Minarik NRGD-4Q Series, User Manual

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Regenerative Drives
Non-regenerative, variable speed DC drives control current and
speed to a motor in one direction only. The direction of current
flow is in the same direction as the motor rotation. This is
commonly described as Single Quadrant operation. (Quadrants 1
or 3 depending on your direction of rotation-see Figure 1).
Non-regenerative drives cannot oppose an overhauling load with
reverse torque, nor decelerate a load faster than coasting to a
lower speed. Dynamic braking with an external brake resistor
can be added to accomplish these things; however, it would
require the use of an external switch.
Regenerative drives, however, can operate in all four quadrants of
operation. They are able to control motor speed and current in
both directions simultaneously. Thus, regenerative drives can
reverse a motor, oppose an overhauling load and decelerate a load
faster than it would take to coast to a lower speed–all without any
external contactors or switches.
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