6
05.01
6.7 DC link options
6-197
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
6.7.4
Engineering information is applicable for UI 5 kW, 10 kW, 28 kW
and PR module
Sizing the load duty cycles with pulsed resistors
E [Ws]
Regenerative feedback energy when braking a motor from n
2
to n
1
T [s]
Period of the braking load duty cycle
A [s]
Load duration
J [kgm
2
]
Total moment of inertia (including J motor)
M [Nm]
Braking torque
n [RPM]
Speed
Pn [W]
Continuous power rating of the pulsed resistor
P
max
[W]
Peak power of the pulsed resistor
E
max
[Ws]
Energy of the pulsed resistor for a single braking operation
t (s)
P (kW)
P
max
P
n
0 kW
0 kW
A
A
T
Fig. 6-26
Load duty cycle for internal and external pulsed resistors
Table 6-26
Examples
Values
PR 0.2/10 kW
PR 0.3/25 kW
PR 1.5/25 kW
E
max
Pn
P
max
13500 Ws
1)
200 W
10000 W
7500 Ws
300 W
25000 W
180000Ws
1500 W
25000 W
Example
A =
T =
0.2 s
10 s
0.12 s
10 s
0.6 s
10 s
A =
T =
1.35 s
67.5 s
0.3 s
25 s
7.2 s
120 s
1) As a result of the mechanical dimensions, the resistor can absorb a relatively high level of energy.
The following conditions must be fulfilled:
1. P
max
w
M
S
2
S
π
S
n/60
2. E
max
w
E; E=J
S
[(2
S
π
S
n
2
/60)
2
–(2
S
π
S
n
1
/60)
2
]/2
3. P
n
w
E/T
J
Load duty cycles
for braking
operations
6 Infeed Modules
02.07
