Optimum coil design for inductive energy harvesting in substations

Roscoe, Nina and Judd, Martin; (2011) Optimum coil design for inductive energy harvesting in substations. In: Fourth UHVnet colloquium proceedings. IEEE, GBR, p. 12.

[thumbnail of Optimum_Coil_Design_for_Inductive_Energy_Harvesting_in_Substations.ppt] Microsoft PowerPoint. Filename: Optimum_Coil_Design_for_Inductive_Energy_Harvesting_in_Substations.ppt

Download (1MB)


The reliability and life expectancy of electrical supply equipment can be improved through the use of condition monitoring. However, expansion of existing condition monitoring through the addition of new sensors is challenging since power to condition monitoring sensors has traditionally been supplied by mains power, which is not available in many locations where monitoring would be useful, or by batteries, which require their own maintenance regime. Energy harvesting in substations has the potential to power a new class of “fit-and-forget” wireless sensors, thus enabling more affordable expansion of condition monitoring. There are many potential sources of energy in substations (solar, wind, thermal, etc.), each of which may have a role in a particular range of sensor applications. This paper is concerned with inductive energy harvesting from the ambient magnetic fields, focussing on optimal coil design. By this means, the intention is to develop a class of “free-standing” inductive energy harvesting devices, which can be placed at a safe distance from high voltage conductors. In this paper, all aspects of coil design are considered, including core material, core geometry and number of turns. A coil is then designed for a representative application, taking practical limitations into account, and its output power is characterised while harvesting from a uniform 50 Hz magnetic field generated within a set of Maxwell coils. Experimental results are presented and discussed.