4-46
4-4 Regenerative Energy Absorption
System Design
4
Vertical Axis
In the output torque graph, acceleration in the positive direction (rising) is shown as positive, and
acceleration in the negative direction (falling) is shown as negative.
The regenerative energy values for each region can be derived from the following equations.
Note Due to the loss of winding resistance, the actual regenerative energy will be approximately
90% of the values derived from these equations.
For Servo Drive models with internal capacitors used for absorbing regenerative energy, the
values for both E
g1
or E
g2
+ E
g3
(unit: J) must be lower than the Servo Drive’s regenerative energy
absorption capacity. (The capacity depends on the model. For details, refer to Servo Drive
Regenerative Energy Absorption Capacity on page 4-47.)
For Servo Drive models with an internal regeneration resistor used for absorbing regenerative
energy, the average amount of regeneration Pr (unit: W) must be calculated, and this value must
be lower than the Servo Drive’s regenerative energy absorption capacity. (The capacity depends
on the model. For details, refer to Servo Drive Regenerative Energy Absorption Capacity on page
4-47.)
The average regeneration power (Pr) is the regeneration power produced in one cycle of
operation [W].
t
1
t
2
t
3
T
E
g1
E
g3
g3
E
g3
T
D2
T
L2
T
D1
E
g2
Servomotor
operation
Servomotor
output torque
Rising
Falling
+N
1
−
N
2
1
1
1
2
π
2
1
t
1
T
N
E
D
g
=
60
*
*
*
*
[J]
2
2
2
2
π
t
2
T
N
E
L
g
=
60
*
*
*
[J]
2
2
2
π
2
1
t
3
T
N
E
D
g3
=
60
*
*
*
*
[J]
N
1
, N
2
: Rotation speed at beginning of deceleration [r/min]
T
D1
, T
D2
: Deceleration torque [N·m]
T
L2
:
Torque when falling [N·m]
t
1
, t
3
:
Deceleration time [s]
t
2
:
Constant-velocity travel time when falling [s]
2
E
g
1
E
g
=
P
r
(
+
) / T [W]
T: Operation cycle [s]
2
E
g
+
