6
05.01
6.7 DC link options
6-194
© Siemens AG 2008 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 05/2008 Edition
6.7.5 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. 6-23 Load duty cycle for internal and external pulsed resistors
Table 6-22 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
M S 2 S π S n/60
2. E
max
E; E=J S [(2 S π S n
2
/60)
2
–(2 S π S n
1
/60)
2
]/2
3. P
n
E/T
J
Load duty cycles
for braking
operations
6 Infeed Modules 11.0502.07
To Next Page
Loading...
