Transcript Document

On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
On-line monitoring of OHL
Conductor Temperature;
Live-Line Installation of the
RITHERM System
Stelian Alexandru Gal- Transelectrica, Romania,
Marius Nicolae Oltean- Smart, Romania
Traian Fagarasan- Smart, Romania
Mircea Opincaru- General Management, Romania
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Who we are…
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
1. GENERAL WIEW ON ROMANIA NATIONAL
TRANSMISSION GRID CN TRANSELECTRICA SA
Transelectrica is the Romanian Transmission and System Operator
(TSO)- member of ENTSO-E (European Network of Transmission
Systems Operators for Electricity).
Transelectrica is responsible for electricity transmission, system and
market operation, grid and market infrastructure development,
ensuring the security of the Romanian power system.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
CN Transelectrica SA, runs currently
- about 9028 km of OHL, out of which:
• 155 km UN= 750kV
• 4,740 km UN= 400kV
• 4,096 km UN= 220kV
• 38 km UN= 110kV
-78 power substations,
of which:
• 1 subs. of 750 kV
• 35 subs. of 400 kV
• 42 subs. of 220 kV
-212 main
transforming units
totaling 36.343 MVA
CITTES 2011
S.C. Smart S.A. is the
maintenance subsidiary. It
has the same structure as
the “mother” company.
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
1.3. Sibiu Transmission Branch (ST Sibiu)
The equipment park managed by ST
Sibiu consists of:
● 8 power substations, of which:
- 4 substations 400 kV
- 4 substations 220 kV
● 987.375 km of OHL, of which:
- 556.917 km 400 kV
- 430.458 km 220 kV
● 23 main transforming units
totaling 4.272
MVA.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
THE NEED OF OHL PARAMETERS MONITORING
The electrical energy market in continental Europe - deregulated
The networks load grows proportionally with the production of energy
by using more types of renewable.
Development of wind energy production
=> fluctuating and difficult to plan energy transport.
=> moving more power via existing lines.
increasing the capacity of the existing OHL without increasing the risk
of equipment or system failure due to higher loading.
The sag of overhead lines are dimensioned at a specific temperature,
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
The Benefits of OHL Monitoring
Real-time rating of OHL parameters,
Optimized use of infrastructure
Quick reaction time for contingencies and responsiveness to weather
Elimination of unnecessary and often risky operator interventions
Safe and reliable operation above statistic ratings
Minimal disruption to the network when correcting line dispatch
Meeting new transmission reliability regulations
Raise transmission capacity by 15-30% to avoid network congestion.
Rapidly deploy solutions when capacity deficiencies are discovered
Accurately monitor sag on older lines, where design conditions are
least certain
Match overhead line ratings to actual load capacity and weather
conditions
Provide advance warning of impending clearance violations
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
RITHERM –SAW (Surface Acoustic Wave)
Technology
SAW were quantitively described by Lord Rayleigh in 1885,
He showed theoretically that waves can be propagated over
the plane boundary between an elastic half-space and a
vacuum, or a sufficiently rarefied medium (eg. air), where
the amplitude of the waves decay rapidly with depth.
They are mechanical (acoustic) rather than
electromagnetic.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
 SAW transducers use piezoelectric
crystals with “reflectors” at predetermined intervals
 When the incoming radio energy is
transformed to a sound wave
propagating along the surface of the
tag, each location reflects part of the
signal back.
 The spacing of these reflections (or
echoes) indicates the location and
relative position of each reflector.
 The position of each reflector can
then be calculated and translated
into a data representation.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
OHL Temperature monitoring
 A high frequency electromagnetic wave at the 2.45 GHz ISM band is
transmitted to the sensor by use of the transmitting antenna
 The incoming high frequency signal is transmitted to an acoustic
surface wave
 At several positions parts of the signal are reflected on integrated
reflectors.
 The reflectors position is changed due to temperature elongation of
the crystal.
 The propagation velocity depends on the temperature.
 The reflected signals are converted to high transmission frequency by
the transducer and sent back to the receiving antenna of the system
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
The monitoring system consists of four elements:
- SAW (Surface Acoustic Wave) sensor with helical fixing rod
- Central Unit
- SAW extension box with radar antennas
- Evaluation program for the control center.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch

The conductor temperature takes the ambient temperature into
account and has a tolerance of 3K.

The server software is responsible for data transfer between the central unit
on the tower and the server and for calculating the prospective conductor
temperature.
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The client software shows the calculated conductor temperature on a
graphical interface using a three-color code.
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The program calculates the temperature of the core of the cable, which is
the hottest point and therefore responsible for the conductor-sag.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Live-line Monitoring System Instalation
General Conditions for the work.
It is necessary that the following
parameters of the OHL are known:
 tower geometry
 insulators type
 conductors type
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Minimum working team:
 One LW foreman - authorization type I 3T.
 Two (2) LW workers - authorization type I 1T.
 Four (4) LW workers -without LW authorization.
For the temperature sensor mounting on the active conductor of
the OHL, the work was executed by the bare hand method.
 For the solar panel mounting (the transducer and the
transmitter), the work took place after the LW method of
working at distance.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
It is necessary to bring the OHL in the Special
Exploitation Regime (SER):
 canceling the Automatic Reset (AR) on both OHL
ends.
 ensuring radio or telephone connections between the
working area and the dispatch,
 manually connecting the OHL, can be done only with
the agreement of the foreman.
CITTES 2011
Rated
Voltage
Un [kV]
Voltage
distance
dt [m]
Safety
distance
dp [m]
Minimum
distance
D [m]
220
1,10
0,50
1,60
400
2,00
0,50
2,50
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Weather Conditions
It is forbidden to start the work in the following weather
conditions:
 showers (rain, snow, drizzle, hail,) or relative humidity higher
than 80%,
 thick fog,
 strong wind (over 9.5 m/s),
 lightning (storm) in the working area.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Working Method
 The operators are equipped with full electro-conductive
equipment.
 the conductor access ladder is mounted on the conductor
 The mobile part of the ensemble is lowered to ground level.
 An operator climbs up the ladder.
 The operator is lifted from ground level to the conductor,
where he fixes the mobile carrier to the fixed one.
 He sets the sensor in place on the active conductor
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
 In order to install the solar
board, the converter and the
transmitter, two operators climb
the tower, close to the
temperature sensor mounting
area.
 The system elements are
mounted, one by one.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
PRESENT AND FUTURE OF OHL
MONITORING IN ROMANIA
Monitoring System version 2 (OTLM)
The OTLM system:
-Housing
-Supplying current transformer
-CPU
-Measurement unit (conductor temperature, conductor
current, GPS position)
-Communication unit with a GSM/GPS antenna
-On-line monitoring system centre programe package:
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Real-time examination of all measurements:
 Conductor temperature measurement
 Line current
 GPS position measurement
Review of all real-time high-resolution events (statuses):
 Alert thresholds, when the conductor temperature is exceeded [°C]
 Alert, when the temperature limit is exceeded T> in T»
 Diagram display
 Graphic overview of the line along with the operating device
examination
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Tension Based Monitoring System (CAT1- Nexans)
 Nexans system measures the tension in OHL’s conductors and
the net radiation temperature, taking into account the effects of
ambient temperature along with wind and solar effects,
emissivity and conductor time constant.
 Measuring the tension we may have a very high accuracy of
sag measurement (3-6 cm). Maintaining the tension in the
designed limits we are able to insure the designed sags.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
The main components of CAT1 system:
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Main unit
Solar panel supply and backup battery
Cellular or radio communications
Ambient temperature sensor
Load cells
Net Radiation Sensor
CAT-1 Master Base Station Software
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
EMO SYSTEM (Easy Monitoring Overhead
Transmission)- (MICCA)
CITTES 2011
COMPONENCE
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Sensors on OHL (temperature- reference and ambiental)
Hoarfrost sensor
Central Unit
Software platform
Corona protection
Anemometeru\, CO2 monitoring (solar pannel nedeed)
Barometer
Higrometer
CITTES 2011
EMO’s advantages
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Easy and fast installation
Operating with long live cycle batteries
Cost savings in the range of 15% to 35%
System accuracy of +/- 1,5 °C
The thickness of the ice can be determined
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
All systems are ready for the integration in Smart Grids.
CITTES 2011
On-line Monitoring System Of Ohl Parameters.Field Experince In Transelectrica -Sibiu Branch
Conclusions

Processing measurements monitored by integrating dedicated
software for monitoring and diagnostics on the OHLs enables quick
and correct information, making the best decisions in real time on the
management and safe operation in the energy system.

Monitoring systems are viable and relies on equipment and advanced
technology solutions, the latest generation, which correspond to
specific current international standards.

The development of the system will be useful on the reconductored
lines and on the wind-farms power exhausting lines.

Live Working technologies becomes mandatory for the erection
actions. It is a safe and efficient technology.
CITTES 2011
 THANK YOU FOR YOUR KINDLY
ATTENTION !