Abstract: Focusing on the vibration energy harvesting system (VEHS) of the energy harvesting type ultrasonic motor (EH-USM), the equivalent circuit model and the energy flow chart of the VEHS are established, the energy constitute and the charge-voltage locus under different interface topology circuits are also derived. The harvesting energy, dissipating energy and extracting energy of the VEHS under different interface topology circuits are quantitatively studied. Simulations are performed to exhibit the effects of the rectified voltage factor, the conduct voltage drop factor of the diode, the voltage conversion factor and the electromechanical coefficient on the harvesting energy, the dissipating energy and the extracting energy. The validity of the numerical results is testified by the experiments. Research results have shown that a larger electromechanical coefficient and a smaller voltage conversion factor as well as the conduct voltage drop factor of the diode are benefit to improve the harvesting output performances.

Key words: energy flow chart, interface circuit, ultrasonic motor, vibration energy harvesting