Ferromagnetic Vibrating Micro-vibration Generating Device Research

With the rapid development of era, energy problem stand out increasingly, and exploring and getting all sorts of new energy is becoming the mainstream of today. The technology of power generator based on micro-scale vibration has been a hot in the world. Main problem of this research is to develop the power generator which converts the vibrational energy into electrical energy has a long usetime in real life.This thesis mainly studies the working state of power generation unit of ferromagnetic vibration generator and the influence of distributed capacitance and impedance of the coil.According to the magnetic circuit theorem, we know that changing the magnetic will cause the change of the effective magnetic permeability of the magnetic circuit. This is known as the displacement variable permeability. Free ferromagnetic micro-vibration generating device mainly use the effect of displacement variable permeability. Collecting the induced current can get electricity.Firstly, we analyses the output voltage of generating model theoretically. We put vibrator as forced vibration approximately. According to the forced vibration equation and Faraday’s law of electromagnetic induction, we can get the expression of voltage theoretically. Using matlab to simulation, we concluded the change rules that voltage with the coil number of turns. The rules and results are in agreement with the experiment basically.The design of induction coil affects the efficiency of electric energy collection, so we study the coil part of the device in detail. The frequency characteristic, the number of turns and winding mode dependent capacitor of the coil, and the impedance versus number of turns of hollow coils have been measured, respectively. The distributed capacitance has been observed almost irrelevant to the number of turns and the winding ways of the coils when the number of turns is greater than10. By measuring the magneto-capacitance effect of spiral coil, it was found that the distributed capacitance of coil relates to the coil material, suggesting the influence of skin effect. From the coil equivalent circuit, combining with the skin effect, an approximate formula of distributed capacitance and impedance have been worked out. Analysis showed that the distributed capacitance of coil mainly originates from line capacitance and the capacitance between turns.The free ferromagnetic micro vibration generating device can work in the condition of the low frequency vibration, micro dynamic, and has the very high application prospect. In addition, the study of the distributed capacitance and impedance of spiral coil fill the void in distributed capacitance field.