Siemens SIMODRIVE 611 universal Function Manual page 350

6 Description of the Functions
6.1 Operating mode, speed/torque setpoint (P0700 = 1)
Table 6-8 Parameters for limits, continued
No.
1235:8 1st power limit value
... specifies the maximum permissible power referred to the motor power (SRM) or the rated
motor power (ARM – P1130: Rated motor power).
Motor power for SRM [kW] = 1/9549.3 S (P1118 S P1113) S P1400
P1118: Motor standstill (stall) current
P1113: Torque constant
P1400: Rated motor speed
As shown in Fig. 6-7, using the power limiting (constant power), the torque is limited (P = 2p S M
S n; with P = constant ––> M ∼ 1/n).
The minimum of the torque, power and stall torque limits are always effective as limit (refer to
Fig.6-7).
SRM/SLM:
For SRM/SLM, this parameter is automatically pre–assigned using the operator action calcu-
late controller data, whereby the value is obtained from the formula above :
ARM:
The following is especially true for ARM:
If the speed at the start of field weakening is greater than the rated speed, then the ramp–up
times can already be shorted and the power yield increased if only the power limit is increased
(with the same current limit). As the current limit (P1238) can also limit the maximum torque
which can be specified, if the output limit (power limit) is increased further, more torque can only
be obtained if the current limit is also increased.
Important:
If the motor is overloaded for a longer period of time, this can result in an impermissible temper-
ature rise (the drive is shutdown as a result of a motor overtemperature condition); the motor
can also be destroyed.
Corresponding parameters are: P1104, P1145 and P1233 to P1238
1233:8 Regenerative limiting
... specifies the regenerative limiting.
The setting refers to the parameter value in P1230.
1237 Maximum regenerative power
... allows the regenerative power to be limited for the input/regenerative feedback module.
An appropriately lower value should be entered here, especially when using an uncontrolled NE
module.
6-350
Parameters
Description
P1235 = (P1104/P1118) S 100 %
The standard default is 100 %.
Note
Torque/power reduction
It is possible to continuously reduce the torque/power by reducing the
effective torque limit.
S
for terminals:
via analog input 2 (terminal 24.x/20, refer to Chapter 6.6.4).
S
for PROFIBUS–DP:
using the "MomRed" control word (refer to Chapter 5.6.6).
SIMODRIVE 611 universal Description of Functions (FBU) – 04.05 Edition
Min. Standard Max.
5.0 100.0 900.0
5.0 100.0 100.0
0.1 100.0 500.0
E Siemens AG 2005 All Rights Reserved
01.99
Units Effec-
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% Imme-
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kW Imme-
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