Abolhassani M.,TECO Westinghouse Motor Company
IEEE Transactions on Power Electronics | Year: 2012
A new approach to improve the power quality of high-power medium voltage multilevel drives is presented. A modular transformers strategy in conjunction with modular power electronics cubes is developed. By applying this technology, the input current harmonics decreases to well below the requirement of IEEE 519-1992 while the amount of capacitance installed in the drive is significantly reduced. In addition, by employing modular transformers technology and efficient cooling, power density of the drive is increased by 15%. The input power factor of drive is also improved. This paper details the new approach, analyses, and test results. © 2011 IEEE. Source
Chen W.,TECO Westinghouse Motor Company
Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials | Year: 2015
High potential (Hipot) tests have long been used by many on machine stator windings to assess the integrity of electrical insulation system in question. Most industrial standards limit those recommended test values on completed new machines ready for service or existing machines under service/maintenance conditions. There is only limited information available in the literature regarding tests done on globally VPI'ed windings at pre-VPI green coil and/or green winding stages, and its impact on insulation life. We are aware that a limited few users do specify green coil test requirements, with some of those criteria significantly different than our in-house test standard that has been used for many years with proven effectiveness. This study is to compare these two different test philosophies, to see the advantages and disadvantages between them, and to check whether those different test approaches would affect the ultimate goal: the long term insulation reliability of machines in service. © 2015 IEEE. Source
Heron C.,TECO Westinghouse Motor Company
IEEE Industry Applications Magazine | Year: 2015
Like some of us, the paper industry has been around a long time. Unfortunately, so has a lot of the installed equipment. There have been some upgrades and improvements to machine design over the years, particularly in the areas of insulation and condition monitoring. However, the installed base has not necessarily kept the pace, due in part to the reliability built into older machinery. Today's facilities are under deeper scrutiny as system efficiency, machine reliability, and equipment condition-monitoring improvements are becoming the norm as the industry tries to position itself for the next century. © 2015 IEEE. Source
TECO Westinghouse Motor Company | Date: 2015-12-21
In one embodiment, a power cell chamber for a drive system includes moveable and fixed portions. The moveable portion includes a rectifier stage to rectify an input signal received from a secondary winding of a transformer to provide a rectified signal and an inverter stage having a plurality of switching devices to receive a DC signal and output an AC signal. This moveable portion can be slidably adapted within a cabinet of the drive system. In turn, the fixed portion includes a DC link having at least one capacitor to receive the rectified signal and provide the DC signal to the inverter stage.
TECO Westinghouse Motor Company | Date: 2013-03-15
Cooling assemblies, such as those configured to cool electric machines (e.g., electric motors and generators) and components of electric machines (e.g., rotors and stators).