电动拖拉机变刚度振动馈能装置频率匹配方法与试验

Frequency Matching Method and Experiment of Variable Stiffness Vibration Energy Feedback Device for Electric Tractor

摘要:

针对轮式电动拖拉机的高效振动能量回收问题，在课题组现有振动馈能装置的基础上，引入变刚度弹簧，提出一种装置共振频率与路面激励频率的匹配方法，提升了俘能性能。分析电动拖拉机行驶的路面激励频带，研究并建立变刚度振动馈能装置的动力学模型；融合隐式重启Arnoldi法、自适应交叉近似算法及有限元方法研究装置的模态演化规律，在此基础上确定变刚度弹簧的劲度系数，提出变刚度振动馈能装置的频率匹配方法；通过谐波定频与扫频试验对比，研究定、变刚度振动馈能装置的俘能性能。结果表明：引入变刚度弹簧能够使馈能装置的共振频带拓宽，最大瞬时输出电压提高至52.2V，平均输出功率和发电量分别提升34.4％和42.8％，同时满足电池组的减振要求。

Abstract:

In allusion to the efficient vibration energy recovery problem of a wheeled electric tractor, a variable stiffness spring was innovatively integrates into the research team’s existing vibration energy feedback device and a method was proposed to match the device’s resonance frequency with the road surface excitation frequency, thereby improving energy capture performance. Firstly, the range of road excitation frequency was analyzed based on the road grade and vehicle speed of the electric tractor. Subsequently, a nonlinear 10-degree-of-freedom dynamic model of the variable stiffness vibration energy feedback device was formulated. With the QR decomposition, implicit restart Arnoldi method (IRAM) and adaptive cross approximation algorithm (ACA), the modal frequencies of the device were solved, and the modal evolution law was analyzed by combining these methods with the finite element method. On this basis, the stiffness coefficient of variable stiffness spring was determined, and the frequency matching method for the variable stiffness vibration energy feedback device was proposed. Finally, fixed-frequency and swept-frequency bench tests were conducted to compare the energy capture performance of the fixed and variable stiffness vibration energy feedback devices. The results demonstrated that the variable stiffness spring structure significantly broadened the resonance band of the device, increased the maximum instantaneous output voltage to 52.2V, and boosted the average output power and electricity generation by 34.4% and 42.8%, respectively，at the same time, it met the vibration reduction requirement for the battery pack. The above research can provide theoretical and technical support for the power supply of electric tractors and it was of great significance to promote the development of its energy-saving technology.