SQUIRREL-CAGE ASYNCHRONOUS MOTOR AND FAULT-DETECTION METHOD THEREFOR

摘要

The invention relates to a method of detecting damage caused to the short-circuit rings and/or bars of the rotor cage of squirrel-cage asynchronous motors, regardless of the type of load used thereby. In this way, the inventive method can detect said type of faults even when the motor is operating with loads comprising a resistant torque with an oscillating or pulsating component. According to the invention, broken bars produce a significant alteration in the length spanned by each pole over the air gap of the machine and said alteration constitutes the parameter that is used as a fault detection indicator. Variations in the length of the magnetic poles are detected by measuring the flux linkage at one of the stator teeth (4), using an auxiliary winding (5) which is disposed in said stator tooth (4). The invention also relates to a squirrel-cage asynchronous motor comprising an auxiliary winding (5) which can be used to detect damage caused to the short-circuit rings and/or bars of the cage under any type of load.