Condition monitoring artefacts for detecting winding faults in wind turbine DFIGs
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Condition monitoring artefacts for detecting winding faults in wind turbine DFIGs By (1) School of Electrical and Electronic Engineering, T University of Manchester 1 1 . , . Williamson S Djurovic S 2 2 . , . . Yang W Tavner J P (2) School of Engineering, Durham University
description
Condition monitoring artefacts for detecting winding faults in wind turbine DFIGs. By. (1) School of Electrical and Electronic Engineering, The University of Manchester. (2) School of Engineering, Durham University . Introduction. - PowerPoint PPT Presentation
Transcript of Condition monitoring artefacts for detecting winding faults in wind turbine DFIGs
Condition monitoring artefacts for detecting winding faults in wind
turbine DFIGsBy
(1) School of Electrical and Electronic Engineering, The University of Manchester
11 .,. WilliamsonSDjurovicS22 .,.. YangWTavnerJP
(2) School of Engineering, Durham University
Introduction
• Doubly fed induction generator (DFIG) is the most commonly used type of generator in contemporary large variable speed wind turbines
• One of the most common induction machine faults are winding faults due to short-circuit or open-circuit or abnormal connection of phase windings
• A common fault diagnostic method is the investigation of frequency spectrum content of machine steady state electrical quantities such as current and instantaneous power - non invasive as stator windings are used as search coils.
DFIG modelling for condition monitoring purposes
• Based on coupled-circuit approach
• A circuit is defined as ‘any series connection of coils’
• Coupling inductances are calculated between circuits
• This approach makes it possible to analyze an arbitrarily connected n-phase machine while taking into account higher order field space harmonics
DFIG test rig diagram
SY NCHRO NI ZI NGCO NTACT O R
BACK-TO -BACKCO NVERT ER
AC T EST M ACH I N E(doubly fed I M )
DC M ACH I NE
DC SPEED DR I VE(M ENTO R)
GRI DSUPPLYSTATO R
ROTO R
Test Rig Description
Laboratory test bed(viewed from above)
Test Rig Description
Rotor back-to-back converterDFIG Terminal box
Healthy and faulty DFIG winding configurations used in this presentation
a) Healthy b) Open-circuit DFIG stator winding configuration
Frequency content of predicted DFIG stator line current for healthy and faulty DFIG operation
a) Predicted current spectrum for DFIG operating with healthy windings
b) Predicted current spectrum for DFIG operating with faulty stator windings
0 50 100 150 200 250 300 350 400 450 50010
-4
10-3
10-2
10-1
100
101
Frequency [Hz]
Cur
rent
[A]
280 Hz 380 Hz
0 50 100 150 200 250 300 350 400 450 50010
-4
10-3
10-2
10-1
100
101
Frequency [Hz]
Cur
rent
[A]
115 Hz 215 Hz280 Hz
380 Hz
445 Hz
Frequency content of predicted DFIG total stator instantaneous power for healthy and faulty DFIG operation
a) Predicted power spectrum for DFIG operating with healthy windings
b) Predicted power spectrum for DFIG operating with faulty stator windings
0 50 100 150 200 250 300 350 400 450 50010
-2
10-1
100
101
102
103
104
Frequency [Hz]
Pow
er [W
]
10 Hz
65 Hz
100 Hz
165 Hz
230 Hz
265 Hz
330 Hz 430 Hz
395 Hz 495 Hz
0 50 100 150 200 250 300 350 400 450 50010
-2
10-1
100
101
102
103
104
Frequency [Hz]
Cur
rent
[A]
10 Hz100 Hz
230 Hz
330 Hz
430 Hz
Predicted and measured DFIG stator line current spectra for DFIG operation with stator open-circuit fault
a) Experimental current spectrum b) Predicted current spectrum
0 50 100 150 200 250 300 350 400 450 50010
-4
10-3
10-2
10-1
100
101
Frequency [Hz]
Cur
rent
[A]
115 Hz 215 Hz280 Hz
380 Hz
445 Hz
0 50 100 150 200 250 300 350 400 450 50010
-4
10-3
10-2
10-1
100
101
Frequency [Hz]
Cur
rent
[A]
115 Hz215 Hz
280 Hz 380 Hz
445 Hz150 Hz 350 Hz
Predicted and measured DFIG stator instantaneous power spectra for DFIG operation with stator open-circuit fault
a) Experimental power spectrum b) Predicted power spectrum
0 50 100 150 200 250 300 350 400 450 50010
-2
10-1
100
101
102
103
104
Frequency [Hz]
Pow
er [W
]
10 Hz
65 Hz
100 Hz
165 Hz
230 Hz
265 Hz
330 Hz 430 Hz
395 Hz 495 Hz
0 50 100 150 200 250 300 350 400 450 50010
-1
100
101
102
103
104
Frequency [Hz]
Pow
er [W
]
10 Hz
65 Hz
100 Hz
150 Hz
165 Hz
230 Hz
265 Hz
300 Hz
330 Hz 430 Hz
395 Hz 495 Hz
Conclusions
• A DFIG analytical model was developed and a DFIG test rig built for the purpose of this study
• Research demonstrates that there are harmonic components in DFIG steady state stator current and total power spectra that are directly related to existence of winding fault. These frequencies are slip dependant.
• Simulation data indicate that the power signal spectrum carries more fault specific information when compared to the current signal. Measurement of the power spectrum is however shown to be influenced by high noise levels.
Thank You
