multi quadrant Dynamics of Electric Drive

1. 1
Multi Quadrant operation
of Hoist load
Dr. A. Ravi
Professor/EEE
FRANCIS XAVIER ENGINEERING COLLEGE
TIRUNELVELI- India

2.  Four Quadrant Operation of any drives or DC Motor
means that the machine operates in four quadrants.
 They are
 Forward Braking,
 Forward motoring
 Reverse motoring
 Reverse braking.
2
Four Quadrant Operation

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• Direction of positive
(forward) speed is arbitrary
chosen
• Direction of positive torque will
produce positive (forward) speed
Quadrant 1
Forward motoring
Quadrant 2
Forward braking
Quadrant 3
Reverse motoring
Quadrant 4
Reverse braking
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Multi Quadrant operation of Motor using
Hoist load

5. 5
 The electrical
machine in this case is
operating as a motor.
The flow of power is
from the machine to
the load.
1st Quadrant (Forward Motoring):
The torque and speed of the motor
are in the same direction. Of
course, the load torque is opposite
to the machine torque.

6. 6
 The machine then receives
mechanical energy,
converting it in to electrical
energy and returning it back
to the electric source. The
electric machine is thus
acting as a Generator.
2nd Quadrant (Forward Braking):
 The speed direction is
unchanged while the direction of
the torque is reversed.

7. 7
 The machine then receives
mechanical energy,
converting it in to electrical
energy and returning it back
to the electric source. The
electric machine is thus
acting as a Generator.
2nd Quadrant (Forward Braking):
 The speed direction is
unchanged while the direction of
the torque is reversed.

8. 8
 Since the torque and speed of
the machine are in the same
direction, the power flow is
from the machine to the load.
The machine is therefore acting
as a motor rotating in the
reverse direction to the speed of
the first quadrant.
3rd Quadrant (Reverse Motoring):
 The speed direction is
unchanged while the direction of
the torque is reversed.

9. 9
 Since the torque and speed of
the machine are in the same
direction, the power flow is
from the machine to the load.
The machine is therefore acting
as a motor rotating in the
reverse direction to the speed of
the first quadrant.
3rd Quadrant (Reverse Motoring):
 The speed direction is
unchanged while the direction of
the torque is reversed.

10. 10
 From the load perspective, the
load torque and the speed are in
the same direction. Hence the
power flow is from the load to the
machine.
4th Quadrant (Reverse Braking):
 The torques remains unchanged
as compared to the first
quadrant. The speed, however,
changes the direction.
 The machine is in this case acting as generator delivering the electric power to
the source.

11. 4th Quadrant (Reverse Braking):
 The first and fourth quadrant of operation can be explained with the
elevator. When the elevator is going upward or downward, the
direction of the load torque remains unchanged but the direction of
the speed only reversed.
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12. 12
Function Quadrant Speed Torque
Power
Output
Forward
Motoring
I
+ + +
Forward
Braking
II
+ - -
Reverse
Motoring
III
- - +
Reverse
Braking
IV
- + -
Multi quadrant operation of drive

13. 13
Applications of Four Quadrant Operation
 Compressor, pump and fan type load requires operation
in the I quadrant only. As their operation is
unidirectional, they are called one quadrant drive
systems.
 Transportation drives require operation in both
directions.
 If regeneration is necessary, application in all four
quadrants may be required. If not, then the operation is
restricted to quadrants I and III, and thus dynamic
braking or mechanical braking may be required.
 In hoist drives, a four-quadrant operation is needed.

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