Faults diagnosis of three-phase induction motors using envelope analysis

Diagnosis of Three-Phase Electrical Machines Using Multidimensional Demodulation Techniques

“…Applications to failure detection are available in [7], [14], and [20]- [27]. Interestingly, for a balanced system, it has been shown in [14], [21], [22], [24], and [28] that the Concordia transform (CT), which has been used for failure detection purposes in [14], [21]- [24], and [28]- [38], can also be interpreted as a demodulating tool. As compared to classical demodulation tools, CT exhibits interesting properties such as lower complexity and lack of end effect problems or other artifacts [28].…”

“…In the literature, many criteria and/or techniques have been proposed to perform this task. In [14], [21], [22], [24], [25], and [29], failure severity is measured through statistical criteria. However, these criteria require knowledge of the fault frequencies, which also depend on other parameters (speed or slip information).…”

Rotor Cage Fault Detection in Induction Motors by Motor Current Demodulation Analysis

“…The AM current appears in stator current as an envelope of this current - Fig.5. Therefore the amplitude demodulation is known as an envelope analysis (Jaksch, 2003). It is the base for dynamic rotor fault diagnostics.…”

“…In this case the additional recomputation coefficient between phase currents and transformed currents does not have to be used. Space transform was firstly also used for the demodulation (Jaksch, 2003). From the viewpoint of the means necessary for the demodulation process, space vector P(t)=id(t)+jiq(t) represents a complex analytical signal computed from three three currents ia, ib, ic similarly like the Hilbert transform creates the artificial complex signal H(t) from one phase current.…”

Condition Monitoring of Induction Motors Based on Stator Currents Demodulation

“…Typical examples include broken rotor bars [18][19][20][21][22], gearbox faults [23] and bearing faults [7], [14], [17], [24]. In order to perform currents demodulation, several authors have employed classical demodulation techniques such as the synchronous demodulator [22], [25][26], the Hilbert transform [18][19][20], [22], [27], timefrequency distributions [14], [17], [28][29][30] or adaptive tracking of sine waves [31]. Joint IA-IF estimation based on the Concordia transform is investigated in [7], [21], [32].…”