Electrical switching & drive systems & components


Electronic variable speed drive systems

March 2011 Electrical switching & drive systems & components

Through the recent acquisition of Velo Control, BMG Drives has extended its product portfolio to include Danfoss variable speed drive systems.

The Danfoss range, which encompasses dedicated pump controllers, provides efficient pump performance in applications where a certain pressure or level needs to be maintained over a wide dynamic range. Danfoss pump cascade controllers, with features and functions that eliminate the need for PLCs and other external controllers, increase the efficiency of multiple pump or blower systems. These dedicated controllers ensure accurate flow, pressure and level control. This results in a lower energy consumption compared to valve throttling or the conventional across the line on/off cycling of pumps and blowers.

Cascade controllers allow staging of up to four additional drives and/or fixed speed motors. Using the master drive’s PID controller, the system provides precise control in large pumping systems. Other important features include minimal wear on driven equipment, enhanced energy savings and optimum productivity in diverse sectors.

Lead pump alternation functionality distributes running time equally across all connected pumps, ensuring optimum efficiency of the system. Wear on individual pumps is minimised and the service life of each pump is extended.

These cascade controllers also operate pumps of unequal size and are available with master/slave cascade control. The master drive controls the speed and staging on or off of the additional adjustable speed slave drives.

Running a large pump at variable speed over a wide dynamic range is not an ideal solution because of low pump efficiency. Also there is a practical limit of approximately 25% rated full load speed for running a pump. In the basic cascade control, the drive controls a variable speed motor as the lead motor and can stage up to two additional constant speed motors on and off. By varying the speed of the initial motor, variable speed control of the entire system is provided. This maintains constant pressure, eliminating pressure surges and resulting in reduced system stress and quieter operation in pumping systems. The basic cascade controller can control up to three equal size pumps, with lead pump alternation to equalise pump run time and wear. This has application in pressure booster stations, where fixed speed pumps are started and stopped as required, while the speed controlled pump or fan is utilised to match the exact flow demand, keeping the system pressure constant.

The extended pump cascade controller is available with three additional relays and the advanced controller has the option of eight additional relays.

For more information contact Dave Dyce, BMG, +27 (0)11 620 1530, [email protected], www.bmgworld.net



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Precise detection of complex rotational movements
Beckhoff Automation Electrical switching & drive systems & components
The EP3751-0260 EtherCAT Box module by Beckhoff connects an acceleration sensor with an inertial measurement unit - a gyroscope. This provides accurate detection of acceleration and rotational motion in addition to shock, vibration and tilt measurement, both as preprocessed values and as raw sensor data.

Read more...
Energy management system for electrohydrostatic actuation systems
Electrical switching & drive systems & components
In the machine manufacturing industry, more drive systems are being converted from servo-hydraulic throttle to electrohydrostatic actuation systems. The four-quadrant capability of the electrohydrostatic pump unit and servo drive used in this technology, in combination with the new Moog energy management system, allows regenerative power flows generated during braking or pressure relief to be stored and reused.

Read more...
Drive solution for stacker reclaimer
Electrical switching & drive systems & components
Hägglunds Drives South Africa recently completed a retrofit project on the bucket wheel of a stacker reclaimer at Richards Bay Coal Terminal. The project entailed replacing a gearbox drive solution with a direct drive solution from Hägglunds Drives SA.

Read more...
Kamoa-Kakula power pack order for SEW-EURODRIVE
SEW-EURODRIVE Electrical switching & drive systems & components
With well over 100 units already delivered, SEW-EURODRIVE is set to continue supplying Ivanhoe Mines’ prestigious Kamoa-Kakula Copper Complex in the Democratic Republic of Congo.

Read more...
Seven ways to reduce production downtime on the plant
Electrical switching & drive systems & components
Production downtime is one of the biggest risks in the manufacturing industry. Follow these seven tips to reduce machine downtime in your production line.

Read more...
The time is now to implement a motor management strategy
Schneider Electric South Africa Editor's Choice Electrical switching & drive systems & components
Motor management plays an all-important role in controlling motor energy costs in various industries, segments and applications. Research and practical experience have consistently shown that effective motor management practices can result in significant energy savings, reduced operational costs, and improved overall system reliability.

Read more...
Rapid overhaul of compressor motors
ACTOM Electrical switching & drive systems & components
Marthinusen & Coutts Zambia was requested by a smelter based in the Copperbelt to provide an in-country repair solution for its two critical 4,5 MW compressor motors. The company was given only three weeks in which to overhaul and commission the motors.

Read more...
PC-based motion control on a labelling machine
Beckhoff Automation Editor's Choice Electrical switching & drive systems & components
For 50 years, Bausch+Ströbel in Germany has been developing packaging and production systems for the pharmaceutical industries. The company’s goal is to offer the best technical and economical solutions for the challenges of modern industry. Its new ESA1025 labelling machine shows how this is achieved with PC-based control from Beckhoff as the central motion controller.

Read more...
Thrust for hybrid electric flying
Editor's Choice Electrical switching & drive systems & components
Several leading academic institutes in Germany are collaborating on the future of hybrid electric flying. The partners are researching an entirely new propulsion system for medium-range aircraft with up to 35 passengers.

Read more...
Precise knowledge for precise applications
Electrical switching & drive systems & components
Aerotech has been supplying standard product solutions such as motors, drives, controls and positioning tables since 1970. Customised motion subsystems include positioning systems on granite structures with undercarriage and vibration isolation, and also external measurement systems.

Read more...