Introduction: This project is to validate a concept for an easily retro-fitted sensor for measuring and/or deducing the temperature of the core of a 3-phase electricity network power cable. Using cable temperature to infer the current in a cable offers the possibility to use this approach to provide a lower cost, more easily installed alternative to current transformers. It also provides a retro-fit alternative to fibre-optic cable temperature sensing. Additionally the measurement of the core temperature can be used to gauge when a cable reaches its temperature tolerance levels independent to the power being transferred.

Objectives: The problem being addressed by this project is to measure the cable core temperature at regular intervals using a sensor attached to the outer sheath of a cable. The sensor ideally is to be small, easily retro-fitted and will be of relatively low cost to manufacture. Two potential methods of temperature measurement were to be under consideration as follows:

Direct temperature measurement of the cable sheath with a computational model inferring a virtual temperature sensor at the cable core. The computation would be based on a cross-sectional thermal model of the cable components and materials.

Direct heat flux measurement to quantify the amount of heat exiting the cable, using the thermoelectric effect - also known as the Peltier and Seebeck effects depending on the direction of conversion between heat and electricity.