Equivalent Resistance Control for Maximum Power Transfer Method of Piezoelectric Element in Vibration Power Generation

This paper proposes a novel equivalent resistance control for maximum power transfer method of piezoelectric element in vibration power generation. In the proposed method, the rectified voltage and current of a diode rectifier are in phase by the boost chopper. Thus, the input side of the boost chopper behaves as a resistor equivalently. For maximizing the generated power of the piezoelectric element, this resistance must be controlled to the internal impedance of the piezoelectric element by the law of the maximum power transfer. The basic principle of the proposed method is discussed, and then confirmed by computer simulation using Piece-wise Linear Electronical Circuit Simulation (PLECS). Simulation results demonstrate that the output power at buck chopper is 7.36 mW by the proposed method. This output power with the proposed method is 3.5 times greater than the output power without the proposed method.