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INSTALLATION AND WIRING
3) Harmonic suppression technique requirement
If the outgoing harmonic current is higher than the maximum value per 1kW (contract power) × contract
power, a harmonic suppression technique is required.
4) Harmonic suppression techniques
No. Item Description
1
Reactor installation
(ACL, DCL)
Install a reactor (ACL) in the AC side of the inverter or a reactor (DCL) in its DC side or both to
suppress outgoing harmonic currents.
2
High power factor
converter
(FR-HC)
The converter circuit is switched on-off to convert an input current waveform into a sine wave,
suppressing harmonic currents substantially. The high power factor converter (FR-HC) is used
with the standard accessory.
3
Installation of power
factor improving
capacitor
When used with a series reactor, the power factor improving capacitor has an effect of absorbing
harmonic currents.
4
Transformer multi-
phase operation
Use two transformers with a phase angle difference of 30° as in -∆, ∆-∆ combination to provide
an effect corresponding to 12 pulses, reducing low-degree harmonic currents.
5 AC filter
A capacitor and a reactor are used together to reduce impedance at specific frequencies,
producing a great effect of absorbing harmonic currents.
6 Active filter
This filter detects the current of a circuit generating a harmonic current and generates a harmonic
current equivalent to a difference between that current and a fundamental wave current to
suppress a harmonic current at a detection point, providing a great effect of absorbing harmonic
currents.
