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Options and auxiliary equipment – MITSUBISHI ELECTRIC MR-J2S- CL User Manual

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14 - 2

14. OPTIONS AND AUXILIARY EQUIPMENT

(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.

M

Friction
torque

Unbal

a

n

ce t

o

rque

T

F

T

U

S

e

rv

o m

o

to

r s

p

e

e

d

G

e

n

e

ra

ted t

o

rque

Time

Up

N0

tf(1 cycle)

Down

( )

( )

(Driving)

(Regenerative)

T

psd2

t2

t3

t4

t1

T

psa2

T

psd1

T

psa1

1)

2)

3)

4)

5)

6)

7)

8)

Formulas for calculating torque and energy in operation

Regenerative power

Torque applied to servo motor [N m]

Energy [J]

1)

T

1

1

T

psa1

T

U

T

F

(J

L

J

M

)

9.55 10

4

N

0

E

1

2

0.1047

N

0

T

1

T

psa1

2)

T

2

T

U

T

F

E

2

0.1047 N

0

T

2

t

1

3)

T

3

1

T

psd1

T

U

T

F

(J

L

J

M

)

9.55 10

4

N

0

E

3

2

0.1047

N

0

T

3

T

psd1

4), 8)

T

4

T

U

E

4

0 (N0 regeneration)

5)

T

5

1

T

psa2

T

U

T

F

(J

L

J

M

)

9.55 10

4

N

0

E

5

2

0.1047

N

0

T

5

T

psa2

6)

T

6

T

U

T

F

E

6

0.1047 N

0

T

6

t

3

7)

T

7

1

T

psd2

T

U

T

F

(J

L

J

M

)

9.55 10

4

N

0

E

7

2

0.1047

N

0

T

7

T

psd2

From the calculation results in 1) to 8), find the absolute value (Es) of the sum total of negative
energies.

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 amplifier in
the regenerative mode.

Servo amplifier

Inverse efficiency[%]

Capacitor charging[J]

MR-J2S-10CL (1)

55

9

MR-J2S-20CL (1)

70

9

MR-J2S-40CL (1)

85

11

MR-J2S-60CL

85

11

MR-J2S-70CL

80

18

MR-J2S-100CL

80

18

MR-J2S-200CL

85

40

MR-J2S-350CL

85

40

MR-J2S-500CL

90

45

MR-J2S-700CL

90

70

Inverse efficiency ( )

: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.