TABLE OF CONTENTS
1 INTRODUCTION ...……….. 3
2 OBJECTIVE AND SCOPE OF RESEARCH ...………… 12
3 THEORETICAL BACKGROUND ...…………. 14
3.1 FUNDAMENTALS OF OMAX...….. 14
3.2 FUNDAMENTALS OF NARX ...….. 17
3.2.1 Application of NARX in modelling and diagnostics ... 19
4 LABORATORY TEST STAND DESCRIPTION ...…………. 23
5 EXPERIMENTAL RESULTS ...…………. 25
5.1 OMA(X) EXPERIMENTAL RESULTS ...….. 25
5.1.1 Comparison of OMA and OMAX method for eddy-current sensors ... 25
5.1.2 Comparison of OMA and OMAX method for accelerometers ... 27
5.1.2.1 Data pre-processing ... 29
5.1.2.2 Analysis with the application of the OMA method ... 29
5.1.2.3 Analysis with the use of the OMAX method ... 31
5.1.2.4 Comparison of results ... 32
5.1.2.5 Final remarks ... 34
5.1.3 Investigation if load change is sufficient excitation for OMAX ... 35
5.1.4 Investigation if electromagnetic exciter is sufficient excitation for OMAX ... 37
5.1.4.1 Description of electromagnetic exciter ...…. 37
5.1.4.2 Experimental results ...…. 41
5.2 SHM USING OMA(X) METHOD ...…. 42
5.3 NARX EXPERIMENTAL RESULTS ...…. 49
6 BLADE CRACK DETECTION...………….. 52
6.1 OMA(X) METHOD ...….. 52
6.1.1 Proposed diagnostics algorithm ... 52
6.1.2 Experimental results ... 54
6.2 OMAX RESULTS WITH USING OF ELECTROMAGNETIC EXCITER ...….. 57
6.3 NARX EXPERIMENTAL RESULTS ...….. 59
7 VERIFICATION OF PROPOSED DIAGNOSTIC ALGORITHMS ON REAL DATA .. 61
7.2 OMA RESULTS ...……. 64
8 SPECIFICATION OF ON-LINE TURBINE MONITORING SYSTEM...……… 66
8.1 MONITORING SYSTEM BASED ON OMA(X) METHOD ...…… 66
8.1.1 System architecture ... 66 8.1.2 Input signals ... 67 8.1.3 Output signals ... 69 8.1.4 Diagnostics algorithm... 70 8.1.5 User interface ... 72 8.1.6 System configuration ... 75
8.2 MONITORING SYSTEM BASED ON NARX METHOD ...……. 76
8.2.1 System architecture ... 76 8.2.2 Input signals ... 77 8.2.3 Output signals ... 78 8.2.4 Diagnostics algorithm... 79 8.2.5 User interface ... 80 8.2.6 System configuration ... 82
9 CONCLUSION AND FINAL REMARKS ...……… 83
10 REFERENCES ...………….. 85
11 NOMENCLATURE ...………….. 93
12 LIST OF ABBREVIATIONS ...………….. 94
13 LIST OF FIGURES ...…………. 95