Inverter Drive Control; Overview Of Control - Mitsubishi Electric Melsec FX Series Beginners Manual

Inverter Drive Control

4.2 Inverter Drive Control
A frequency inverter, or inverter for short, is installed between the mains supply and the motor. An
inverter converts a fixed voltage and frequency into a variable voltage with a variable frequency.Thus
the speed of a asynchronous electric motor can be adjusted continuously.
In factory automation, inverters (sometimes known as variable frequency drives) are used to effi-
ciently control large current loads through voltage regulation to drive large fans, pumps or AC
motors. Drive control with inverters can lead to great reductions in energy consumption for a factory.
With a Mitsubishi general-purpose inverter connected to an FX
FX
3U(C)
by using limit switches, a basic positioning functionality is achieved. However, as described in section
1.3, the disadvantage to using an inverter to move a workpiece to a specific location is a loss in the stop
precision. Therefore, inverters should not be thought of as positioning controllers.
Important references for understanding inverter drive control for this section include:
● FX Series User's Manual - Data Communication Edition – (JY997D16901)
● Inverter Instruction Manuals
It is assumed that you will have read and understood the above manuals or that you will have them
close at hand for reference.
4.2.1

Overview of control

Programmable logic controllers and inverters communicate with each other through passing param-
eter data and control operation data back and forth. Inverters, when used for variable frequency drive,
require a frequency command and a start command to operate.
Mitsubishi's FREQROL Series inverters communicate with FX
PLCs via the Mitsubishi inverter computer link protocol to asynchronously control operations.
FX Positioning Control Systems
PLC, a motor can be controlled to move at a specific speed. Through monitoring feedback or
Learning to Use the FX Family for Positioning Control
, FX
2N(C)
, FX , FX
2N(C) 3G
, FX , FX , FX
3G 3GC 3GE 3S
, FX , FX and FX
3GC 3GE 3S 3U(C)
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or