تشخیص دقیق شکستگی میله روتور براساس آنالیز مدولاسیون

تشخیص دقیق شکستگی میله روتور براساس آنالیز مدولاسیون

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دانلود مقاله انگلیسی تشخیص دقیق شکستگی میله روتور براساس آنالیز مدولاسیون دو طیفی سیگنالهای جریان موتور

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تشخیص دقیق شکستگی میله روتور براساس آنالیز مدولاسیون

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A new method of accurate broken rotor bar diagnosis based on modulation signal bispectrum analysis of motor current signals

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Motor current signature analysis (MCSA) has been an effective way of monitoring electrical machines for many years. However, inadequate accuracy in diagnosing incipient broken rotor bars (BRB) has motivated many studies into improving this method. In this paper a modulation signal bispectrum (MSB) analysis is applied to motor currents from different broken bar cases and a new MSB based sideband estimator (MSB-SE) and sideband amplitude estimator are introduced for obtaining the amplitude at ð۱۷۲sÞf s (s is the rotor slip and f s is the fundamental supply frequency) with high accuracy.

As theMSB-SE has a good performance of noise suppression, the new estimator produces more accurate results in predicting the number of BRB, compared with conventional power spectrum analysis. Moreover, the paper has also developed an improved model for motor current signals under rotor fault conditions and an effective method to decouple the BRB current which interferes with that of speed oscillations associated with BRB. These provide theoretical supports for the new estimators and clarify the issues in using conventional bispectrum analysis

۱٫ Introduction

Induction motors are the most widely used prime movers in industry. Broken rotor bars (BRB) in motors are a common fault which often brings unexpected breakdowns and leads to loss of productivity. In recent years, this type of fault has been increasingly studied for developing advanced techniques that permit on-line early detection and diagnosis of motor faults to avoid any negative consequences of unexpected shutdowns.

As the main stream technique, signature analysis of motor phase current (MCSA) based on spectrum amplitude, has been widely used to detect BRB and end ring faults. The sideband components at frequency ð۱۷۲ksÞf s have been used to detect such faults, (s is the rotor slip and f s is the supply frequency, and harmonic integer k¼۱, ۲, ۳,… n). In particular, the amplitudes at these sideband components are tested to estimate the number of BRB for diagnosing the severity of the problem.

Although, the MCSA gives acceptable detection results, its diagnostic method on a number of BRBs has not yet had a unified method. As shown in the review papers [1,2] there are more than 5 formulae suggested by different researchers to predict the number of BRB based sideband amplitudes from spectrum analysis.

 

دانلود ترجمه تشخیص شکستگی میله روتور براساس آنالیز مدولاسیون

حجم فایل : ۸۶۲ KB

تعداد صفحه : ۲۹ صفحه

فرمت فایل: PDF

قیمت فایل: ۱۴۵۰۰ تومان