Improving Magnetic Energy Harvesting via Desaturation with Reverse Voltage

Magnetic energy harvesting (MEH) extracts energy from magnetic fields generated by AC current-carrying wires. This type of energy harvesting offers a relatively high power density compared to other ambient energy harvesting methods, suitable for self-powering low-power devices such as embedded systems, sensor nodes, and Internet-of-Things (IoT). Previous research has shown that the magnetic core should operate in an appropriately saturated state to obtain the maximum power output. Magnetic saturation is necessary because the energy magnetically stored in a physical volume of the core increases as the core approaches saturation. However, the actual energy harvesting electrically stops once the core reaches full saturation. However, the actual energy harvesting electrically ceases once the core reaches full saturation. We propose a new desaturation scheme that employs an additional control voltage to reverse the core voltage once the magnetic core is driven into saturation, thereby generating multiple energy harvesting windows in each cycle and enhancing the harvested power via MEH. Circuit simulations and experiments are conducted to examine the effectiveness of the proposed desaturation approach. The results demonstrate that the proposed desaturation scheme can double the harvested power of MEH systems compared to the scenario without the implementation of the proposed desaturation scheme.