Aswathi Poozhikkuth | Calicut University (original) (raw)

Uploads

Papers by Aswathi Poozhikkuth

Research paper thumbnail of A review of induction motors signature analysis as a medium for faults detection

Industrial Electronics, IEEE …, Jan 1, 2000

This paper is intended as a tutorial overview of induction motors signature analysis as a medium ... more This paper is intended as a tutorial overview of induction motors signature analysis as a medium for fault detection. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of motor signature analysis for the detection and the localization of abnormal electrical and mechanical conditions that indicate, or may lead to, a failure of induction motors. The paper is focused on the so-called motor current signature analysis which utilizes the results of spectral analysis of the stator current. The paper is purposefully written without "state-of-the-art" terminology for the benefit of practicing engineers in facilities today who may not be familiar with signal processing.

Research paper thumbnail of Detection of Broken Rotor Bars In Induction Motor Using Starting-Current Analysis and Effects of Loading

Electric Power …, Jan 1, 2006

This paper studies the detection of broken rotor bars in induction motors. The hypothesis on whic... more This paper studies the detection of broken rotor bars in induction motors. The hypothesis on which detection is based is that the apparent rotor resistance of an induction motor will increase when a rotor bar breaks. Here, the apparent rotor resistance is that in the balanced steady-state single-phase electricol model of an induction motor. To detect broken rotor bars, measurements of stator voltage, stator current, stator excitation frequency, and rotor velocity are taken over a small range of velocity. These measurements are processed by a near-leastsquare-error estimator to produce estimated motor states and parameters. In particular, rotor resistance is estimated and compared with its nominal value to detect broken rotor bars. As part of this estimation process, it is necessary to compensate for the thermal variation in rotor resistance. The broken-rotor-bar detector is evaluated experimentally using one stator and three rotors from identical 3-hp induction motors. In one rotor, a bar is broken by milling into the rotor. The apparent rotor resistance, as estimated, is clearly greater for the rotor with the broken bar.

Research paper thumbnail of A method to detect broken bars in induction machine using pattern recognition techniques

Industry Applications, IEEE …, Jan 1, 2006

In this paper, a pattern recognition (PR) method is used to provide the tracking and the diagnosi... more In this paper, a pattern recognition (PR) method is used to provide the tracking and the diagnosis of a system. First of all, from measurements carried out on the system, features are extracted from current and voltage measurements without any other sensors. These features are used to build up a pattern vector, which is considered as the system signature. Then, a feature selection method is applied in order to select the most relevant features, which define the representation space. The decision phase is based on the "k-nearest neighbors" (knn) rule, associated with an evolution tracking of system using trajectory allowing a diagnosis not only of states defined in the training set, but also of the intermediate states. The appearance of a new operating mode is taken into account in order to enrich the initial knowledge base and thus to improve the diagnosis. This approach is illustrated on asynchronous motor of 5.5 kW with squirrel cage, in order to detect broken bars under any load level. The experimental results prove the efficiency of PR methods in condition monitoring of electrical machines.

Research paper thumbnail of Methods of motor current signature analysis

Electric Power Components and Systems, Jan 1, 1992

... The background for this application derives from several areas mong which are the very extens... more ... The background for this application derives from several areas mong which are the very extensive experience of vibration and signature analysis in mechanical systems, modem control theory, and motor fault analysis. This paper ...

Research paper thumbnail of Current signature analysis to detect induction motor faults

Industry Applications Magazine, …, Jan 1, 2001

... 5) Open circuit in one: phase (single-phasing) motor may continue to operate, depending on th... more ... 5) Open circuit in one: phase (single-phasing) motor may continue to operate, depending on the load condition (eg ... Prewarning of motor failure, such as in 3) and 4), can only be achieved if shorted turns ... to diag-nose the faults stated in 1) and 2) for low-voltage induction motors. ...

Research paper thumbnail of A review of induction motors signature analysis as a medium for faults detection

Industrial Electronics, IEEE …, Jan 1, 2000

This paper is intended as a tutorial overview of induction motors signature analysis as a medium ... more This paper is intended as a tutorial overview of induction motors signature analysis as a medium for fault detection. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of motor signature analysis for the detection and the localization of abnormal electrical and mechanical conditions that indicate, or may lead to, a failure of induction motors. The paper is focused on the so-called motor current signature analysis which utilizes the results of spectral analysis of the stator current. The paper is purposefully written without "state-of-the-art" terminology for the benefit of practicing engineers in facilities today who may not be familiar with signal processing.

Research paper thumbnail of Detection of Broken Rotor Bars In Induction Motor Using Starting-Current Analysis and Effects of Loading

Electric Power …, Jan 1, 2006

This paper studies the detection of broken rotor bars in induction motors. The hypothesis on whic... more This paper studies the detection of broken rotor bars in induction motors. The hypothesis on which detection is based is that the apparent rotor resistance of an induction motor will increase when a rotor bar breaks. Here, the apparent rotor resistance is that in the balanced steady-state single-phase electricol model of an induction motor. To detect broken rotor bars, measurements of stator voltage, stator current, stator excitation frequency, and rotor velocity are taken over a small range of velocity. These measurements are processed by a near-leastsquare-error estimator to produce estimated motor states and parameters. In particular, rotor resistance is estimated and compared with its nominal value to detect broken rotor bars. As part of this estimation process, it is necessary to compensate for the thermal variation in rotor resistance. The broken-rotor-bar detector is evaluated experimentally using one stator and three rotors from identical 3-hp induction motors. In one rotor, a bar is broken by milling into the rotor. The apparent rotor resistance, as estimated, is clearly greater for the rotor with the broken bar.

Research paper thumbnail of A method to detect broken bars in induction machine using pattern recognition techniques

Industry Applications, IEEE …, Jan 1, 2006

In this paper, a pattern recognition (PR) method is used to provide the tracking and the diagnosi... more In this paper, a pattern recognition (PR) method is used to provide the tracking and the diagnosis of a system. First of all, from measurements carried out on the system, features are extracted from current and voltage measurements without any other sensors. These features are used to build up a pattern vector, which is considered as the system signature. Then, a feature selection method is applied in order to select the most relevant features, which define the representation space. The decision phase is based on the "k-nearest neighbors" (knn) rule, associated with an evolution tracking of system using trajectory allowing a diagnosis not only of states defined in the training set, but also of the intermediate states. The appearance of a new operating mode is taken into account in order to enrich the initial knowledge base and thus to improve the diagnosis. This approach is illustrated on asynchronous motor of 5.5 kW with squirrel cage, in order to detect broken bars under any load level. The experimental results prove the efficiency of PR methods in condition monitoring of electrical machines.

Research paper thumbnail of Methods of motor current signature analysis

Electric Power Components and Systems, Jan 1, 1992

... The background for this application derives from several areas mong which are the very extens... more ... The background for this application derives from several areas mong which are the very extensive experience of vibration and signature analysis in mechanical systems, modem control theory, and motor fault analysis. This paper ...

Research paper thumbnail of Current signature analysis to detect induction motor faults

Industry Applications Magazine, …, Jan 1, 2001

... 5) Open circuit in one: phase (single-phasing) motor may continue to operate, depending on th... more ... 5) Open circuit in one: phase (single-phasing) motor may continue to operate, depending on the load condition (eg ... Prewarning of motor failure, such as in 3) and 4), can only be achieved if shorted turns ... to diag-nose the faults stated in 1) and 2) for low-voltage induction motors. ...