Mitsubishi Electric MELSERVO-J5 User Manual page 181

Regenerative Torque T applied to servo motor [N•m]
power
(1)
(J /η + J
L
T =
1
9.55 • 10
(2) T = T
2 L
(3)
-(J • η + J
L
T =
3
9.55 • 10
(4), (8) T , T = 0
4 8
(5)
(J /η + J
L
T =
5
9.55 • 10
(6) T = T
6 L
(7)
-(J • η + J
L
T =
7
9.55 • 10
*1 Load torque converted into equivalent value on servo motor shaft TL can be calculated with the following formula.
T = {(F + (μ × W × g)) × ΔS} / (2000 × π × η)
L C L
*2 Load moment of inertia converted into equivalent value on servo motor shaft JL can be calculated with the following formula.
J = J + J + J
L L1 L2 L3
J is the load moment of inertia of the moving part, J
L1
inertia of the coupling. J and J
L1
2
J = W × (ΔS / (20 × π))
L1 L
J = {(π × 0.0078 × (L / 10)) / 32} × (D
L2 B
From the calculation results in (1) to (8), find the absolute value (Es) of the sum total of negative energies.
■Losses of servo motor and servo amplifier in regenerative mode
The following table lists the efficiencies and other data of the servo motor and servo amplifier in the regenerative mode.
Servo amplifier
MR-J5-10_
MR-J5-20_
MR-J5-40_
MR-J5-60_
MR-J5-70_
MR-J5-100_
MR-J5-200_
MR-J5-350_
MR-J5-500_
MR-J5-700_
MR-J5-60_4_
MR-J5-100_4_
MR-J5-200_4_
MR-J5-350_4_
Inverse efficiency (η ): Efficiency including some efficiencies of the servo motor and servo amplifier when rated (regenerative)
m
torque is generated at rated speed. Efficiency varies with the servo motor speed and generated torque. Because the
characteristics of the electrolytic capacitor change with time, allow inverse efficiency of approximately 10 % higher than those
shown above.
Capacitor charging (Ec): Energy charged into the electrolytic capacitor in the servo amplifier
Multiply the sum total of regenerative energies by the inverse efficiency, and subtract the capacitor charging from that result to
calculate the energy consumed by the regenerative option.
ER [J] = η • E - E
m s c
Select a regenerative option that meets the requirements of the system by calculating the power consumption of the
regenerative option based on a one-cycle operation period tf [s].
PR [W] = ER/tf
*1*2
) • N 1
M
•
+ T
L
4
t
psa1
) • N 1
M
• + T
L
4
t
psd1
) • N 1
M
• + T
L
4
t
psa2
) • N 1
M
• + T
L
4
t
psd2
is the load moment of inertia of the ball screw, and J
L2
can be calculated with the following formulas.
L2
4
/ 10)
B
Inverse efficiency [%]
70
85
90
90
90
90
90
90
90
90
85
85
85
85
Energy E [J]
0.1047
• N • T • t
E =
1 psa1
1
2
E = 0.1047 • N • T • t
2 2 1
0.1047
E = • N • T • t
3 3 psd1
2
E , E = 0 (No regeneration)
4 8
0.1047
• N • T • t
E =
5 5 psa2
2
E = 0.1047 • N • T • t
6 6 3
0.1047
E = • N • T • t
7 7 psd2
2
Capacitor charging [J]
9
9
11
11
18
18
36
40
45
70
9
12
25
35
6 OPTIONS AND PERIPHERAL EQUIPMENT
6.2 Regenerative option
is the load moment of
L3
179
6