航空发动机叶片柔性抛光技术

Influence of High Frequency Loss on Partial Discharge Pulse Identification of High Voltage Cross Linked Polyethylene Cables

基于发动机叶片结构特点及其抛光工艺要求,为实现叶片型面及阻尼台自动化抛光,满足其型面及进排气边尺寸、粗糙度等质量要求,消除叶片型面波纹对抛光工艺的影响,对砂带柔性抛光工艺装备技术进行研究,提出基于抛光力控制的砂带柔性磨头抛光工艺方法,并对其抛光工艺过程、抛光力控制进行研究,通过对叶片自动化抛光编程及抛光轨迹路径规划技术研究,最终实现发动机叶片高效柔性抛光工艺。抛光试验结果表明,柔性自动化抛光后叶片型面尺寸精度可达±0.06mm,粗糙度低于Ra0.4,与传统手工抛光方法相比,大大提高其抛光效率及表面质量稳定性,降低劳动强度,且减少粉尘污染。

The equivalent bandwidth W-equivalent time length T separation technique is used to identify the partial discharge（PD） pulses by virtue of pulse clusters in the W-T two-dimensional Cartesian coordinate system,however,the high frequency loss of cross linked polyethylene（XLPE） insulated power cable during wave propagation will impair the clusters separation.Consequently,we developed an approximate propagation model to analyze the relation between W,T and PD propagation.While measuring the propagation parameters,this model could overcome the difficulties that propagation time measurement method has limitation of long cables and mathematical analytic solution（MAS） method,hardly measure the long cable.W and T of Gaussian PD pulses and mathematical relation model between W,T and propagation distance were calculated.Moreover,a customized XLPE cable was simulated and measured,and the approximate propagation model and the mathematical relation model were studied.Results show that the propagation loss has less influence on W classification and more influence on T classification.Accordingly,W and T were both efficient for PD separation when the distance between the discharge source and the measurement point was less than 500 m.However,W was more efficient for W-T separation in long distance.