Mitsubishi Electric MELSERVO-J2-Super Series Instruction Manual page 301

15. OPTIONS AND AUXILIARY EQUIPMENT
(2) Selection of the regenerative brake option
(a) Simple selection method
In horizontal motion applications, select the regenerative brake option as described below:
When the servo motor is run without load in the regenerative mode from the running speed to a
stop, the permissible duty is as indicated in Section 5.1 of the separately available Servo Motor
Instruction Manual.
For the servo motor with a load, the permissible duty changes according to the inertia moment of
the load and can be calculated by the following formula:
Permissible duty for servo motor with no load (value indication Section 5.1 in Servo Motor Instruction Manual)
Permissible
duty
where m
From the permissible duty, find whether the regenerative brake option is required or not.
Permissible duty number of positioning times [times/min]
Select the regenerative brake option out of the combinations in (1) in this section.
(b) To make selection according to regenerative energy
Use the following method when regeneration occurs continuously in vertical motion applications or
when it is desired to make an in-depth selection of the regenerative brake option:
a. Regenerative energy calculation
Use the following table to calculate the regenerative energy.
Regenerative power
1)
2)
3)
4), 8)
5)
6)
7)
From the calculation results in 1) to 8), find the absolute value (Es) of the sum total of negative
energies.
ratedspeed
running speed
load inertia moment/servo motor inertia moment
M
Friction
torque
T
F
T
U
Formulas for calculating torque and energy in operation
Torque applied to servo motor [N m]
(J J )
N
L M
0
T
1
4
9.55 10
T T T
2 U F
(J J )
N
L M
0
T
3
4
9.55 10
T T
4 U
(J J )
N
L M
0
T
5
4
9.55 10
T T T
6 U F
(J J )
N
L M
0
T
7
4
9.55 10
(m 1)
2
[times/min]
tf(1 cycle)
N0
Up
t1 t2
T T
psd1
psa1
1)
( )
(Driving)
2)
4)
3)
(Regenerative)
( )
1
T T
E
U F 1
T
psa1
E
2
1
T T E
U F 3
T
psd1
E 0 (N0 regeneration)
4
1
T T E
U F
5
T
psa2
E
6
1
T T E
U F 7
T
psd2
15 - 2
Time
Down
t3 t4
T T
psa2 psd2
8)
5)
6)
7)
Energy [J]
0.1047
N T T
0 1 psa1
2
0.1047 N T t
0 2 1
0.1047
N T T
0 3 psd1
2
0.1047
N T T
0 5 psa2
2
0.1047 N T t
0 6 3
0.1047
N T T
0 7 psd2
2