Comments on “An Effective Power Improving Method of Magnetic Field Energy Harvesters Using a Series-Connected Capacitor for Wireless Sensors in Smart Grids”

In the article “An Effective Power Improving Method of Magnetic Field Energy Harvesters Using a Series-Connected Capacitor for Wireless Sensors in Smart Grids” by Li et al. (2024), the enhancement of magnetic energy harvester (MEH) performance by adding a series-connected capacitor was discussed. It was shown that the optimal (in terms of harvested MEH power) capacitance value is inversely proportional to the load resistance value. Yet, some functional properties could have been missed out due to the adoption of a high-permeability ungapped core (without calling into doubt the validity of presented results). Moreover, optimal transfer window length was not obtained. Consequently, the purpose of this comment is twofold: demonstrating some operational details not highlighted in Li et al. (2024) and complementing them by providing analytical expressions for optimal transfer window length and corresponding harvesting potential of the MEH. Experimental results validate the complementary comments.