Investigation of Parallel Misalignment Faults of Induction Motor by Using Entropy Analysis

Öz

Induction motors are widely used electrical machines in converting electrical energy into mechanical energy. Common faults ıf induction motors are divided into two groups as electrical and mechanical faults. Electrical faults consist of stator faults and rotor faults. Mechanical faults include bearing failures, axial misalignment and other faults related to the mechanical components of the motor. Bearing failures has significant share in mechanical faults. One of the main causes of bearing failures is  the  misalignment between the motor and the load. In this paper, the effects of the misalignment problems between an induction motor and a load are investigated. A star-flexible coupling was used between the induction motor and the load. The motor was loaded with a self-excited synchronous generator. Motor-load (synchronous generator) misalignments were gradually adjusted by a laser coupling alignment tool. At each alignment level the stator current and vibration signals were recorded. Current and vibration signals were analyzed in the frequency domain. Then entropies of current and vibration signals were calculated. The change in the entropy of current and vibration signals due to misalignment were investigated experimentally. It has been shown that the misalignment problems can be analyzed with the change in entropy of stator current and vibration signals.

Anahtar Kelimeler

• Induction motors,fault analysis,coupling misalignment faults,entrophy analysis

Asenkron Motorlarda Paralel Hizalama Hatalarının Entropi Analizi ile İncelenmesi

Öz

Asenkron motorlar elektrik enerjisinin mekanik enerjiye dönüştürülmesinde yaygın olarak kullanılan elektrik makinalarıdır. Asenkron motorlarda meydana gelen yaygın arızalar elektriksel ve mekaniksel arızalar olarak iki gruba ayrılır. Elektriksel arızalar stator arızaları ve rotor arızalarından oluşmaktadır. Mekaniksel arızalar ise rulman arızaları, eksenel kaçıklık arızaları ve motorun mekanik aksamı ile ilgili olan diğer arızalardan oluşmaktadır. Mekanik arızaların önemli bir kısmını rulman arızaları oluşturmaktadır. Rulman arızalarının ana sebeplerinden bir tanesi kaplin ayarının iyi yapılmaması ve/veya motor-yük arasındaki hizasızlık sonucu meydana gelen mekanik problemledir. Bu makalede bir asenkron motor ile yük arasında meydana gelen hizasızlık probleminin motora etkileri incelendi. Asenkron motor ile yük arasında bir adet yıldız-esnek kaplin kullanıldı. Kendinden uyartımlı bir senkron generatör ile yüklendi. Motor-yük (senkron generatör) arasındaki hizasızlıklar bir lazer kaplin ayar cihazı ile kademeli olarak ayarlandı. Her kademede motor stator akımı ve titreşim sinyalleri kaydedildi. Akım ve titreşim sinyalleri frekans domeninde analiz edildi. Daha sonra entropi değerleri hesaplandı. Hizasızlık problemleriye akım ve titreşim sinyalleri entropi değerinin değişimi deneysel olarak incelendi. Entropi değerindeki değişim ile hizasızlık problemlerinin analiz edilebileceği ispat edildi. 

Anahtar Kelimeler

• Asenkron motor,kaplin hizalama hataları,entropi analizi,arıza analizi

Kaynakça

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