Posted to News on 18th May 2016, 12:44
Regenerative DC motor control for heavy industry applications
Sprint Electric is presenting its extended range of digital DC drives up to 2250A. The drives of the PLX range are suitable for controlling DC motors used in heavy industry applications such as metal working, steel mills, mining, or the cement, rubber and plastics industries. PLX drives are able to regenerate energy back to the mains supply under braking without the need for expensive, complex intermediate storage, resistive dumping or additional power bridges. Available in current ratings up to 2250A at supply voltages up to 690V AC, the motor controllers are compact, powerful, flexible, and easy to programme thanks to the drive.web control technology.
DC drives of the PLX range are available as two quadrant or regenerative four quadrant types. The four quadrant model uses two thyristor bridges to enable it to motor and brake in both directions of rotation. This allows it to reverse the torque to slow the load very gently or almost instantaneously, regenerating energy at the same time. Unlike an AC drive, it is able to generate full torque at zero speed, enabling the load to be held stationary in complete safety without the need for mechanical brakes, an especially useful feature for winders and hoists. This ability means DC is also suitable for applications such as mixers, extruders and rollers that require high starting torques and accurate control at low or zero speed, as well as for paper machines, wire drawing and machining.
All models ranging from 650 to 2250A (980KW/1320HP) are offered with two AC busbar position options, either top entry or bottom entry. The two options make it easier to use the existing cabling in retrofit installations, or give the choice of wiring options for new design. The PLX range is available as high voltage (690V AC) or standard voltage (480V AC) models. A 690V AC supply allows the use of 750V DC armature motors. Compared with the standard voltage this provides an increase in shaft power, up to 1500KW/2000 HP for the 2250A model; that is 50 per cent more power delivered without an increased cable size.
Thanks to the control technology drive.web, the drives can be controlled over the Ethernet without the need for a PLC or supervisory computer. The control system includes graphical configuration tools that provide diagnostics and configurability of all drives on the network, either locally or remotely via the Internet. The graphical tools allow the full configuration of the drives, provide service diagnostics, full documentation and an operator interface for local control. Software functions and fieldbus communications options include Profibus, DeviceNet, CC-Link, EtherNet/IP, Modbus and CANopen.
Sprint Electric offers a wide range of DC motor control, with over 150 models covering both 1 phase and 3 phase, regenerative and non-regenerative DC motor applications, together with field controllers, digital slip ring motor controllers and thyristor stack controllers. Sprint Electric's full range of products include analogue DC drives from 2 up to 330A, digital DC drives from 12 up to 2250A and digital slip ring motor controllers from 12 to 1680A. Whether in retrofits or original equipment, DC drives from Sprint Electric are being used in many different applications including metal processing, the pulp and paper industry, rubber and plastic processing, lifting equipment, food processing, leisure industries and many more.
For more information about the PLX range of digital DC drives please visit www.sprint-electric.com.
