Qiu Chidong, Wu Xinbo, Xu Changqing, Qiu Xiang, Xue Zhengyu
College of Marine Electrical Engineering, Dalian Maritime University, Dalian 116026, China.
Sensors (Basel). 2020 Mar 14;20(6):1631. doi: 10.3390/s20061631.
Fault size estimation is of great importance to bearing performance degradation assessment and life prediction. Until now, fault size estimation has generally been based on acoustic emission signals or vibration signals; an approach based on current signals has not yet been mentioned. In the present research, an approximate estimation approach based on current is introduced. The proposed approach is easy to implement for existing inverter-driven induction motors without complicated calculations and additional sensors, immune to external disturbances, and suitable for harsh conditions. Firstly, a feature transmission route from spall, to Hertzian forces, and then to friction torque is simulated based on a spall model and dynamic model of the bearing. Based on simulated results, the relation between spall size and the multiple characteristic vibration frequencies in friction torque is revealed. Secondly, the multiple characteristic vibration frequencies modulated in the current is investigated. Analysis results show that those frequencies modulated in the current are independent of each other, without spectrum overlap. Thirdly, to address the issue of which fault features modulated in the current are very weak, a fault-feature-highlighting approach based on reduced voltage frequency ratio is proposed. Finally, experimental tests were conducted. The obtained results validate that the proposed approach is feasible and effective for spall size estimation.
故障尺寸估计对于轴承性能退化评估和寿命预测至关重要。到目前为止，故障尺寸估计通常基于声发射信号或振动信号；尚未提及基于电流信号的方法。在本研究中，引入了一种基于电流的近似估计方法。所提出的方法对于现有的逆变器驱动感应电机易于实现，无需复杂计算和额外传感器，不受外部干扰影响，适用于恶劣条件。首先，基于轴承的剥落模型和动力学模型，模拟了从剥落、赫兹力到摩擦转矩的特征传递路径。基于模拟结果，揭示了剥落尺寸与摩擦转矩中多个特征振动频率之间的关系。其次，研究了电流中调制的多个特征振动频率。分析结果表明，电流中调制的那些频率相互独立，没有频谱重叠。第三，为了解决电流中调制的故障特征非常微弱的问题，提出了一种基于降低电压频率比的故障特征突出方法。最后，进行了实验测试。获得的结果验证了所提出的方法对于剥落尺寸估计是可行且有效的。
