امكان سنجي استفاده از حسگرهاي پيزوالكتريك در پايش وضعيت ماشين هاي الكتريكي

چكيده انگليسي :

Feasibility Study of using Piezoelectric Sensors for Condition Monitoring of Electrical Machines Hosein Movahedian Attar h movahedian@ec iut ac ir December 01 2014 Department of Electronic and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Dr Ahmadreza Tabesh a tabesh@cc iut ac ir Abstract This thesis investigates the application of various types of piezoelectric materials including piezocrystalline and piezo polymers in condition monitoring of electric machines The condition monitoring is aprocedure for detection of defects and failures in mechanical and electrical parts of an electric machine whichcan prevent severe damages to the structure machine by early detection of the failures Piezoelectricmaterials are among smart materials which are sensitive to mechanical strain and they can generate electricdue to the mechanical vibration Thus despite passive strain and accelerometer sensors a piezoelectricvibration sensor does not need an extra power source as a bias for sensing vibrations This feature enablesusing piezoelectric materials as a self power sensor in remote and wireless sensing applications Currently the induction machines are horse power of various industries and the condition monitoring ofthese machines due to vast amount of their applications in recent decades is among demanding researchtopics Condition monitoring of an electric machine is conventionally established based on processing of the signalsof the vibration sensors in frequency domain Owing to the recent advances in microelectronics indevelopment of high speed and inexpensive processors discrete signal processing DSP algorithms can nowbe readily implemented within the DSP boards The condition monitoring algorithms are often realized basedon digital processing of captured signals from accelerometers and vibration sensors Thus the sensitivity ofsensors to vibration and the signal to noise ratio of sensors are significantly important in fast and accuratedetection of failure in electric machines In this thesis firstly the suggested processing algorithms for condition monitoring are reviewed and themost suitable methods which can be used for piezoelectric sensors are selected Then various piezoelectricsensors for this application are practically investigated Since the investigation of the piezoelectric sensorsneeds the model and characterization of the sensors a vibration test bed is developed that mainly includes acomputer controlled vibration plate with electromagnetic vibration exciter The vibration test setup isequipped with an accelerometer sensor which is used for characterizing various piezoelectric sensors Then after characterizing the piezoelectric sensors the application of these sensors are investigated using anexperimental test setup for condition monitoring of the electrical induction machines In these tests theperformance of polymer and crystalline types of piezoelectric sensors in detection of bearing defections inelectric machine are investigated The test results show that piezo polymer sensors due to flexibility and easeof installation as well as high signal to noise ratio are among promising sensors for condition monitoring ofelectric induction machines Key words Condition monitoring induction machines piezoelectric sensors sensorcharacterization test bed shaker

موحديان عطار، حسين

امكان سنجي استفاده از حسگرهاي پيزوالكتريك در پايش وضعيت ماشين هاي الكتريكي

پايش سلامت سازه ها , لرزش سنج , ميز لرزاننده , عيب يابي ماشين الكتريكي دوار , تبديل فوريه