Over the past five years, the application of variable frequency drives (VFD) in the water treatment processes has seen significant growth. Several factors are driving this change:

• Changes in the water and waste-water treatment processes from batch to continuous
• Advances in the reliability of VFDs
• Escalation of energy costs

This article examines each application of the VFD in the water treatment process, industry trends, and provides insight into the selection of medium voltage drives over low voltage drives for 500-1000 hp applications.

• Medium voltage Insulated Gate Bipolar Transistors (IGBTs)
  
• Oil-filled capacitors
  
• Heat pipe cooling technology
  
• Copper-wound transformer
  
• Lighting arrestors

This article provides some insight into these differentiating features.

Introducing "Drive Time", a new column in the GE Toshiba MV eNews. This column will be published monthly and will feature topics related to drives, motors, and processes that you, our readers, introduce. Have a question on your mind? Contribute to this column by asking questions, sending comments, and participating in the discussion.

To talk to us, click on this article and use the "Letters" link in the left column.

2003 Training Schedule