Vacon NX Active Front End User Manual

Active Front End (AFE) vacon • 19
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4
4. ACTIVE FRONT END (AFE)
4.1 Introduction
The Vacon
®
NX Active Front End is used to transfer power between the AC input and intermediate
DC circuit. The Vacon NX Active Front End has a two-way function. This means that when power is
transferred from the AC input to the intermediate DC circuit, the Vacon NX Active Front End rectifies
the alternating current and voltage. When power is transferred from the intermediate DC circuit to
the AC input, the Vacon NX Active Front End inverts the direct current and voltage.
The difference between Vacon
®
NX Active Front End and other Front Ends is that the unit creates
low current distortion (THDI). In a typical Vacon NX Active Front End configuration, the desired
number of Inverters, Figure 7, are connected to the intermediate DC circuit.
The Active Front End configuration consists of the unit itself, LCL filter, pre-charging circuit, control
unit, AC fuses, main contactor (or circuit-breaker) and DC fuses, Figure 8.
Figure 7. Typical Active Front End configuration
NFE*
3
FFE*
3
2
3
INU
2
3
INU
2
3
INU
2
2
BCU
AFE*
* alternative
2 2 2
11168.emf
Common DC bus

Vacon NX Active Front End Specifications

General

Brand	Vacon
Model	NX Active Front End
Category	Controller
Language	English