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Topics: VFD Quadrant Operation on Variable frequency drive
Start by
Ajith Nair
09-18-2013 10:57 AM

VFD Quadrant Operation

In VFD What's the meaning of Quadrant Operation(I,II,II,IV) practically , How does it depend on application & What changes do occur in the operational principle in the Circuit & selection criteria ?
09-18-2013 01:12 PM
Top #2
Tony Cutner
09-18-2013 01:12 PM
If you were to plot a speed torque graph, a motor will operate in the top right hand side.
That would be single quadrant.
If the direction was to change, so same torque, but motor reversed, i.e. negative velocity, it would be 2 quadrant drive.
As this is a VFD, the motor can actually dump power into the VFD, which mathematically means the lower 1/2 quadrants are also occupied. Hence you would have a 4 quadrant drive.
Difficult to describe without drawing paper.
09-18-2013 04:04 PM
Top #3
Tony Cutner
09-18-2013 04:04 PM
Here you go, found this on the Internet, with graphics
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