Danfoss AHF 010, Руководство по конструкции

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3.1.2 Capacitive Currents
If the specific application requires a higher power factor at
no-load and a reduction of the capacitive current in
standby, use a capacitor disconnect. A contactor
disconnects the capacitor at loads below 20%.
NOTICE
It is important to note that the capacitors must not be
connected at full load or disconnected at no load.
It is important to consider the capacitive current in the
design of applications where the harmonic filter is supplied
by a generator. The capacitive current can cause
overvoltage of the generator in no-load and low-load
conditions. The overvoltage causes an increase of the
voltage, which then may exceed the allowed voltage for
the filter and the frequency converter. Therefore, always
use a capacitor disconnect in generator applications and
consider the design carefully. For more information about
capacitive currents, refer to
chapter 4.2.1.1 Terminals for
Capacitor Disconnect .
Compared to multi-pulse rectifiers, passive harmonic filters
(such as VLT
®
Advanced Harmonic Filter AHF 005/AHF 010)
are more robust against background distortion and supply
imbalance. However, the performance of passive filters is
inferior to the performance of active filters when it comes
to part load performance and power factor. For details
about the performance positioning of the various
harmonic mitigation solutions offered by Danfoss, consult
the relevant harmonic mitigation manuals.
3.2 Energy Efficiency
For energy efficiency calculations see chapter 9.1 Energy
Efficiency .
Basic Operating Principle o... Design Guide
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