Ensuring a reliable supply of electrical power for today’s world
As demand for electricity continues to grow, so do the challenges to power companies and power grids. The liberalisation of power supply markets continues apace, resulting in the reorganisation of national and international networks. Events of the past few years – including large-scale blackouts and shortfalls in major markets, and the ongoing addition of alternative sources to existing networks – point up the need for improvements to existing infrastructures. At the same time, there is increased pressure to keep costs to a minimum.

Meeting the demands of a changing power environment
Providing sufficient electrical power reliably requires ongoing monitoring of temperatures within overhead transmission lines. The LIOS condition monitoring system is an inexpensive and highly reliable method that enables real-time monitoring of an entire network or of selected critical spans.

The easy-to-install, low-maintenance system offers a multitude of advantages. By enabling dynamic analysis of network structure, it increases the overall safety and reliability of the grid. It facilitates dynamic reactions to transmission requests, resulting in more flexible capacity and revenue management in both the short and long term. And the potential for cost-savings is enormous: Downtimes and blackouts can be avoided, and the need for new lines and upgrades (e.g. increasing the height of overhead transmission lines) can be greatly reduced.

Customers employing the LIOS condition monitoring system can also increase earnings by activating previously unused resources in existing power lines. Dynamic metering of grid capacity and maximized transmission capacity make it possible to respond quickly and dynamically to transmission requests. As new sources of energy are added to the grid, precise load predictions are possible and it is easier to react quickly to overload conditions.

With the help of dynamic network-structure analysis, temperature profile can be monitored over span fields and fittings, depending on the length of the sensor. Load parameters are bundled and transmitted to network control stations online, allowing for real time thermal rating (RTTR) - which means real time supervision of network capacity. This makes it possible to predict load precisely and to avoid the wire fatigue caused by repeated thermal loads. Because decisions based on thermal load often influence upgrading or installation of lines, this translates into better control of grid and wire conditions, as well as optimal sag control and line clearance without requiring new construction activities.

All in all, the LIOS condition monitoring system offered by LIOS Technology provides an excellent all-round solution to many of the challenges facing power supply companies today. Remote repair, maintenance and calibration of the systems is standard. Maintenance can be performed without requiring interruption of electrical transmission, and even without requiring access to the line. The variable sensor lengths embedded inside the cable provide measurements accurate up to 1°K, independent of environmental conditions and weather.

If you are looking for high reliability and low system costs in a temperature measuring system, look to the partnership of LIOS Technology.  We will be happy to show you how you can increase grid security and prolong the working life of your facilities via a complete network-monitoring solution.


State-of-the-art temperature measurement system
The temperature sensor element as such is a passive optical fibre that is integrated into the core of a phase wire of overhead transmission lines (OPPC). In addition to transmitting electricity, optical fibres make it possible to implement a wide range of sensor applications.

Via joints and high-voltage fibre-optic uncoupling devices, the fibre is linked to an DTS evaluation unit (OTS controller), where the distributed temperature profile is recorded and can be further processed. The temperature profiles themselves, or the results/events derived from them, can be transmitted via standard interfaces from the evaluation unit as required, and be either displayed or further processed in real time by PC or PLC systems.

Depending on the topographic location, it is possible to use cable, fibre optic or wireless GSM connections to feed into the utilities’ overall management system, where the profile data serves as a valuable basis for reliable load prediction.

Systems of the OTS product series are linear temperature measurement devices belonging to the latest generation of fibre-optic sensors. Their technical measuring characteristics make them particularly well-suited to locally-distributed temperature surveillance of cable and transmission line systems. The OTS systems measure temperatures by means of optical fibres functioning as linear sensors of all kinds. Temperatures are recorded along the sensor cable, i.e. not at points, but as a continuous profile. Temperatures can be measured accurately even with short monitoring times and over great distances.

Overhead phase wires and metering systems
The fibre-optic sensor element is a purely passive optical cable. Flexible and easy to install, they are immune to electromagnetic interference and absolutely maintenance-free. The OTS evaluation unit provides the precise measurement of temperature profiles along several kilometres of sensor cable. Commissioning and maintenance, as well as the division of the sensor route into zones and sub-zones using software as required, can be accomplished easily without cutting off power to the affected line section.

Maintenance and remedial actions can be conveniently managed via remote access. The design of this monitoring system is straightforward and its configuration for a particular project requires only a few steps using efficient software, so network operating staff can carry out commissioning and maintenance procedures after a reasonably short training session.

These are the main benefits for customers using the LIOS condition monitoring system  for electrical overhead transmission lines:

• Reduced costs
• Flexible revenue management
• Dynamic analysis of network structure
• Improved grid safety

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