定子电流二次方法的异步电机转子复合故障诊断

Rotor Composite Fault Diagnosis in Asynchronous Motor Using the Square Calculation of Stator Current

为了突出故障早期的故障特征信息,避免复杂算法,实现故障早期状态在线监测,提出定子电流二次方法(流方)的笼型异步电机转子复合故障检测。定子电流经过二次方后转移和放大了定子电流中的故障信号,由于转子断条和气隙偏心的故障特征频率在频谱分布上的差距,转子复合故障得到分离和辨识。同时比较了单相流方和三相总流方对复合故障的诊断效果。复合故障时,流方的故障频率不是单一故障频率的直接累加,还包括两故障频率所引起的交叉干扰项。实验表明,随着断条数的增加,复合故障中表征断条的故障特征分量的幅值增加,有利于故障程度的量化和诊断系统的建立。

In order to highlight the fault characteristic components and avoid complex algorithms, on-line monitoring of squirrel cage asynchronous motor initial fault is achieved. Rotor composite faults diagnosis of motor based on the square calculation of stator current is proposed. The fault signal of the stator current is transferred and amplified because of the squared stator current. The fault characteristic frequency components of broken bar and rotor eccentricity are different in spectrum distribution, so the rotor composite fault is separated and identified. At the same time, the diagnosis effects of one-phase squared current are different from those of three-phase squared current. The composite faults frequency is not the sum of two single fault directly, but takes into account the cross interference caused by two kinds of fault frequency. Experiments indicate that the amplitude of 2sf1 for the rotor composite fault increases with increasing broken bar, which is beneficial to the quantification of the fault extent and establishment of diagnostic rules.