Estimation of lifespan of motors considering multiple stresses

• Main Author: Yu, Kun.
• Other Authors: Tan Yoke Lin
• Format: Theses and Dissertations
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electric power
• Online Access: http://hdl.handle.net/10356/18873
• Institution: Nanyang Technological University

Categorization of failures in large rotating machines shows that stator insulation problems are together with bearings, major causes of downtime. With the increasing demand for reliable power systems with minimum operational cost, detection of the ‘health’ of HV insulation is attracting more and more attention. Traditionally, a common approach is to measure the Partial Discharge activity, which can indicate the stator winding insulation problems well before failure would occur. Much work has done over the years to model insulation degradation under electric stress. However, efforts aimed at Partial Discharge in the existing models appear to be scanty. As only static samples were used in the previous laboratory studies on the mechanism of PD aging, the effect of mechanical vibration on PD behavior has not been known clearly. In the present work, the author describes the aging model for partial discharge, and the PD patterns at different frequencies and lead phase of mechanical vibrations will be discussed. Then the temperature about Singapore is discussed, and then some simulation is done on how the field in the gap is influenced by the partial discharge. Besides, ho the lifespan of the motor is determined by the gap length is also discussed.