Siemens SINAMICS S150 NEMA, Руководство по эксплуатации

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Functions, monitoring and protective functions
9.3 Drive functions
Enclosed Drives
Operating Instructions, 12/2018, A5E36652151A
547
9.3.12 Derating behavior at increased pulse frequency
Description
To reduce motor noise or to increase output frequency, the pulse frequency can be
increased relative to the factory setting.
The increase in the pulse frequency normally results in a reduction of the maximum output
current (see "Technical data/current derating depending on the pulse frequency").
When commissioning the converter the behavior at overload is adjusted in such a manner
that the pulse frequency is variably reduced so that the required power can be obtained.
Characteristics:
● The reaction to overload depends on the setting of parameter p0290:
–
p0290 = 0: Reduce output current or output frequency
– p0290 = 1: No reduction, shutdown when overload threshold is reached
– p0290 = 2: Reduce the output current or output and pulse frequency (not using I²t).
– p0290 = 3: Reduce the pulse frequency (not using I²t)
● With p0290 = 2, for overload, the pulse frequency (and consequently the output
frequency) is first reduced until it has dropped to rated pulse frequency; then the output
frequency is reduced if overload continues to persist.
The rated pulse frequency is half the inverse value of the current controller clock cycle:
0.5 x 1/p0115[0].
● The pulse frequency is reduced in whole multiples based on the rated pulse frequency
(5 kHz -> 2.5 kHz -> 1.25 kHz or 4 kHz -> 2 kHz).
● After entering the maximum speed in p1082, the system automatically calculates whether
the pulse frequency is sufficient for the entered maximum speed, if necessary the pulse
frequency is increased automatically to a value that is necessary to achieve this.
For an overload condition, also for p0290 = 2 or 3, this new pulse frequency will no longer
be fallen below, the subsequent response (reduce output voltage or shutdown) is
triggered.
Exceptions:
● With an activated sine-wave filter (p0230 = 3, 4), this behavior is not permitted because
the pulse frequency set in the factory (2.5 kHz or 4 kHz) may not be changed.
Consequently in this case the selection possibility for the parameter p0290 is limited to
"0" and "1".
Activation of the variable pulse frequency
At commissioning the parameter p 0290 is automatically set to the value "2". This activates
pulse frequency reduction at overload.