Nx Networks NX series ユーザーズマニュアル

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Technical data
4
4. TECHNICAL 
DATA
4.1 Introduction
Figure 4-1 presents the block diagram of the NX frequency converter. The frequency converter
consists of two units, the Power Unit and the Control Unit.
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 frequency converter to the
mains. It, in addition, enhances the waveform of the input current to the frequency converter. The
entire power drawn by the frequency converter 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.
Figure 4-1. NX block diagram
=
=
L 1
L 2
L 3
U
V
W
3~
3~
NK4_1
Mains
Motor
Brake
Chopper*
Measure-
ments
Gate
Drivers
Motor
Control
ASIC
Motor and
Application
Control
Control
Keypad
Fan
Current
Sensors
Rectifier
IGBT
Inverter
Brake resistor*
Output
EMC-
filter
Power
Supply
Control
     I/O
Control
     I/O
Control
      I/O
Control
     I/O
Control
     I/O
Voltage
Sensors
NXP
1)
2)
3)
Integrated input module
*Brake resistor is available  as optional equipment  for all classes  (FR4  to FR8).
However, the brake resistor  can be installed internally  in classes FR4 to FR6 and  is  installed
externally in classes FR7 and greater.
Brake  chopper belongs to the standard equipment  in classes  FR4 to FR6,  while in greater classes
(FR7/FR8) it is optional.
Control
module
Power
module
Charg.res.