感应电动机正常使用时一般具有长寿命高可靠性,为在较短时间内预测感应电动机的寿命,提出了一种简单易行的感应电动机加速退化试验方法:在电动机转轴上偏心安装圆孔叶片模拟电动机负载工作时承受的不平衡载荷,并且通过改变叶片偏心安装孔的位置模拟增大不平衡载荷.进行了3种应力形式的试验研究,以试验中测得的电动机轴心轨迹面积值表征电动机的性能退化指标,建立了轴心轨迹面积相对变化的漂移Brown运动和幂律加速退化模型,利用无偏估计法和最小二乘法得到模型参数的估计,外推获得叶片无偏心安装状态下的不平衡重力矩,以该值作为电动机正常工作时承受的不平衡载荷,预测和分析了电动机正常工作寿命和可靠性,验证了加速退化试验方法的可行性和高效性.%Induction motors have a long life and a high reliability in service at normal working conditions. To predict the life of motors in a short period of time, one simple and available accelerated degradation testing method is presented. To simulate the unbalanced load stressing on the motors, the lamina with some circular holes is easily mounted on the shaft of the motor eccentrically, and simulate different unbalanced load by changing the mounted places of the lamina. A motor accelerated test with 3 kinds of stresses is applied, and the Orbit Areas of the shafts to reveal the performance degradation index of the motors are obtained. Linear drift Brownian motion and Power Law model are used to analyze the relative ratios of the Orbit Areas, and the estimates of the model parameters are solved by the unbiased estimates methods and the least squares methods. With a balanced lamina mounted on the shaft as normal working condition of the motors, the life and reliability are predicted and evaluated by using the extrapolated unbalanced gravity moment and the estimates of the model parameters, and the accelerated degradation testing method has been proven to be practical and efficient to predict the life of the motors.
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