Vacon NX series User Manual

Active Front End (AFE) vacon • 21
Local contacts: http://drives.danfoss.com/danfoss-drives/local-contacts/
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 5, 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 6.
Figure 5. 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 series Specifications

General

Product type	AC Drive
Output voltage range	0-Uin
Frequency range	0-500 Hz
Enclosure classes	IP00, IP21
Mounting types	Wall
Braking chopper	Integrated or external
EMC filter	Built-in or external
Control modes	Scalar, Vector
Protection features	Overcurrent, overvoltage, undervoltage, overtemperature, short circuit
Communication options	Modbus, Profibus, CANopen, Ethernet
Ambient temperature range	-10°C to +50°C
Cooling method	Air-cooled