A novel high-performance three-phase magnetic field energy harvester for powering up vehicle onboard electronics

Abstract

The boosting development of vehicle electrification and onboard sensing networks in the intelligent vehicle era poses a significant challenge to conventional electrical power supply systems. This study developed a novel passive three-phase magnetic field energy harvester (TMEH) for reliable and sustaining power to drive vehicle onboard electronics, which recycles the induced magnetic field energy around the power lines of a permanent magnet synchronous motor (PMSM) on an electric vehicle (EV). A Y-Y topological connection pattern for three-phase coils was designed to enhance and stabilize the TMEH output performance. Furthermore, three auto-shift operating modes were assigned to the TMEH to tackle the dynamic changes of the captured power caused by unpredictable vehicle manoeuvres and road conditions. The theoretical model and numerical method were also established for structural optimization of the TMEH, followed by a series of experimental tests for highlighting the impacts of the power lines carrying alternating current on TMEH. The results have indicated that the proposed TMEH showed impressive energy conversion efficiency, providing an independent power supply for sensors and other electronics applications on a 4 kW-PMSM driven EV. Bench testing results and practical EV driving trials demonstrated the capability of the TMEH prototype to power up multiple types of sensors and electronic devices under most EV driving conditions. Specifically, an average power of 5.69 W and power density of 123.85 mW/cm3 were generated by the harvesting coils when excited by a 50 A current at 50 Hz. Furthermore, the maximum TMEH energy conversion efficiency of 41.9% at the excitation current frequency of 50 Hz is obtained in laboratory conditions. In EV driving tests at speeds of 20–30 km/h, the TMEH presented steady output power up to 5.98 W, capable of driving various loads such as an electronic resistor, Li-ion battery, GNSS/INS device, driving recorder, and cellphone, either with the employment of one or two sets of harvesting coils. The approach of this study offers a promising application scenario to power up numerous electronics on a commercial transport EV platform driven by a more powerful PMSM.