutes per mod-

ule). The system is autono-

mous, as it gets his own power

directly from the line, and can

be located anywhere on the

span. Once installed the mod-

ule is directly operational and

will start communicating with

the remote server.

Fig A. Ampacimon™ end to end system

December 2008 Version 0.1, preliminary

Typical installation on live line in France at 90 kV on HT ACSS conductor.

(Courtesy RTE).

CAO view and actual view of Ampacimon.

corrosion, …). The power total power consumption is

below 10 Watts.

− The microelectronics system is equipped with a DSP proc-essor, Four 2D accelerome-Four 2D accelerome-Four 2D accelerome-Four 2D accelerome-tersterstersters and other sensors (temperature, humidity). It embeds software to perform

sag measurement.

− There are two radio systemradio systemradio systemradio systems: (i) 433 MHz (ISM license-free band) with limited power emission able to transmit at about 100 m. (ii) standard cellular module (GSM/GPRS) performing at 900, 1800

and 1900MHz

− All devices are carefully se-

Ampacimon™ module:

− Aluminium case of about 7kg (roughly 20 cm long, with section about 15x15 cm), including microelectronics devices. Anti-corona de-

signed.

Internal part of Ampacimon® is containing in appropriate loca-

tions :

− A current transformercurrent transformercurrent transformercurrent transformer spe-cially designed for Ampaci-mon® application (70 kV to 765 kV applications). A spe-cial design is used to protect the wiring from short circuit currents, lightning over-voltages and external envi-ronment harm (dampness,

lected to perform in harsh perform in harsh perform in harsh perform in harsh environmentenvironmentenvironmentenvironment with tempera-ture ranging from -40°C to

85°C.

Ampacimon™ server:

The Ampacimon server man-ages the communication links with the Ampacimon modules and reports the necessary information to the dispatching. The main software compo-

nents are:

− Modules communication

software

− Sag analysis software

− Ampacity prediction software

Ampacimon™ technical characteristics

Page 3

“All material are

carefully chosen to

be able to work in a

harsh environment.”

Typical ice overload problem.

− Vibration tests, 0-10Hz, 2g

− traction tests, more than

6kN

Ampacimon™ will comply with all relevant EMC requirements

(EN55011 and EN61000).

Ampacimon™ modules have already been validated in harsh conditions during field trials in UK, France, Belgium and Canada between 2004

and 2008.

The following certification tests have been performed success-

fully:

− Short circuit tests, 73 kA

for 120ms

− High voltage, Corona effect tests, >400kV phase to

ground

− Lightning tests, }1.2/50us,

340kV

Ampacimon™ Certification

Milano Labs Testing (Italy) May 2007.

(Courtesy Politecnico di Milano).

Traction tests, 2008(Belgium)

Ampacimon™ is a registered trademark

The team is including three units of research of

the University of Liège, Belgium :

Microsystems : Pr J. Destiné, Ir. T. Libert, Ir. O. Nguyen, Ir.

J.F. Paim, T. Legros

Spatial research center : Ir. J.-M. Gillis

Transmission and Distribution of Electrical Energy : Pr J.L.

Lilien, Ir. S. Guérard, Ir. B. Godard, Ir. H.-M. Nguyen

Ampacimon device, system and method are patented.

Patent number : WO 2007/031435 (A1)

Ampacimon™ system will be fully released for production

in June 2009. Preliminary technical information is avail-

able upon request info@ampacimon.com

[1] Cigre, 2006, “Guide for the selection of weather parameters for bare overhead conductor ratings”, TB299, WGB2.12.

[2] Cigre, 2007, “Sag-tension calculation methods for overhead lines”, TB324,Task Force B2.12.3.

[3] R. Stephen, 2001, “Surveillance des lignes en temps réel”, Electra n°197.

[4] Cigre, 2004, “Conductors for the uprating of overhead lines”, TB244, WGB2.12.

ReferencesReferencesReferencesReferences

Jean-Louis Lilien, Professor, PhD.

Transmission and Distribution of Electrical Energy

Montefiore Institute of Electricity

University of Liège

10 Grande Traverse, Sart-Tilman (B28)

B-4000 Liège, Belgium

Telephone : +32 4 3662633

Fax : +32 4 3662998

Email : lilien@montefiore.ulg.ac.be

Ampacimon™ value proposition “Unl ike many o th e r

methods, Ampacimon™ is

autonomous, can be located

anywhere on the span, it

requires no calibration prior

to first use, and it can be

installed live-line in roughly

20 minutes !”

Ampacimon™ system brings the following advantages to Transmission Service

Operators:

− Minimize operating costs by leveraging the existing capacity of the monitored line to prevent unnecessary re-dispatch, load shedding or

curtailment.

− Assist for a safe and reliable decision-making process during planned or unplanned contingency events, reducing the risks of incidents or even

blackout.

− Generate real time analysis and Alarms for exceptional events (chain defect, snow, ice…) allowing rapid and

targeted interventions.

Ampacimon™ is a real-time Ampacity monitoring system. The key differentiators of this technology versus its

competitors are:

− System measures directly the relevant parameter, i.e. the sag, and calculates the corresponding Ampacity, without relying on models or external data. System is

intrinsically very accurate.

− Installation is simple, can be

done on live-line.

− Straightforward integration up to the dispatching, relying on robust and standard cellular network and secure

Internet links.

− Planning for optimal exploitation of the existing assets, maximizing the network capacity, help short term forecast and leverage assets (intra-day buy-sell).

Reduce congestion

− Data collection, engineering analysis, support for assisting investment decisions, define network configurations, assessments

on line aging (see figure)…

http://www.tdee.ulg.ac.be

http://www.ampacimon.com

Power line cable strands failures due to Aeolian vibrations

(observation after clamp removal)

December 2008 Version 0.1, preliminary

Page 4