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Φ
The flux values
(
I
fset
setpoints
are determined according to the formula defined below from the actual EMF
I
fset
and speed values calculated and measured respectively and entered in a table of flux values.
EMF
Φ
=
∗
(
I
)
100
%
fset
n
act
,
... measured values in field-weakening range at specified
EMF
n
act
act
,
EMF
n
rated
field
rated
field
Settings:
P102: Rated excitation current motor
Set P103 = 0, minimum excitation current motor
P613.01 = 401, parameter P401 specifies the factor for the excitation current setpoint
(x 0 – 100%).
P433.01 = 402, parameter P402 specifies the speed setpoint.
The speed setpoint must be set to a value lower than the rated speed of the motor. Start
recording at approximately 80% of the rated motor EMF.
Procedure: Maintaining a constant speed for the various settings of P401 (starting at 100%),
enter r037 and r025 in the table and calculate Φ (I
I
EMF
in % of
fset
I
field
rated
motor
P401
100.0 %
(rated field)
(=
EMF
91.0 %
83.0 %
76.0 %
70.0 %
65.0 %
60.5 %
56.5 %
53.0 %
50.0 %
47.0 %
44.0 %
41.0 %
38.0 %
35.0 %
32.0 %
29.0 %
26.0 %
23.0 %
20.0 %
17.0 %
14.0 %
11.0 %
8.0 %
normalized to rated flux which are reached at specific field current
)
n
∗
rated
field
act
... in field-weakening range at specified
EMF
rated
field
... measured values with rated field (100.0 % rated excitation current)
=
n
act
act
r037
r025
(=
)
rated
field
n
rated
field
).
fset
Φ
(
I
)
fset
acc. to formula
above
100.00 %
)
2
I
fset
I
fset
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