Four quadrant operation refers to a machine that can operate in four operating modes: forward motoring, forward braking, reverse motoring, and reverse braking. This is achieved by controlling both the direction of torque and the direction of speed. The document discusses four quadrant operation of hoist loads specifically, explaining that a hoist requires operation in all four quadrants to lift and lower loads both forwards and backwards. It provides examples of operation in each quadrant, with the first quadrant representing lifting the load forwards and the fourth quadrant lowering the load backwards through reversing the speed direction.

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MULTI QUADRANT OPERATION
OF HOIST LOAD
Name : Ranjan Ghosh
Dept : Electrical Engineering
Roll No : 11901621021
Year : 4th

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.
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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 USGIN
Hoist load

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1ST QUADRANT (FORWARD MOTORING):
j

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 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.

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 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.

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3RD QUADRANT (REVERSE MOTORING):
 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.
 The speed direction is
unchanged while the direction
of the torque is reversed.

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3RD QUADRANT (REVERSE
MOTORING):
 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.
 The speed direction is
unchanged while the direction of
the torque is reversed.

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4TH QUADRANT (REVERSE
BRAKING):
 The torques remains unchanged
as compared
quadrant. The
to the first
speed, however,
changes the direction.

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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Function Quadrant Speed Torque
Power
Output
Forward
Motoring
I + + +
Forward
Braking
II + - -
Reverse
Motoring
III - - +
Reverse
Braking
IV - + -
MULTI QUADRANT OPERATION OF DRIVE

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A OPERATION APPLICATION OF FOUR QUADRANT
 Compressor, pump and fan type load requires operation
in the I quadrant only. As their operation is
one quadrant drive
they are called
drives require operation in both
unidirectiona
l, systems.
 Transportatio
n 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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