Technical Data; Introduction - Vacon NX_ 0003 5 User Manual

TECHNICAL DATA

4.

TECHNICAL DATA

4.1

Introduction

Figure 4-1 presents the block diagram of the Vacon NX_ AC drive. The AC drive mechanically consists of
two units, the Power Unit and the Control Unit. Pictures of the mechanical assemblage on pages 55 to 63.
The three-phase AC-choke (1) at the mains end together with the DC-link capacitor (2) form an LC-filter,
which, again, together with the diode bridge produce the DC-voltage supply to the IGBT Inverter Bridge (3)
block. The AC-choke also functions as a filter against High Frequency disturbances from the mains as well
as against those caused by the AC drive to the mains. It, in addition, enhances the waveform of the input
current to the AC drive. The entire power drawn by the AC drive from the mains is active power.
The IGBT Inverter Bridge produces a symmetrical, 3-phase PWM-modulated AC-voltage to the motor.
The Motor and Application Control Block is based on microprocessor software. The microprocessor
controls the motor basing on the information it receives through measurements, parameter settings,
control I/O and control keypad. The motor and application control block controls the motor control ASIC
which, in turn, calculates the IGBT positions. Gate drivers amplify these signals for driving the IGBT
inverter bridge.
Mains
L1
L2
L3
PE
*The brake resistor can be installed internally in sizes FR4 to FR6 (NX_2 and NX_5). In all other
frames of voltage classes NX_2 and NX_5, as well as in all frames of all other voltage classes, the
brake resistor is available as option and installed externally.
Brake chopper belongs to the standard equipment in sizes FR4 to FR6, while in greater sizes
(FR7 to FR9) it is optional.
Figure 4-1 Vacon NX_ block diagram
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Power
module
1)
Integrated input module
Rectifier
3~
Charg.res.
Fan
Power
Supply
Control
Keypad
RS 232
Control
module
Control Control
I/O I/O
Brake resistor*
Brake
3)
Chopper*
IGBT
Current
Inverter
Sensors
=
2)
=
3~
Measure-
ments
Gate
Drivers
Motor and
Motor
Application
Control
Control
ASIC
Control Control Control
I/O I/O I/O
vacon • 17
Motor
U
Output
V filter
W
NK4_1
4