Internal Component Functions - Danfoss VLT AQUA Drive FC 202 Instruction Manual

Introduction

1.4 Internal Component Functions

1 1
Figure 1.3 is a block diagram of the adjustable frequency
drive's internal components. See Table 1.3 for their
functions.
Figure 1.3 Adjustable Frequency Drive Block Diagram
Area
1 Line power input
2 Rectifier
3 DC bus
4 DC reactors
5 Capacitor bank
6 Inverter
7 Output to motor
1-4
VLT
Instruction Manual
Title Functions
•
Three-phase AC line power
supply to the adjustable
frequency drive
•
The rectifier bridge converts
the AC input to DC current to
supply inverter power
•
Intermediate DC bus circuit
handles the DC current
•
Filter the intermediate DC
circuit voltage
•
Prove line transient protection
•
Reduce RMS current
•
Raise the power factor
reflected back to the line
•
Reduce harmonics on the AC
input
•
Stores the DC power
•
Provides ride-through
protection for short power
losses
•
Converts the DC into a
controlled PWM AC waveform
for a controlled variable
output to the motor
•
Regulated three-phase output
power to the motor
MG20M922 - VLT
®
AQUA Drive
Area
8 Control circuitry
Table 1.3 Legend to Figure 1.3
®
is a registered Danfoss trademark
Title Functions
•
Input power, internal
processing, output, and motor
current are monitored to
provide efficient operation
and control
•
User interface and external
commands are monitored and
performed
•
Status output and control can
be provided