Siemens MICROMASTER 420 - Manual (Page 144)

3 Functions Issue 07/04
MICROMASTER 420 Operating Instructions
144 6SE6400-5AA00-0BP0
f
U, M, P, Φ
Voltage control range Field control range
Rated motor
operating point M
n
, Φ
n
f
n
f
max
M, Φ
U, P
U, P
Fig. 3-61 Operating ranges and characteristics of an induction motor when fed from a
drive inverter
There are several versions of the V/f characteristic as shown in Table 3-27.
Table 3-27 V/f characteristic (parameter P1300)
Parameter
value
Significance Use / property
0 Linear
character-
istic
Standard case
V
n
0 f
n
V
f
P1300 = 0
1 FCC Characteristic which compensates the voltage losses of the stator
resistance for static (steady-state) or dynamic loads (flux current control
FCC). This is especially used for small motors which have a relatively high
stator resistance. Refer to Section 3.21.1.2.
2 Square-law
character-
istic
This is a characteristic which
takes into consideration the
torque characteristic of the driven
load (e.g. fan / pump)
a) Square-law characteristic
(f 2 characteristic)
b) Energy saving as the lower
voltage also results in lower
currents and losses.
V
n
0 f
n
V
f
P1300 = 2
3 Programm-
able
character-
istic
Characteristic which takes into
consideration the torque
characteristic of the motor /
driven load (e.g. synchronous
motor). V
P1325
f1
P1320
f
max
P1082
V
max
r0071
V
n
P0304
P1323
P1321
f0
0 Hz
f2
P1322
f3
P1324
f
n
P0310
f
P1300 = 3
P1310