Specifications
6– 3
6
6. OPTIONS AND AUXILIARY EQUIPMENT
2) To make selection according to regenerative energy
Use the following method when regeneration occurs continuously in vertical motion applica-
tions 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.
b. 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 am-
plifier in the regenerative mode.
Inverse efficiency (η) : Efficiency including some efficiencies of the servo motor and servo
amplifier when rated (regenerative) torque is generated at rated speed.
Since the efficiency varies with the speed and generated torque, allow
for about 10%.
Capacitor charging (Ec) : Energy charged into the electrolytic capacitor in the servo amplifier.
Subtract the capacitor charging from the result of multiplying the sum total of regenerative ener-
gies by the inverse efficiency to calculate the energy consumed by the regenerative brake option.
E
R [J] = η • Es–Ec
Calculate the power consumption of the regenerative brake option on the basis of single-cycle
operation period tf [s] to select the necessary regenerative brake option.
PR [W] = ER/tf ...................................................................................... (6-1)
Servo Amplifier
Inverse Efficiency[%]
55
70
85
85
80
80
85
85
Capacitor Charging[J]
9
9
11
11
18
18
40
40
MR–J2–10A(1)
MR–J2–20A(1)
MR–J2–40A(1)
MR–J2–60A
MR–J2–70A
MR–J2–100A
MR–J2–200A
MR–J2–350A
1)
2)
3)
4), 8)
5)
6)
7)
Torque applied to servo motor [N • m]
Sum total of regenerative energies
Sum total of negative energies in 1) to 8)
Energy [J]
Formulas for Calculating Torque and Energy in Operation
1
TPsa1
(JL + JM)•No
9.55 x 10
4
T1 = •
0.1047
2
E1
=
T2 = TU + TF
E2
= 0.1047•No•T2•t1
E6
= 0.1047•No•T6•t3
E4 0 (
Not regenerative)
•No•T1•TPsa1
0.1047
2
E3
= •No•T3
•TPsd1
0.1047
2
E5
= •No•T5•TPsa2
0.1047
2
E7
= •No•T7•TPsd2
+ TU + TF
1
TPsd1
(JL + JM)•No
9.55 x 10
4
T3 = •
T4 = TU
+ TU + TF
1
TPsa2
(JL + JM)•No
9.55 x 10
4
T5 = •
T6 = TU + TF
- TU + TF
1
TPsd2
(JL + JM)•No
9.55 x 10
4
T7 = • - TU + TF
Regenerative
Power
Servo motor speed
Generated torque
Time
Up
No
tf(1 cycle)
Down
( + )
( - )
e
u
wr
y
i
t
q
(Driving)
(Regenerative)
T
psd2
t
2
t
3
t
4
t
1
T
psa2
T
psd1
T
psa1
M
Friction
torque
Unbalance torque
T
F
T
U