大型旋转体表面风致振动压电能量收集研究

发布时间：2019-04-17 20:01

【摘要】：利用无线传感器节点监测矿井提升系统关键旋转体(滚筒、天轮)的运行状态,是对提升系统典型故障进行检测的新途径,但是传感器节点的寿命短是应用该方法的瓶颈问题。为了满足布置于大型旋转体表面节点供电以及低功耗的要求,本文开展了大型旋转体表面风致振动压电能量收集研究。首先,为了找到适合于大型旋转体工况的压电片安装方式,研究了压电片的固定方式、调整方式对其发电性能的影响;其次,为了对大型旋转体表面上的节点进行供电,设计了一种风致振动压电能量收集装置,并通过实验验证了其可行性;最后,为了降低大型旋转体表面监测传感器节点的功耗,提出了两种高效能量管理策略,并对其进行了对比试验分析。本文完成的具体工作如下:(1)介绍了压电材料的基本理论,为后续的研究做好铺垫。(2)利用软件仿真和实验对压电片在悬臂梁、简支梁两种固定方式下的发电性能进行了分析,讨论了不同固定方式下长宽比、重物块质量等参数对压电片固有频率的影响。结果表明:悬臂梁固定方式适合用于大型旋转体表面风致振动压电能量收集装置。(3)结合大型旋转体的运行工况,设计了一种利用卡门涡街效应的风致振动压电能量收集装置;得出了装置在旋转体转速、阻挡物直径、固定角度等条件下发电电压的变化情况;通过ANSYS软件对压电片进行了受力分析,得出压电片在工作状态下的应力分布情况以及最大应力随不同转速和阻挡物直径变化的情况;根据理论模型及矿井提升机滚筒运动参数搭建了风致振动压电能量收集装置实验台,结合理论分析内容进行了相应实验。结果表明:所设计的能量收集装置在旋转体转速达到145r/min时产生1mW左右的功率输出;相比调整圆柱形阻挡物直径,调整装置的安装角能更加有效地增大能量收集装置的输出功率。(4)分析了大型旋转体表面监测传感器节点的能耗管理需求;提出了基于信号幅值检测的主动式调频策略和适应大型旋转体运行状态的被动式调频策略;通过对比试验,分析了两种调频策略的性能。结果表明:两种策略均可实现功耗管理;在发送频率达50Hz时,被动式调频策略下的节点功耗比主动式调频策略下的功耗小6.8%。
[Abstract]:It is a new way to detect typical faults of hoisting system by using wireless sensor nodes to monitor the running state of the key rotating body (drum, wheel) of mine hoisting system. However, the short life of sensor nodes is the bottleneck problem in the application of this method. In order to meet the requirements of power supply and low power consumption for large-scale rotating body surface nodes, the wind-induced vibration piezoelectric energy collection of large-scale rotating body surface is studied in this paper. Firstly, in order to find the installation mode suitable for large-scale rotating body, the fixed mode of piezoelectric wafer and the influence of adjusting mode on its power generation performance are studied. Secondly, in order to supply power to the nodes on the surface of large-scale rotating body, a wind-induced vibration piezoelectric energy collection device is designed, and its feasibility is verified by experiments. Finally, in order to reduce the power consumption of sensor nodes, two efficient energy management strategies are proposed and compared with each other. The concrete work completed in this paper is as follows: (1) the basic theory of piezoelectric materials is introduced, which lays the groundwork for further research. (2) the piezoelectric wafers in cantilever beams are simulated and experimented with software. The power generation performance of the simply supported beam under two fixed modes is analyzed. The effects of the parameters such as the ratio of length to width and the mass of the heavy mass on the natural frequency of piezoelectric wafers under different fixed modes are discussed. The results show that the cantilever beam fixing mode is suitable for wind-induced vibration piezoelectric energy collection device on the surface of large-scale rotating body. (3) combined with the operation condition of large-scale rotating body, A piezoelectric energy collection device for wind-induced vibration using Karman vortex street effect is designed. The variation of the generator voltage under the conditions of rotating speed, diameter of barrier, fixed angle and so on is obtained. The stress distribution and the maximum stress change with different rotational speed and the diameter of the barrier are obtained through the stress analysis of the piezoelectric chip with ANSYS software. The stress distribution of the piezoelectric piece in the working state and the variation of the maximum stress with different speed and the diameter of the barrier are obtained. According to the theoretical model and the motion parameters of the drum of mine hoist, an experimental platform of wind-induced vibration piezoelectric energy collection device is set up, and the corresponding experiments are carried out in combination with the theoretical analysis. The results show that when the rotational speed of the rotating body reaches 145r/min, the designed energy collecting device can produce the power output of about 1mW. Compared with adjusting the diameter of cylindrical barrier, adjusting the installation angle of the device can increase the output power of the energy collection device more effectively. (4) the energy consumption management requirements of the sensor nodes for large-scale rotary body surface monitoring are analyzed. An active frequency modulation strategy based on signal amplitude detection and a passive frequency modulation strategy adapted to the running state of a large rotating body are proposed, and the performance of the two strategies is analyzed through a comparative test. The results show that both strategies can achieve power management, and when the transmission frequency is up to 50Hz, the node power consumption of passive FM strategy is 6.8% less than that of active FM strategy.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD633

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