Piezoelectric generator equivalent circuit parameter determination method based on electrical signal measurement

Abstract

The present invention discloses a piezoelectric generator equivalent circuit parameter determination method based on electrical signal measurement. The method comprises the steps of: fixing one end ofa piezoelectric generator onto a vibration source, the other end of the piezoelectric generator is free to ensure a constant sinusoidal vibration acceleration amplitude a, performing sweep frequencyto obtain a relation curve of an output voltage of the piezoelectric generator in different load resistances (RL); determining a short-circuit resonant frequency fsc, an open-circuit resonant frequency foc, static capacitance Cmc, a mechanical quality factor Qoc, the maximum power value Popt, a resistance value RML and a short-circuit resonance voltage VML([Omega]sc); and calculating and obtainingvalues of an equivalent inductance Lm, an equivalent capacitance Cm, an equivalent resistance Rm, an equivalent input stress VF, a piezoelectric coupling factor A and a static capacitance Cmc. The piezoelectric generator equivalent circuit parameter determination method can accurately describe the relation of the output voltage of the piezoelectric generator, the load, environmental vibration frequency and the accelerated speed, and the electrical measurement instrument required by the measurement is low in cost.

Description

technical field [0001] The present invention relates to the fields of vibration environment energy collection technology and circuit design, and more specifically, relates to a method for determining equivalent circuit parameters of a piezoelectric generator based on electrical signal measurement. Background technique [0002] Vibration energy harvesting devices can convert the vibration energy widely present in the environment into electrical energy. The energy conversion methods are divided into three types: electrostatic, electromagnetic and piezoelectric according to the different electromechanical conversion principles. The electrostatic type is realized by the capacity change of the variable capacitor due to vibration. The most attractive feature of this method is that it has IC compatibility, and it can be manufactured by silicon micro-processing technology and mass-produced. But in order to realize voltage constraint or charge constraint across the capacitor, indepen...

AI Technical Summary

Problems solved by technology

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

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