METHOD OF AUTOMATIC CONTROL OF MECHANICAL DAMAGES OF THREE-PHASE ASYNCHRONOUS MOTORS Russian patent published in 2009 - IPC G01R31/00 

FIELD: physics, control.

SUBSTANCE: invention relates electrical engineering and can be used for automatic control of mechanical damages of three-phase asynchronous motors by measuring stator current and analysing its amplitude-frequency characteristic. The proposed method consists in that, during the preset time interval, the motor phase current is recorded, analysed characteristic frequencies are isolated, and the produced signal is converted from analog to the digital form. Then, the spectral analysis of the obtained signal is performed and the amplitudes of current harmonics obtained from the spectral analysis are compared to reference values of harmonics, in characteristic frequency range. Note here that the aforesaid and a set of characteristic frequencies is preset subject to the motor design, type of probable fault. Now, the conclusion on availability of probable fault is made proceeding from the oversized analysed signal compared with reference values.

EFFECT: increase in reliability and selectivity of recognising probable mechanical fault, hence ruling out false operations.

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