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Sigma II User's Manual
n
By Calculating the Regenerative Energy
This section shows the procedure for calculating the regenerative resistor capacity
when acceleration and deceleration operation is as shown in the following diagram.
Rotation speed
Motor torque
Calculation Procedure
The procedure for calculating the capacity is as follows:
Step
Procedure
Find the rotational energy of the
1
servo system (E
S
Find the energy consumed by
load system loss (E
2
deceleration period (t
Calculate the energy lost (E
3
from servomotor winding resis-
tance.
Calculate the servoamp energy
4
(E
) that can be absorbed.
C
Find the energy consumed by
5
the regenerative resistor (E
Calculate the required regener-
6
ative resistor capacity (W
Note: 1. The "0.2" in the equation for calculating W
lized load ratio is 20%.
N
: Motor rotation speed
M
0
T
: Load torque
L
0
E
=
S
).
J
=
L
N
=
M
τ
=
L
E
=
L
) during the
L
N
=
M
).
D
t
=
D
)
M
t
=
D
E
=
M
E
=
C
E
=
K
).
K
W
=
K
E
=
K
).
K
T
=
Chapter 5: Parameter Settings and Functions
tD
Regenerative
torque
T
Units
[in. (mm)]
[Joules] = [J]=
2
2
2
[ oz·in·s
(kg·m
·s
)]
J
= J
M
rpm
oz·in (N·m)
Joules = J
rpm
s
s
Joules = J
Joules = J
E
=E
=E
= E
=
S
L
M
C
Joules = J
W
Joules = J
s
is the value for when the regenerative resistor's uti-
K
5-86
Equation
) × Ν
(
J
+ J
L
M
E
=
S
182
Where: N
= Motor speed
M
J
= Load Inertia
L
J
= Motor Inertia
M
(
π
Ν
× τ
× t
E
=
Μ
L
L
60
τ
Where:
= Motor torque
L
E
= Value from the "Servomotor
M
Winding Resistance Loss" graph
below.
E
= Value from the "Absorbable
C
Servo Amplifier Energy" graph
below.
(
)
E
= E
— E
+E
+ E
K
S
L
M
C
E
K
W
=
K
0.2 × T
Where: T = Time
2
Μ
)
D
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