+α +α
−α −α
+slip
+T
-slip
-T
−ω +ω
-V
Reverse
+V
Forward
-P Braking
+P Motoring Braking -P
Motoring +P
IIV
IIIII
Figure 7-1 Four Quadrant Operation of a Motor
The diagram shows the relationship between the polarities of the signals in the ordinances of the
two axes.
This is governed by the following equations:
α = T/J ω = ∫αdt
where:
α = acceleration T = torque
J = inertia (an unsigned magnitude) ω = rotational speed
Starting at rest, if a positive torque is applied to the motor, the acceleration is positive and the
resultant speed increases in the forward direction. Once the motor is rotating in the forward
direction, if the applied torque becomes negative, the quadrant will switch over into quadrant
II, showing that a negative torque produces negative acceleration i.e., deceleration, which will
stop the motor.
If, however, the same torque is applied continuously, the speed of the motor will decrease to
zero and begin to accelerate in the opposite direction producing a negative rotational speed (ω)
in what is now quadrant III. Now if a positive torque is applied, the motor enters quadrant IV and
begins to decelerate as the rotational speed is negative. Once the speed decreases to zero, it
Operating the Control
7.2 Frame of Reference
NXGPro+ Control Manual
Operating Manual, A5E50491925A 179
To Next Page
Loading...
