Comparative Analysis and Optimization of Magnetic Field Energy Harvesters Based on Split Three-Phase Power Line Joint Energy Harvesting

With the rapid development of smart grids, abundant online monitoring sensors are installed at critical nodes of medium and low voltage power lines. To ensure reliable operation of these monitoring sensors, the power source problem needs to be solved urgently. The magnetic field energy can be captured and used as a stable energy source for online monitoring sensors. However, the single-phase magnetic field energy harvester (MFEH) tends to achieve low energy at low currents, and the output power is significantly influenced by load fluctuations. Motivated by these challenges, a three-phase distributed magnetic field energy harvester (TDMFEH) with transforms is proposed in this article. The power multiplier changes of the TDMFEH compared with the single-phase MFEH are further analyzed. Moreover, this article proposes an output power boosting control method under load fluctuations with single-phase and three phase joint energy harvesting, to achieve higher output power with a wide range of load connected. The experimental results demonstrate that the TDMFEH can achieve a maximum power ratio of 2.13 compared to an equal-volume single-phase MFEH. Besides, the output power can be enhanced with the switching between single-phase MFEH and TDMFEH when the load fluctuates.