158
To let users easily calculate the power of external brake resistor, the calculations are described below.
(a) Without external load
If the motor is repeated running forward and reverse, the braking regenerative energy would return to
the aluminum capacitors of servo drive. When the P-N voltage exceeds a particular value, the brake
IGBT switch is turn on and the brake resistor would dissipate the regenerative energy. The following
statement and table provide the calculation of regenerative power.
The Es and Ec of various drive capacity are listed below.
Drive (W)
Rotor inertia, J
(x10
-4
kg
‧
m
2
)
Motor type
(*1)Regenerative
Energy
Es
(joule)
(*2)Regenerative
Energy
Ec
(joule)
Max. motor
speed (rpm)
Lo
w
ine
rt
ia
100
0.056
SME-M10020
○□□□
0.28
16.18
3000
200
0.137
SME-M15020
○□□□
0.68
16.18
3000
400
0.270
SME-M20020
○□□□
1.33
19.78
3000
750
1.230
SME-M30020
○□□□
6.07
33.56
3000
1K
6.070
SME-M10020
○□□□
13.31
33.56
2000
1.5K
8.800
SME-M15020
○□□□
19.30
81.50
2000
2K
11.50
SME-M20020
○□□□
25.22
81.50
2000
3K
17.00
SME-M30020
○□□□
37.29
81.50
2000
Me
d
ium
i
n
erti
a
1K
10.60
SME-M10020
○□□□
23.25
33.56
2000
1.5K
15.60
SME-M15020
○□□□
34.21
81.50
2000
2K
32.40
SME-M20020
○□□□
71.06
81.50
2000
3K
62.20
SME-M30020
○□□□
136.42
81.50
2000
Note1: Es is the regenerated energy of a motor without loading that runs a rated speed then stops.
Note2:
Ec is the motor deceleration energy that charges into the DC capacitors.
The capacity of brake resistor is calculated as follows:
BR
S
C
P
2
N+1
E
E
T
(
) /
Where:
BR
P
: Power of brake resistor
N : The ratio of load inertia to motor shaft
T : Duty cycle
(Defined by users)
If the ratio of load inertia to motor shaft is N, deceleration from the rated speed to stop; the
regenerative energy is (N +1) × Es. The brake resistor consumption is (N +1)× Es - Ec joules. Assuming
the duty cycle is T second, then the recommend power of brake resistor is 2 × ((N +1) × Es-Ec) / T. The
calculation procedure is as follows. J is the motor inertia. (unit: kg
‧
m2)
Summary of Contents for SDE Series
Page 13: ...5 1 6 Function block diagram ...
Page 26: ...18 3 3 3 CN1 pin name list ...
Page 223: ...215 SME L040 SME L075 SME L100 SME L150 ...
Page 224: ...216 SME L200 SME L300 SME M100 SME M150 Continuous running range ...
Page 227: ...219 ...
Page 231: ...223 4 Wiring example with peripheral equipment CN2 Encoder socket ...
Page 242: ...234 12 4 Version information Version V1 01 Issue date Aug 2017 Proofreader Yaochou Shu ...