A Study on the Piezoelectric Energy Conversion System using Motor Vibration

This study is focused on the piezoelectric system to use a fixed frequency range from the real motion of motor for implementing wireless sensor network. The energy conversion system is made up of a cantilever beam including a piezoelectric mechanism. The natural frequency of the system is designed near the frequency range of external source. The design parameters are determined by FEM Simulation of stress and strain distribution for various types of the beam configurations. The simulation and experimental results show that the generating power from the trapezoidal configuration is more efficient than that from the rectangular configuration. From the motor vibration (0.3g at 205Hz), the trapezoid energy harvesting module extracts power of 56uW with the load resistance of 800k. Then, a test applicable to the motor demonstrates that the conversed energy can be charged/discharged in a capacitor (22uF). Therefore, it is possible to power motor health monitoring with energy harvesting using motor vibration.