Case Application: Delta s Power Regenerative Unit for Overhead Bridge Cranes Issued by Solution Center Date May, 2013 Pages 5 Applicable to Key words AC motor drive, REG2000 Crane, hoist, Delta AC motor drive, reliability, REG2000, quick braking, brake resistor, current control PWM converter, switch rectifier, energy-saving, energy regeneration Introduction Delta s REG2000 Power Regenerative Unit collects excess energy generated by an overhead bridge crane and converts it into reusable electricity It is as simple to install as a brake resistor, while one-half the size, and it does not require an additional heat dissipation device A bridge crane (also known as an overhead traveling crane) can be found in warehouses, factories, docks, open storage yards, and many other open spaces To facilitate operation efficiency and reduce malfunction rates, using a three-phase induction motor for a crane system provides many advantages, including a simple structure, high durability, low cost, and ease of maintenance Using an AC inverter to control the induction motor would further limit the malfunction rate for more precise operation When the bridge crane is in operation, it generates excess regenerative energy that is usually consumed by using brake resistor to keep the system stable and safe If the crane system uses a power regeneration unit such as the REG2000 instead of a brake resistor, the regenerative energy can be collected more efficiently and converted into reusable electricity for other facilities to use Background Today, many systems use inverters to perform different tasks and generate large load inertia or excess regenerative energy that must be consumed to maintain the DC Bus voltage at a safe level Applications include the main spindle motion of a machine tool and a centrifuge system while performing prompt deceleration or braking control, and also include elevators, cranes, and winding machines that generate large amounts of regenerative energy while loading heavy goods A traditional solution is to install a brake resistor to dissipate all the excess energy as heat until it disappears This is a quick solution with benefits that include easy wiring and low construction cost but it requires a larger space and the installation of an additional heat dissipation device, while the energy dissipation result is not 100% Delta s REG2000 Power Regenerative Unit is as simple to install as a brake resistor, while one-half the size and it does not require an additional heat dissipation device The most outstanding feature is that the excess energy is now collected and converted into reusable electricity - 1 -
Application Delta s REG2000 Series The REG2000 is a general-purpose power regenerative unit that follows the four quadrant design concept of the AFE2000 While the AFE2000 Series improves power factor, harmonics treatment and power regeneration, the REG2000 focuses on power regeneration The REG2000 is developed for customers whose special needs target purely on the excess energy problems of an inverter system The Delta REG2000 Power Regenerative Unit is an ideal green product that provides energy-savings with power regeneration and excellent performance - 2 -
REG2000 Series Features 1 The PWM control provides low harmonics and high power factor while converting regenerative energy into reusable electricity 2 Compact, easy to install with 6 wiring connections 3 Built-in reactor, space-savings of up to 50% 4 A substitute for brake resistors that reduces heat and achieves substantial energy-savings with power transformation efficiency above 95% 5 Improves braking ability up to 150% compared to a traditional brake resistor that provides only 125% 6 Built-in MODBUS RS-485 communication, real-time display of energy saved in KWh and cost in dollar units 7 Excellent installation flexibility that is compatible with all brands of inverters and servo drives 8 Certified by CE/UL/cUL with safety ensured Comparison of REG2000 and AFE2000-3 -
Test Results Delta s REG2000 series provides the ultimate in performance and high efficiency for bridge crane applications - 4 -
Delta s AC motor drives are known in the industrial automation market for excellence in electronics technology and rapid innovation Incorporating an AC motor drive with the recently released Power Regenerative Unit, REG2000 Series, for bridge crane systems would provide an additional energy savings of up to 30% The REG2000 series is easy to install and is equipped with a self diagnosis function that facilitates the maintenance process The power regeneration function helps to bring down the system operation cost and provide users with a greater competitive advantage in the market For more information on Delta s AC motor drives, please visit our website at: http://wwwdeltacomtw/ch/product/em/drive/ac_motor/ac_motor_mainasp - 5 -