Optical Fibre for Temperature Measurement in Power Systems

Optical fibres are known to be used in power systems because they withstand the rough conditions in high voltage environments – as such they are used in Substations for carrying messages, e.g., according to IEC 61850.

There is another very interesting use case of optical fibres in power systems: in generation, transport, distribution, and loads. One of the crucial measurements that can be applied to more efficiently use of electric power is measuring temperatures. But you may state that installing a lot of temperature sensors could be quite expensive!

With the application of optical fibre for measuring temperatures it seems to be a very promising approach to reduce the amount of power needed for many critical process like in huge data centers, high voltage lines and cables, transformers, switch gears, to name a few.

According to alquist (a UK based company specializing on measurement systems using fibres) there are many advantages of fibre as a temperature sensor:

• Simultaneously measures temperature and position over long distances
• Low cost – the sensor is made from standard 50/125 optical fibre zip cord - very cost effective
• Immune to shock/vibration and electromagnetic interference
• No electronics, wireless, batteries or moving parts in monitoring zone. Totally passive, minimal maintenance.
• Inherent high reliability (fibre has a design life of 30+ years)
• High temperature range -200°c to +500°c
• Extremely small for access in legacy areas with restricted space
• Easily installed in without any downtime or interruption of service

There are an incredible number of applications for fibre optics beyond their use as a simple communications links.

Download a very useful presentation given by Andrew Jones (alquist) [pdf, 2.8 MB]

The availability of myriads of “measurement signals” from various processes allows to more efficiently use energy, i.e., to reduce the amount of energy we need to consume to service our needs for modern life.

What ever will be measured in energy supply systems could be modeled and communicated with IEC 61850 – The Communication Standard for power system automation. One crucial focus of IEC 61850 is on measurements!