دانلود رایگان مقاله انگلیسی تست با سنجش تخلیه جزئی درون خطی در موتور تغذیه با اینورتر ولتاژ بالا - نشریه IEEE

Abstract

Partial discharge (PD) testing has long been an important tool for assessing the condition of the high voltage insulation in motor and generator stator windings. In the past several years, many motors have been powered from inverters which facilitate variable speed motor operation. The most common drive used today is the voltage-source, pulse-width-modulation (VS-PWM) type. VS-PWM drives rated up to 13.8 kV are becoming more common in natural gas processing plants, as well as in other petrochemical facilities. Such drives generate high voltage impulses in the kV range with risetimes in the sub-microsecond range. These impulses are a form of severe electrical interference that can make difficult the on-line detection of partial discharge (with magnitudes 1000 times smaller) due to the overlapping frequency content in PD and in the impulses. Thus, PD detection on medium voltage VS-PWM systems has been a challenge in spite of the serious stator winding insulation aging that such drives may cause to these motors. This paper discusses the stator winding failure mechanisms which produce PD, including the insulation problems that VSPWM drives can accelerate. A research project that lasted several years is reviewed. This project culminated in a prototype on-line PD monitoring system suitable for motors fed by VS-PWM drives.

VI. CONCLUSIONS

A method has been demonstrated to measure the stator winding PD during normal operation of medium voltage motors fed from voltage-source, pulse-widthmodulated variable-speed drives. This ability to measure PD on-line is useful to detect not only the normal aging processes in stator windings, but also to detect some aging processes that can be accelerated in such variable speed applications. Further experience will be needed to establish if certain PD patterns are associated with specific insulation deterioration mechanisms associated with such drives.