| Abstract [eng] |
The purpose of this thesis is analysis of air gap of induction motor using control windings and determine the accuracy of the method. Stages of research: To review the existing induction motor diagnostic methods.To make research induction motor using control windings and vibro-sensor. Compare accuracy between control windings and vibro-sensor. Set implemented method pros and cons. Make recommendations. For experimental study is used: three phase induction motor, ball bearings with outer ring defect, ball bearings with ball and separator defect. Clark‘e and Park vector transformations. Using control windings diagnosis for ball bearing defects it‘s quite difficult to determine bearing failures, because the air gap magnetic flux varies a little and induced voltage of control windings changing only 0.005 mV. And it is determined that bearing vibration monitoring using vibro-sensors is more reliable to use. Control windings main advantage is determining electrical faults of induction motor, even the motor have no load, rotor or stator faults immediately brings change in the air gap magnetic flux and control windings induced voltage is asymmetrical. After using Clark‘e and Park transformation on control windings induced voltage, it is easy to determine fault of induction motor. Control windings in stator can be laid only in the production at the factory or during scheduled maintenance work because of the need to dismantle induction motor. |
