1-doble ppt motor

Parmatma Dubey, CG Global R&D Centre, Crompton Greaves, Mumbai, India +91-22-67558525, 9867154107. E-mail: [email protected]

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A STUDY OF DIFFERENT SIGNATURESBY SIMULATING FAULT CONDITIONS

IN INDUCTION MOTOR

Parmatma Dubey, A. L. HangalCG Global R&D Centre

Crompton Greaves Ltd. Mumbai


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Highlights

• Major modes of failure in motors• Test rig for fault study• Simulation of

Bearing fault Inter-turn shortPhase to phase shortEnd ring fault

• Web based Condition Monitoring System


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Major Type of Failures in Rotating Machines


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Test-rig

Current Clamp


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Fault Detection Methodology

Bearing Defect Prediction: Calculation of Bearing Defect Frequency


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Bearing Defect(By Mechanical Vibration)

Bearing Defect Prediction: Calculation of Bearing Defect Frequency(e.g. for 6306 bearing)

No. of Balls/Rollers, Nb = 8 RPM, N = 1485 Rotor Frequency, Fr = 24.75 Hz Pitch Diameter, Dc = 52 mm Ball/Roller Diameter, Db = 12.303 mm Contact Angle, β = 0Outer Race Fault Frequency, f0 = 75.58 Hz

Reported Kurtosis Value: 4.1

Expected Kurtosis Value: 3.0


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Bearing Defect(By Motor Current Signature Analysis)

Bearing Defect Prediction: Calculation of Bearing Defect Frequency(e.g. for 6306 bearing)

Outer Race Fault Frequency, F0 = |f1 ± m* fo| = 124.83 Hz.

Motor current signature for bearing fault.


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Stator Winding: Phase to Phase Short


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Rotor Fault: End ring crack

For a 4-pole motor,

RPM at full load = 1440Supply line frequency, f1 = 49.25 HzSynchronous speed = (120*f) / P = 1477.5Slip, s = 0.02538Side band frequency about supply line frequency can be given by

fsb = f1(1±2*s) Hz.fsb = 51.75, 46.70 Hz.

Motor current signature for end ring fault


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WEB BASED CONDITION MONITORING SYSYTEM

Configuration of Web Based Condition Monitoring System

• This programme has been developed for remote monitoring of the machine.

• The computer programme has been developed using National Instruments’ LabView software.

• Host software has a user friendly graphical user interface to remotely monitor the test status

• All fault diagnostics logics have been included in the web based programme which measures and displays the condition of the motor situated at a remote location


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WEB BASED CONDITION MONITORING SYSYTEM

Front panel and connection status with data acquisition unit and the central server

• Test panel shows overall condition of the machine

• Time and frequency series plots of vibration and current can be seen in separate windows

• Alarm level (cut-off amplitude/frequency) is set for all parameters.

• A report describing overall condition of the machine can be sent to the customer in a word doc. format.


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1-doble ppt motor

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