Expanding Commitment to Ensure Reliability and Performance of Electric Transmission and Distribution Systems

LIOS Technology has a rich experience in applying its distributed temperature sensing systems to various industrial applications. Power cable monitoring projects at transmission and distribution levels are an essential part of our business. With more than 10 years of experience and more than 2500 DTS systems in permanent operation world wide LIOS Technology is in a unique position.
EN.SURE is LIOS’ continuous and cost-effective monitoring solution of the electric power transmission and distribution grid and is the key factor for a successful Smart Grid implementation.
Following a global trend also our customers in the USA are expanding their commitment to ensuring the reliability and performance of the transmission and distribution systems they operate. LIOS EN.SURE supports that commitment and is the flexible solution for underground high voltage cables, overhead transmission lines and submarine cables as well as for array cables within on and offshore wind farm installations.
Please find below some examples of recent EN.SURE installations in North America.
 
Utility in the Northwest of the USA, 115kV U/G transmission line

• 1 circuit of 115kV 2,500kcmil (i.e. 1,250mm²) Cu insulated (XLPE) cable of approximately 4km long
• 1  DTS monitoring system (4km, 1 channel, multimode 50/125µm) to monitor <1km at="" cable="" li="" of="" this="" time="">
• Fibre optic sensor cable ( metal free FRNC, 4 multimode fibres ) installed in a separate duct
• Direct DTS data interface with Virtual Machine for temperature data reading
• DTS commissioning in June 2012

 

 

 

 

 

 

 

 

 

 

 




PowerSouth in Andalusia, AL, USA

• 115kV Wolf Bay Crossing U/G transmission line
• 1 circuit of 115kV 2,500mm² enamelled Cu insulated (XLPE) cable of approximately 2km long
• 1 DTS monitoring system (2km, 6 channel, multimode 50/125µm) to monitor HDD cable route
• Fibre optic sensor cable ( FIMT, stainless steel tube, 2 multimode fibres ) embedded in the power cable sheath  (copper wire shielding, corrugated stainless steel sheath)
• Direct DTS data interface with PowerSouth Virtual Machine for temperature data reading
• DTS commissioning in June 2013

 


 
 
 
 
 
 
Utility in the Northeast of the USA, 230kV U/G transmission line

• 2 circuits of 230kV 3,000kcmil (i.e. 1,500mm²) Cu pipe-type (HPFF) route length approximately 10km long.
• 1 DTS monitoring system (10km, 8 channel, multimode 50/125µm) to monitor ~10km of cable
• Fibre optic sensor cable (HDPE underground, 2 multimode fibres) installed in separate duct with temperature trees (at each end) for ambient temperature readings
• Direct DTS data interface with enhanced visualization and  Real Time Thermal Rating (RTTR) with Energy Management System (EMS) via DNP3 protocol
• DTS/RTTR commissioning in May 2013

 

 

 

 

 

 

 

 

 

Cigre Session 2012: Join 6000 Executives and Experts from the Worldwide Power Industry in Paris

LIOS Technology is pleased to cordially invite you to attend the CIGRE Technical Exhibition in Paris:

International Council on Large Electric Systems Technical Exhibition LIOS booth 232

27 - 31 AUGUST 2012, Palais des Congres de Paris, Paris, France 

 
LIOS Technology introduces its new EN.SURE DTS generation for Distributed Temperature Monitoring of Energy Transmission and Distribution Systems.
LIOS EN.SURE offers exact dynamic cable rating based on the real time temperature measurements along the entire cable circuit.
One single EN.SURE evaluation unit provides fast temperature sensing profiles with high spatial resolution along the optical fibre routes with monitoring ranges up to 40km per channel. It is the first maintenance free DTS which comes without any moving parts like fans or shutters.
 
» Register online for CIGRE Session 44 (technical exhibition included)
» Register online for CIGRE Technical Exhibition 

 

40 per Cent Increase in Power Transmission Capacity between Finland and Sweden

For two major North European utilities ( Fingrid Oyj and Svenska Kraftnät ) LIOS Technology provided its  most advanced multimode Distributed Temperature Sensing (DTS) systems to monitor the HVDC subsea link between the two utility grids. The electricity transmission connection is crossing the Gulf of Bothnia between southern Finland and Sweden.
The Fenno-Skan 2 HVDC project creates a new 800 MW, 500 kV subsea electricity transmission connection following a 200 km route.
It forms a bipolar arrangement with the existing 550 MW, 400 kV Fenno-Skan link, commissioned in 1989, providing a 40 % increase in power transmission capacity between the two countries.
The DTS systems provide real time distributed temperature sensing of the HVDC interconnecting subsea cable and land cables on both sides ensuring a save and stable grid operation.

International Workshop on Insulated Cables - in São Paulo, Brazil

 LIOS Technology GmbH- Linear Optical Sensors is pleased to invite you to attend the conference “ Redes Subterraneas De Energia Electrica 2011 ”, taking place in São Paulo, Brazil.
The Brazilian National Study Committee of Cigré B1 – Insulated Cables – is going to promote an International Workshop on Insulated Cables “ Workshop Internacional Sobre Cablos Eletricos ” , this year in São Paulo, Brazil.
The workshop taking place 20 – 22 June 2011, will be composed of short tutorials with international specialists on the following subjects:

• State of the art of technologies for maintenance of underground transmission lines (138 kV and above). The preferential methodologies that will be focused will be: measurement of partial discharges in field, detection and localization of small oil leakages in OF cables, and other maintenance edge technologies.
• Monitoring of underground transmission lines in real time: distributed temperature, current capacity, partial discharge, etc.
• Methods of calculation of magnetic fields of underground transmission lines and mitigation of magnetic fields generated by underground facilities.
• New technologies for high voltage cables and accessories: high-temperature superconductors, hybrid joints, Y joints, "plug in" joints and terminations.

LIOS Technology is participating with two tutorials captioned “New Technologies for Maintenance and Monitoring Systems of Insulated Cables” (Novas Tecnologias De Manutencao E Sistemas De Monitoramento De Cablos Isolados De AT) focusing on new trends for real time condition monitoring of insulated high voltage cables. Theoretical backgrounds as well as hands-on experience of recent projects serve as a base for interesting discussions with the Brazilian specialists on insulated cables.
  
Read more:

	Distributed Temperature Sensing
	Essential for Smart Grid: Distributed Temperature Sensing for Real Time Power Cable and Overhead Line Monitoring

Integrated Condition Monitoring for High Voltage Cables: Direct link to SCADA / substation automation

The intrinsic temperature measuring system DTS based on LIOS Technology’s design, with fibre optic sensors either installed within the power cable’s cross section (FIMT - Fibre in metal tube ) or attached to the exterior of the cable, makes it possible to record the temperature profile along an entire cable route continuously, and to pinpoint the exact location of hot spots within a metre.

Most commonly the measured temperature profile data is transmitted via standard interfaces from systems of the DTS as required, and be either displayed or further processed by PC, PLC or SCADA systems. As a result of the increasing demands placed on the ability to network and integrate measuring systems into management systems, LIOS offers network components that summarise DTS data from several DTS units and transport or convert it to the required network standards and protocols like Modbus, DNP3, IEC60870-5 or XML based data interfaces (e.g. POSC).

Equipped with the Embedded Communication Module (ECM) the Distributed Temperature Sensing (DTS) evaluation unit is accessible by Ethernet/ LAN, holds its own IP address and is compatible with DHCP.
The on-board storage facility of measurement data provides automatic buffering of network break downs. It can handle multiple protocols, so the DTS can be directly linked to PLC or SCADA systems and communicates in various industrial protocol standards providing measured data and customised alarm information.
Hereby, the evaluation unit communicates as a TCP /IP server with several clients.

Features of the embedded communication module of the LIOS DTS controller:

• Configuration and operation of the DTS via two independent channels:
  
  
  • RS232
  • Ethernet TCP/IP
  
  
• Onboard storage of measurement data
  
  
  • Buffers up to 72 hours of measurement data and initiates data transfer automatically after communication link was re-established
  • Individual file access to measurement data through CHARON_02 (onboard data storage 1 GB)
  
  
• Allows to operate individual Plug-In-Interfaces for customer specific protocol solutions
  
  
  • The DTS can communicate in parallel with its proprietary protocol and one or more customer specific protocols like DNP3, IEC60870-5-104, IEC61850, POSC WITSML, Modbus (Master/Slave) etc.
  • Individual assignments for protocols and client addresses (IP) possible
  
  
• Ethernet communication to and from clients with high bandwidth
• Module comes with built-in user configurable Firewall and enables reliable operation even in WAN’s
• Secure data transmission and individual authorisation according TLS- Standard (RFC 2246)

The most common industrial protocols used in electrical systems worldwide are introduced in the following section. However, also other protocol standards are available or can be implemented for the ECM. Please contact us in case of questions.

MODBUS
The MODBUS protocol was published by Modicon in 1979. It is a quite simple single master – multiple slave protocol widely used in general purpose SCADA applications. It provides binary (bit) and 16-bit integer data, but no floating point values, polled by the master, i.e. the slave cannot send data spontaneously. The protocol specification is openly published and royalty-free. In the DTS ECM, TCP/IP is used as transport layer.

IEC 60870-5
IEC 60870-5 provides a communication profile for sending basic Telecontrol messages between systems. It was developed by the IEC Technical Committee 57 (Working Group 03) as a protocol standard for Telecontrol, Teleprotection, and associated telecommunications for electric power systems. The result of this work is IEC 60870-5. The protocol provides inter alia bit, integer and floating point data with or without time stamps. Data is transmitted from controlled stations (slaves) either by polling or spontaneously. In the ECM the IEC 60870-5-104 companion standard, defining standard TCP/IP connections as transport layer, is used.

DNP3
DNP3 (Distributed Networking Protocol) is an open standard managed by the DNP User Group. Initially; the DNP3 protocol was developed by Westronic (now GE-Harris) in 1993. It is widely used in electrical systems worldwide, including North and South America, the UK, Southeast Asia, South Africa, Australia, and New Zealand. It has gained wider use beyond electrical utilities, e.g. for water supply as well. The DNP3 protocol is also referenced in IEEE Std. 1379-2000, which recommends a set of best practices for implementing modern SCADA Master-RTU/IED communication links.
The protocol provides bit, integer and floating point data and time stamps. Data is transmitted from the outstation (slave) either by polling or spontaneously. The ECM uses TCP/IP as transport layer, but even in this mode the DNP3 protocol additionally uses its own protocol stack for synchronisation and error checking. This provides extra security.

US Renewable Energy Project Equipped with Real Time Condition Monitoring

For one of the biggest American renewable energy companies LIOS provided its well recognized DTS system for monitoring the temperature of two medium voltage power cables directly buried coming from a wind turbine towards the substation. All asset condition monitoring data from the controller is linked in real time by means of Modbus communication protocol to the operator’s SCADA system. The company is convinced by using DTS it has a better control over the thermal cable conditions thus over the load of the power cables which let it utilize its assets more economically. This is a great step for LIOS Technology to strengthen its position in USA for temperature monitoring of power cables at wind farms together with the recently opened office in Morganville, New Jersey.
 Read more:

	Smart Grid: Real time ampacity predictions of power cable and aerial line installations
	Distributed temperature monitoring of power cables

Condition Monitoring of high voltage cables: Turning information into extra capacity

Increasing demand for power is forcing power utilities to load power cables to their physical limit, and safety and efficiency concerns are making it more and more critical for operators to understand what is happening thermally both inside the cables themselves, and along the cable route.
Real Time Determination of Thermal Conditions along HV Power Cable Systems
During high-load conditions and under emergency circumstances (such as when a failure occurs in a segment of the grid and power must be shifted to other sections to compensate) it often becomes necessary to load cables right up to the limits permitted by the relevant regulations. In these operational situations, it must be ensured that maximum temperature limits are not exceeded. Due to the increasing complexity of the thermal relationships along cable routes, the ability to continuously measure the temperatures along the cable has proven invaluable, providing critical operational data to engineers, especially in the case of a system faults such as a hot spots that could result in cable failure if they are not corrected.
The intrinsic temperature measuring system DTS based on LIOS Technology’s design, with fibre optic sensors either installed within the power cable’s cross section (FIMT – Fibre in metal tube ) or attached to the exterior of the cable, makes it possible to record the temperature profile along an entire cable route continuously, and to pinpoint the exact location of hot spots within a metre. Since the measuring principle employed is purely optical, the presence of electromagnetic influences, which can result in false sensor signals in other technologies, does not affect the DTS unit.
Distributed temperature sensing is a powerful tool that allows the accurate rating of high voltage power cables in real time, and provides the following operating benefits:

• Reduce power outages or blackouts
• Ensure continuity of supply
• Activate hidden capacity reserves of existing assets
• React quickly to overload conditions
• Conduct precisely and in real-time load predictions as new sources of energy are added to the grid

The temperature profile data, in any desired form or format, can be transmitted via standard interfaces from systems of the OTS product series as required, and be either displayed or further processed by PC, PLC or SCADA systems. As a result of the increasing demands placed on the ability to network and integrate measuring systems into management systems, LIOS offers network components that summarise DTS data from several DTS units and transport or convert it to the required network standards and protocols like Modbus, DNP3, IEC60870-5 or XML based data interfaces.
Dynamic Cable Rating
LIOS also provides an integrated Real Time Thermal Rating (RTTR) package via a well defined interface between its DTS data visualisation software and a commercialised – the industry’s de facto standard – cable ampacity program based on IEC standardised methods (mainly IEC 60287 and IEC 60853). Dynamic rating software couples the accurate temperature data provided by the DTS unit to predictive functions of cable ratings, providing engineers with even more information upon which they can base distribution and load decisions. The result is dramatically more efficient transmission of power, fewer “brown-outs”, and decreased operating costs.

The ideal sensor embedded in power cables: Fibre In Metal Tube (FIMT)

The optical fibre serves as the distributed temperature sensor for LIOS DTS systems and is typically surrounded by a protective layer. It is preferably encased in a stainless steel tube which significantly increases the mechanical stability of the sensor. Fibre encapsulated in stainless steel tube or short “Fibre In Metal Tube (FIMT)” is a hermetically sealed rugged construction for very long lengths of optical fibres. Furthermore, it is particularly effective in protecting against the hydrostatic pressures, high temperature effects and corrosive environments.
The inside of the FIMT metallic tube may lined with gel to ensure that the sensor cable remains permanently water-proof. This viscous gel protects the fibres from many environmental concerns, prevents damage from microbending conditions and helps to minimize the forces applied during spooling and deployment.
An important parameter to consider with FIMT is the Excess Fibre Length. It is defined by the percentage of excess fibre loaded into the metal tube during processing to relieve induced stresses directly related to the differing thermal coefficient of expansions of each material contained in the construction. FIMT is exposed to drastic and often rapid changes in temperature and pressure, so the Excess Fibre Length must be considered to ensure continuous, robust performance across all operational conditions.
FIMT constructions contain individual or multiple fibres (single mode or multi mode) and are available in sizes ranging from 1 mm to 3 mm outer diameter, variations in effective wall thickness are possible as well. FIMT serves as the core for various fibre optic sensor cable constructions or may be integrated into high voltage cable designs directly.
The FIMT is manufactured from a special stainless steel strip. During the manufacturing process this strip is formed to a tube and welded along its length. The stainless steel tubes must be hermetically sealed for all applications. For this reason the complete weld seam is subjected to a leak proof test by means of eddy current. By means of a drawing process the desired final diameter is attained on the one hand and an increase in strength through cold conversion on the other. During the manufacturing process the optical fibres are inserted into the tube. They are clearly differentiated by means of a specific colour code. At the end of the production process the tubes are subjected to a complete optical attenuation measurement and then documented for back-tracing. Additionally, each length produced is subjected to a weld penetration test, each weld seam undergoes a leak test, and the Excess Fibre Length is checked.
LIOS offers a variety of FIMT constructions perfectly suitable for distributed temperature sensing applications along power cable transmission systems.