Stabilizing Supercapacitor Voltage of a Novel Electromagnetic Damper for Enhanced Vibration Control Performance and High Energy Harvesting Efficiency

Energy harvesting electromagnetic dampers (EH-EMDs) are recognized for their potential to combine energy recovery with vibration control. However, the effect of energy harvesting circuit parameters on damper performance remains underexplored. This article investigates how circuit parameters and types impact the performance of EH-EMDs. Our theoretical analysis reveals that supercapacitor voltage is crucial for determining the adjustable damping range and energy efficiency in traditional single dc–dc converter-based EH-EMDs. To address supercapacitor voltage instability, we propose a two-stage cascaded dc–dc converter-based electromagnetic damper (TCDC-EMD) system that improves both vibration control and energy harvesting. The TCDC-EMD consists of an electromagnetic motor, a bridge rectifier, two dc–dc converters, a supercapacitor, and a battery. The first converter regulates damping force, while the second stabilizes the damping controllable range and energy efficiency. We also develop an integrated control system for a half-car suspension to ensure precise closed-loop damping force tracking and stable supercapacitor voltage. Experimental results show that the TCDC-EMD system outperforms a single converter-based EH-EMD, with vertical vibration and harvested energy increasing by 14.26% and 19.29%, respectively. The system achieves self-powering for its control circuit and an overall energy efficiency of 70.82%, demonstrating great practical potential.