A Method for Determination of Equivalent Circuit Parameters of Piezoelectric Vibration Generator

Abstract

A method for determining parameters of the equivalent circuit of a piezoelectric vibration generator includes fixing one end of piezoelectric vibration generator on vibration source, making the otherend, maintaining constant sinusoidal vibration acceleration amplitude a, and obtaining relation curve between output voltage and vibration frequency of piezoelectric vibration generator under different load resistances RL by sweeping frequency; determining the short-circuit resonant frequency fsc, the static capacitance Cmc, the mechanical quality factor QML, the maximum power value Popt, the resistance value RML, the short-circuit resonant voltage VML ([omega] sc); and calculating the equivalent inductance Lm, the equivalent capacitance Cm, the equivalent resistance Rm, the equivalent input stress VF, the piezoelectric coupling coefficient A and the static capacitance Cmc. The invention can accurately describe the relationship between the output voltage characteristic of the piezoelectricvibration generator and the load, the ambient vibration frequency and the acceleration, and the electric measuring instrument required for measuring is low in cost.

Description

Technical field [0001] The invention relates to the field of vibration environment energy harvesting technology and circuit design, and more specifically, to a method for determining equivalent circuit parameters of a piezoelectric vibration generator. Background technique [0002] Vibration generators can convert vibration energy that exists widely in the environment into electrical energy. The energy conversion methods are divided into three types: electrostatic, electromagnetic and piezoelectric according to the principle of electromechanical conversion. The electrostatic type is realized by the capacitance change of the variable capacitor due to vibration. The most attractive feature of this method is that it has IC compatibility, and can be manufactured by silicon micromachining technology and mass-produced. But in order to realize the voltage restriction or charge restriction on both ends of the capacitor, an independent power supply is required. The electromagnetic type g...

AI Technical Summary

Problems solved by technology

Some existing circuit parameter extraction methods rely on measuring the vibration state of the piezoelectric vibration generator to calculate and determine the parameters, and the required measuring instruments such as Doppler laser vibrometers are expensive

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