Compact Self-Powered Wireless Sensors for Real-Time Monitoring of Power Lines

Abstract

This paper presents a highly efficient self-powered sensor with a radio-frequency (RF) transmission range of a few hundred meters. Magnetic energy from power lines was harvested and converted into 3.3 V pulsed voltage using a voltage doubler and an autonomous switching circuit. A ferrite core with a high relative permeability of 3200 was used for magnetic harvesting, and a split core was employed to allow live-line installation without causing a power outage. Low power sensors, such as a temperature sensor, a current sensor, and a three-axis accelerometer, were included in the module to monitor the power lines in real time. Even under a very low magnetic field of 40 mu T, average harvested power of 1.8 mW was achieved and wireless multi-sensing was successfully demonstrated over 500 m.