Siemens MICROMASTER 420 - Manual (Page 145)

Issue 07/04 3 Functions
MICROMASTER 420 Operating Instructions
6SE6400-5AA00-0BP0 145
3.21.1.1 Voltage boost
Parameter range: P1310, P1311, P1312
r0056 bit 05
Warnings -
Faults -
Function chart number:
FP6100
For low output frequencies, the V/f characteristics only output a low output voltage.
Even at low frequencies, the ohmic resistances of the stator winding play a role,
which are neglected when determining the motor flux in Section 3.21.1. This means
that the output voltage can be too low in order to
implement the magnetization of an induction motor,
to hold the load
to voltage drops (ohmic losses in the winding resistances) in the system or
to provide a breakaway / accelerating / braking torque.
The output voltage can be increased (boosted) in MICROMASTER using the
following parameters (refer to Table 3-28):
Table 3-28 Voltage boost
Parameter Voltage boost Explanation
P1310 Constant
voltage boost
The voltage boost is effective over the complete
frequency range whereby the value continually
decreases at high frequencies.
f
Linear V/f
OFF
ON
t
t
 f 
P1310 active
t 0
1
Validity range
Vmax
Vn
(P0304)
V
ConBoost,100
0 fn
(P0310)
f max
(P1082)
V
f
Boost,end
(P1316)
Boost
Ou
tpu
t v
olt
ag
e
actual V
No
rm
al
V/
f
(P
13
00
=
0
)
V
ConBoost,50
Boost voltage
\\erlf305a\Graphics_PLI\Images\p1310_linear_MM420.vsd
P1311 Voltage boost when
accelerating- / braking The voltage boost is only effective when accelerating
or braking.