تشخيص عيب اتصالي حلقه هاي سيم پيچي استاتور موتورهاي القائي در شرايط عدم تعادل ولتاژ تغذيه

چكيده انگليسي :

99Stator Winding Turn Fault Detection of Induction Motors in Unbalanced Supply Voltage Condition Rasool sharifi r sharifi@ec iut ac ir Date of Submission 2009 05 20 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Ebrahimi mebrahim@cc iut ac irAbstractCondition monitoring of operating equipments with diagnosis of faults in incipient stages and preventing offailure leads to very less repair cost less damage due to shut down and increase in reliability that speciallyin expensive and vital applications is very important On the other hand favorite characteristics of inductionmotors cause to it contain majority use Stator faults consist of winding and core faults that usually start frominter turn short circuits in second place contain 30 40 of all electrical machine faults There are severalmethods for detecting this fault but main problem of these methods is sensitivity to nonideal conditions suchas supply voltage unbalance Among these is motor current signature analysis that due to its noninvasive andeasy implementation has very usage Motor current spectrum analysis in stator winding fault condition leadsto this result that rotor slot harmonics are increased But these harmonics have the same response tounbalanced supply voltage In this project early purpose is current spectrum analysis in faulty condition that the reason of rotor slotharmonics is specified Then research for the same effect of supply voltage unbalance on them that thedifference of short circuit from this condition is determined And the final purpose is developing a methodthat able to detect inter turn short circuit in voltage unbalance condition Therefore in early very some stator winding fault diagnosis methods are introduced Fault indicator characteristics and problems are presented and then the methods are evaluated So for modeling of theinduction motor in faulty condition machine equations consist of rotor and stator voltage mechanical andshort circuited coil equation are developed Also winding function approach for calculating of theinductances is used Then for analyzing of the motor current spectrum rotor and stator space harmonics ofmagnetomotive force are introduced and with simulation results the spectrum of motor current in healthy andfaulty conditions is analyzed Rotor slot harmonics are introduced and are showed that the magnitude ofsome of them increase in faulty and unbalanced voltage condition In continue a new method for stator wingfault diagnosis in unbalanced supply voltage condition based on three phase current spectrum analysis isproposed In the end after describing of prepared setup experimental results are presented Experiments are done in noload and load condition healthy and tow short circuit mode and three value of voltage unbalance factor totally 18 experiments The results showed that implemented short circuit is light and in fact there is incipientstage Then three phase current spectra in healthy faulty and unbalanced voltage conditions are showed Atthe end proposed fault indicator is calculated using measured spectra and its ability to detect the inter turnstator winding short circuit in balanced and unbalanced voltage is showed Keywords Induction Motor Stator Winding Turn Fault Fault Diagnosis Conditionmonitoring Motor Current Signature Analysis MCSA Unbalanced SupplyVoltage

شريفي، رسول

تشخيص عيب اتصالي حلقه هاي سيم پيچي استاتور موتورهاي القائي در شرايط عدم تعادل ولتاژ تغذيه

پايش وضعيت , تحليل طيف جريان سه فاز , هارمونيك فضائي استاتور