A Power Enhancement Method for Electric Field Energy Harvesting System Based on Resonant Compensation and Mutual Inductor Optimization

The electric field energy harvesting (EFEH) system based on the line voltage features unique power supply stability for secure and reliable power supply to state monitoring sensors. However, its application is limited by the low power output. Increasing the equivalent impedance to enhance power output is an effective approach. Nonetheless, existing methods have limitations in analyzing and optimization impedance conversion and neglect the influence of the equivalent series resistance on the power enhancement. To address this, this work investigates the power enhancement method for EFEH system based on resonant compensation and optimized mutual inductor. Firstly, the influence of resonant compensation and winding parameters on system output power is well analyzed. Then, an optimization method for enhancing power by optimizing mutual inductor parameters is proposed, where the optimal values of coil turn distribution are designed to achieve high power output. Finally, a prototype is developed based on the proposed method for testing. Experimental results demonstrate that with a given magnetic core size and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$100\mu\mathrm{A}$</tex> displacement current, the optimized output power can reach 26mW, confirming the effectiveness of the proposed method.