Introduction of a Novel Vector Approach to Detect Rotor Electrical Faults in Induction Motors

Although induction motors are robust devices, faults may appear and so reliable and stable operation is required. More aspects need to be addressed nowadays in terms of condition monitoring. It is necessary to extract as much information as possible related to the overall motor condition and health. Also, different levels of diagnosis are required, as well necessity of detecting the fault level severity and avoiding false positive/negative alarms. This paper presents a new method to detect broken rotor bars in induction motors using a new vector approach. This new vector is a function of the zero-sequence current and any of the three phase stator currents. It is revealed that the time-representation of this vector offers reliable diagnostic alarm of rotor electrical faults. Moreover, the frequency spectrum of the proposed vector’s modulus can be studied and analysed to extract more information regarding the fault severity level.