Comparative Study of AC-DC Rectifiers for Vibration Energy Harvesters

Energy harvesting systems (EH) have attracted a lot of interest in recent years due to their important role in different applications. Typically, the output of vibrations EH is an alternating current (AC) that requires rectification to supply the electronic load. The rectifier architectures and selection of components have an influence on the energy harvesting system performance in terms of extracted output power and conversion efficiency. In this paper, comparisons between different self-powered rectifier architectures that are composed of diodes and MOSFETs are investigated with simulation and experimental evaluations. This study considers the effect of the load impedance as well as the input voltage levels on the system output power and efficiency. The investigated rectifiers are namely, diode bridge, 4P-MOSFET(4PR), 4N-MOSFET(4NR), 2N-MOSFET-2 diodes (ND), and Negative Voltage Rectifier (NVR). The experimental results show that at 2.5 V input voltage the NVR architecture has the highest output power and efficiency with 119.5 mW and 70.4%, respectively. At 2.5 V of the input voltage, the diode bridge rectifier exhibits an output power of 4S.51mWwhere76.SmW, 6S.93mW, and SO.2 mW are delivered by the 4NR, 4PR, and ND architectures. In terms of conversion efficiency, the diode bridge delivers 40.32 % whereas 4NR, 4PR, and ND architectures show an efficiency of 46.3 %, 44.32 %, and 55.97%, respectively.