Full Spectrum for Rotating Electrical Machines Condition Monitoring and Fault Diagnosis: a Review

The full spectrum is a widely used technique for condition monitoring and fault diagnosis in rotating electrical machines. However, it is known under different names and approaches to analyse both vibration and electrical measurements. The full spectrum allows simultaneous quadrature analysis of periodic signals. For each frequency component of the signals, a direct sequence or positive component and an inverse sequence or negative component can be obtained. In this work, a general and unified description of the full spectrum is carried out. Moreover, the main applications for fault diagnosis through vibration and current analysis are described. Experimental results obtained on the same induction motor are shown to analyse the differences and similarities between the full spectrum of vibrations and electrical variables.