Siemens simovert masterdrives, Справочник

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09.2008 Functions
Siemens AG 6SE7087-6QX70 (Version AK)
SIMOVERT MASTERDRIVES Compendium Motion Control
7-69
3. Set the characteristic to meet requirement "Maximum torque in field
weakening range remains constant":
The output voltage (r003) at the field weakening activation speed
under no load conditions must be measured. The output voltage at
the end point of the desired field weakening range must then be
calculated according to the following formula from the maximum
converter output voltage (depends on converter supply voltage) and
the calculated output voltage at the field weakening activation
speed:
( )
speed activation weakening field nd a speed eakening w
field final between Ratio : range weakening Field
n
n
k
speed activation weakening field at voltage Output U
range weakening field of end at oltage v Output U
) V 540 UDCL when ( V 350 U
where
k U k 1 U U
Act
End
f
nAct Out Conv
nEnd Out Conv
max Conv
2
f
2
nAct Out Conv
2
f
2
max Conv nEnd Out Conv
=
=
=
= =
⋅ + − ⋅ =
The formula is based on the simplified principle that the voltage drop
across the winding resistance of the motor is negligible in the field
weakening range. This applies to series 1FT6 and 1FK7 servo
motors.
The output voltage calculated by this formula must then be set at the
end speed of the field weakening range at no load via the short-
circuit current. The current setting must be increased in relation to
the automatically calculated value, as the automatic arameterization
run defines the short-circuit current for operation at constant
maximum output.
1FT6086 - 8AF71
Field
weakening
activation point
0
10
20
30
40
50
60
70
80
90
100
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Speed [min-1]
Torque [Nm]
e.g. 1FT6086-8AF71, 27.5 Nm at 2900 rev/min to 4500 rev/min,
U
(no load 2900)
= 296 V, U
(no load 4500)
= 174 V I
k
(P105) = 60 A