Diagnosis apparatus and methof for broken rotor bar in induction motors

The objective of the present invention is to provide a device and a method for diagnosing failure of a rotor in an induction motor, capable of improving more accurate and simple diagnosis performance by predicting multiple failure indexes and diagnosing failure depending on the number of various failure indexes obtained through unique value prediction using an estimation of signal parameters via rotation invariance techniques (ESPRIT) which is more accurate and less complicate than an MUSIC technique in the existing techniques for predicting a unique value to diagnose failure of a rotor in an induction motor. Furthermore, the present invention is aimed to provide a device and a method for diagnosing failure of a rotor in an induction motor, capable of perfectly diagnosing failure by analyzing the unique value using a minimum description length (MDL) technique in case that the load ratio is small in the induction motor and using the number of signal unique values having the bigger size than noise unique values as a new failure index.