23-05-2012, 03:41 PM
Low Voltage Roller Table Motors
Roller Table Motors.pdf (Size: 3.17 MB / Downloads: 21)
Motors and frequency converters
ABB meets the demands of the rolling mill environment
by combining the expertise of two areas within the
Group. By bringing together squirrel cage motors from
ABB Motors and frequency converters from ABB Drives,
ABB can supply electrical drive systems that are
tailored to the needs of the industry.
ABB Motors has been developing and growing for
over 100 years and is today one of the world’s leading
manufacturers of low voltage induction motors. It
supplies a full range of industrial electric motors,
meeting the needs of most applications with virtually
any power rating. At the same time it provides solid
value and commitment to its customers through
unrivalled service and back-up.
Roller table drives
Roller tables incorporate a number of motors, the speed
of which can be steplessly controlled by one or more
frequency converters.
The rolling mill environment places severe stress on
roller table drives. As plates and billets travel along
the roller table at high speeds, the motors driving the
rollers are subjected to high torque loads. At the same
time, the reliability of the drive system is constantly
threatened by the high ambient temperature, humidity,
and the risk that fine dust particles from the process
could infiltrate the motors.
To meet these rigorous demands, ABB has developed
its Roller Table AC Drive System, which comprises the
new, robust M3RP induction motors, together with ABB
frequency converters.
The totally enclosed construction of the M3RP induction
motors renders them immune to the ingress of moisture
and dust. The power factor of ABB frequency converters
with IGBT supply units is 1.0 under any load conditions.
Together the motor and frequency converter provide a
competitive solution, with high availability and minimal
maintenance costs.
Frequency converters
A single AC drive system typically consists of an input
transformer or an electric supply, frequency converter,
AC motor, and load machine. The single frequency
converter consists of a rectifier, DC link and inverter.
Benefits of ABB multidrive frequency converter
– reduced line currents and simple braking
arrangements
– energy circulation over the common DC busbar, which
can be used for motor-to-motor braking without the
need of for a braking chopper or regenerative supply
unit
– reduced component count and increased reliability
when a common supply and DC link are used
– reduced cabling due to the single power entry for
several drives
– savings in cabling, installation and maintenance costs
(the supply and inverter modules, for example, are
fitted with plug connections for fast and easy module
changing)
– space savings through modular construction (space
savings up to 60% compared to the previous
generation of ABB multidrives)
– overall safety and control functions made possible by
the common supply.
Built-in redundancy
The inverter section of the ACS800 multidrive consists
of three-phase modules. The modules – each of which
is a complete three-phase inverter – are connected
in parallel according to the motor power requirement.