Non-invasive energy harvesting for wireless sensors from electromagnetic fields around 10kV three-core power cables

With the rapid development of Smart Grid, urban distribution networks have greatly expanded, in which power cables have been widely used in many countries. Monitoring of power cables will increase reliability of supply and the integrity of the transmission system. Wireless Sensors Nodes (WSNs) are independent sensors which can sense and monitor certain parameters including temperature, humidity, load condition, etc., and then transmit the data collected wirelessly to a base station. Power to the WSNs is usually provided by batteries. However, batteries have a finite amount of energy and need replacement when exhausted, which is a great cost of manpower. This paper presents an improved approach based on electromagnetic induction to take energy from electromagnetic fields around 10kV three-core cables. The whole energy harvesting system is composed of three parts: energy-gaining coils, rectifier & filter circuit, energy storage & regulated output circuit. The performance of this methodology is evaluated under simulation using Ansoft & Simplorer and laboratory tests. The results indicate that this proposed non-invasive energy harvester can collect energy from surrounding electromagnetic fields of three-core cables, and generate impulse power of tens to hundreds of milliwatts which can meet the requirements of WSNs. Key points of future work are highlighted at the end of paper.