12.2 Calculating the Required Capacity of Regenerative Resistors
12-7
12
12.2.2 Calculating the Regenerative Energy
This section shows the procedure for calculating the regenerative resistor capacity when acceleration and decel-
eration operation is as shown in the following diagram.
(1) Calculation Procedure
The procedure for calculating the regenerative capacity is as follows:
Note: 1. The “0.2” in the equation for calculating W
K
is the value for when the regenerative resis-
tor’s utilized load ratio is 20%.
2. The units for the various symbols are as follows:
Motor speed
Motor force
F
L
:
Load force
t
D
0
0
Regenerative
force
V
M
: Motor speed
T
Step
Item
Symbol
Equation
1
Calculate the kinetic energy of the linear ser-
vomotor.
E
S
E
S
= MV
M
2
/2
2
Calculate the energy consumed by friction
loss during the deceleration period.
E
L
E
L
= V
M
F
L
t
D
/2
3
Calculate the energy lost from linear servo-
motor winding resistance.
E
M
(Value calculated from “(2) Servo-
motor Winding Resistance Loss”
diagrams)
×
t
D
4
Calculate the SERVOPACK energy that can
be absorbed.
E
C
Calculate from “(3) SERVO-
PACK’s Absorbable Energy” dia-
grams.
5
Calculate the energy consumed by the regen-
erative resistor.
E
K
E
K
= E
S
−
(E
L
+E
M
+E
C
)
6
Calculate the required regenerative resistor
capacity (W).
W
K
W
K
= E
K
/ (0.2
×
T)
Symbol
Units
Meanings
E
S
J
Kinetic energy of linear servomotor
E
L
Energy consumed by friction loss during the deceleration period
E
M
Energy consumed by linear servomotor winding resistance loss
E
C
Energy that can be absorbed by SERVOPACK
E
K
Energy consumed by regenerative resistor
W
K
W
Required capacity of regenerative resistor
M
(=
M
M
+
M
L
)
kg
Load mass including linear servomotor
V
M
m/s
Linear servomotor movement speed
F
L
N
Load force
t
D
sec
Period to decelerate to a stop
T
Repeated operation cycle of linear servomotor
Summary of Contents for SGLFW
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