Performance study of piezoelectric energy harvester for vertical shaft hoisting system

For the characteristics of irregular low-frequency and broad-frequency vibration in the operation of the cage of vertical shaft hoisting system, a variable-section bending beam piezoelectric vibration harvester is proposed to broaden the operating band of the harvester and improve the energy collection efficiency of the harvester for irregular low-frequency and broad-frequency vibration in the vertical shaft hoisting system. The structural finite element analysis of the harvester was carried out, and the experimental test platform was built. Based on simulation and experiment, the difference of the power generation performance between the harvester and the trapezoidal beam and the traditional rectangular beam was explored, and the energy supply test was carried out with the energy harvester. The results show that the strain of the beam is more uniform and the overall output response of piezoelectric material is better. At the same time, the resonance frequency is low, the open circuit output voltage is high, and there are many obvious peak values, which can effectively realize the broadening of acquisition frequency band. When the end bending angle of the piezoelectric vibrator is 40°, and the additional mass is 2.14 g, the maximum load output voltage of the harvester is 34.4 V and the maximum output power can reach 14.7 mW under the standard energy interface circuit and the optimal load resistance is 80 kΩ. The power supply test of the wireless node verifies its energy conversion efficiency and feasibility of energy supply, which can meet the power supply requirements of the wireless low-power sensor for mining.