1
MMRG Series
Most
non-regenerative,
variable speed, DC drives
control current flow to a
motor in one direction.
The direction of current
flow is the same direction
as the motor rotation.
Non-regenerative drives
operate in Quadrant I,
and also in Quadrant III if
the drive is reversible (see
Figure 1). Motors must stop
before reversing direction.
Unless dynamic braking
is used, non regenerative
drives cannot decelerate a
load faster than coasting to a
lower speed.
Regenerative drives operate
in two additional quadrants:
Quadrant II and Quadrant
IV. In these quadrants,
motor torque is in the
opposite direction of motor rotation.
This allows regenerative drives to reverse a motor without contractors
or switches, to control an overhauling load, and to decelerate a load
faster than it would to coast to a lower speed.
Section 1. Regenerative Drives
ARROWS IN OPPOSITE DIRECTION = REGENERATIVE ACTION
NOTE: ARROWS IN SAME DIRECTION = MOTOR ACTION
MOTOR
TORQUE
ROTATION
MOTOR
Quadrant III
Quadrant II
Quadrant IV
Quadrant I
Figure 1. Four Quadrant Operation
