A Nonintrusive Power Supply Design for Self-Powered Sensor Networks in the Smart Grid by Scavenging Energy From AC Power Line

An advanced metering and monitoring system based on autonomous, ubiquitous and maintenance-free wireless sensor networks is of great significance to the smart grid. However, the power supply for sensor nodes (especially those installed on high-voltage side) remains one of the most challenging issues. To date, miniaturized, reliable, low-cost and flexible designs catering the massive application of self-powered sensor nodes in the smart grid are still limited. This paper presents a nonintrusive design of power supply to support the sensor network applied in the smart grid. Using a cantilever-structured magnetoelectric (ME) composite, the energy harvester is able to scavenge energy from the power-frequency (50 Hz) magnetic field distributed around the transmission line. Design considerations for this specific type of scavenger have been discussed, and optimized energy harvester prototypes have been fabricated, which are further tested on a power line platform. Experimental results show that the single-cell and double-cell energy harvesters are capable of producing 0.62 mW and 1.12 mW at 10 A, respectively, while corresponding power outputs are enhanced to 4.11 mW and 9.40 mW at 40 A. The good energy harvesting ability of this particular ME composite indicates its great potential to make a nonintrusive, miniaturized, flexible and cost-effective power supply, which possesses great application prospects in the smart grid.