Siemens SIMOTICS T-1FW6 Configuration Manual

Configuration
5.2 Configuring workflow
1FW6 Built-in torque motors
Configuration Manual, 07/2017, 6SN1197-0AE00-0BP9
109
5.2.10
Calculation of the required infeed
Dimensioning the Active Infeed
Use the drive's power balance to dimension the Active Infeed.
The first important quantity to know is the mechanical power P
mech
to be produced on the
motor shaft. Based on this shaft output, the electrical active power P
Line
to be drawn from the
supply system can be determined by adding the power loss of the motor P
V Mot
, the power
loss of the Motor Module P
V MoMo
and the power loss of the Active Infeed P
V AI
to the
mechanical power P
mech
:
P
Line
= P
mech
+ P
V Mot
+ P
V MoMo
+ P
V AI
.
The active power to be drawn from the power system depends on the line voltage U
Line
, the
line current I
Line
and the line-side power factor cosφ
Line
as defined by the relation
P
Line
= √3 • U
Line
• I
Line
• cosφ
Line
.
This is used to calculate the required line current I
Line
of the Active Infeed as follows:
I
Line
= P
Line
/ (√3 • U
Line
• cosφ
Line
).
If the Active Infeed is operated according to the factory setting, i.e. with a line-side power
factor of cosφ
Line
= 1, so that it draws only pure active power from the supply, then the
formula can be simplified to
I
Line
= P
Line
/ (√3 • U
Line
).
The Active Infeed must now be selected such that the permissible line current of the Active
Infeed is higher or equal to the required value I
Line
.
5.2.11
Voltage Protection Module
The VPM Voltage Protection Module is used for motors with an EMF of Û > 820 V to 2000 V
(U
eff
> 570 V to 1400 V), in order to limit the DC voltage at the drive system in the case of a
fault.
The VPM identifies an excessively high DC voltage (U
DC
> 820 V), short-circuits the three
motor feeder cables and therefore brakes the motor. The energy remaining in the motor is
converted into heat as a result of the short-circuit in the VPM and in the motor winding.
The maximum speed n
MAX,INV
is specified in the data sheets, where no Voltage Protection
Module VPM is required.
You can dimension the VPM using the following formula to calculate the motor short-circuit
current I
K
:
I
K
= k
T
/ (3 • p • L
STR
)
The explanations of the codes used in the formula can be found in Chapter "Technical data
and characteristics".

Siemens SIMOTICS T-1FW6 Specifications

General

Brand	Siemens
Model	SIMOTICS T-1FW6
Category	Engine
Language	English