Compact, modular design for precise control of multiple-motor applications begins rollout to markets around the world
NEW BERLIN, Wis., September 9, 2004 The new ABB multidrive ACS800 family, based on a modular configuration of dramatically smaller inverter modules, is now being introduced to end users throughout North America.
Compact Flexibility
--The modular configuration of the ACS800 multidrives provides control of multiple motors across a 1-7,000 HP power range, from 380-600 (690) VAC. A single rectifier unit can be combined with a host of inverter units that are connected in parallel, to provide output current required by any given application.ABB's multidrive is built from industrial drive modules that are connected to a common DC bus bar. The common bus bar is used to supply the drive modules with DC power, and each module then inverts the DC to AC and powers an individual motor. The DC power is derived from a single supply unit (rectifier) that is built into the front of the same multidrive configuration.
The standard DC bus arrangement enables single power entry and common braking resources for several drives. "Common braking includes regenerative braking and motor-to-motor braking depending on the demands and modes of the various motor loads in a process or on an original equipment machine," according to Jari Tukia, product manager for multidrives, ABB Drives.Modular construction simplifies the total installation and results in manybenefits: savings in cabling, installation and maintenance costs; reduced line currents and simpler braking arrangements; energy distribution over the common DC bus bar, which can be used for motor-to-motor braking without the need for a braking chopper or a regenerative supply unit; reduced component counts; increased reliability; and space savings.
Footprint Reduced 50 Percent
--Individual inverter modules used in the multidrives' construction are dramatically smaller - many only one-third the size of the generation of modules preceding them. Improvements in technology and these power components have reduced the total footprint of these ACS800 multidrives by up to 50 percent, compared to the previous generation of units, Lindgren said. This frees up significant wall-, panel- and floor-space for the integrators, OEMs, panel builders and end users that utilize multidrives." These multidrives should be used whenever several drives/motors form part of a single or integrated mechanical process," said Tukia.
The common supply of the multidrive enables the implementation of overall safety and control functions, and permits the close coordination of individual drive motors. For example, a paper machine has many motors that must be individually controlled as a complete system. The ABB multidrive drive modules offer fast communication of torque and speed signals between the drives, to control the tension in the paper web, he noted.Multidrives also can be used where the shafts of the individual drive motors are not tightly coupled; for example, in sugar centrifuges, each drive module can be programmed with a speed profile so that the overall use of energy from the grid is minimized.
These two examples merely demonstrate the range of applications where ABB multidrives offer substantial benefits over other types of drive constructions. Set-up and Control - Fast and Easy! --The new multidrive rectifier module and DC-supplied inverter units (which began at 200 HP) include an extensive selection of user-friendly features for easy set-up and control. The three-phase power cabling is wired to a rectifier module through a unique new plug-in connector, which powers the entire common DC line-up. The connector for the rectifier includes the AC-in, DC-out, and controls.
And the plug-in connectors for the inverters (150 HP and up) are wired to the motor terminals.The motor cabling is connected to the plug-in connectors, which project inside the multidrive cabinetry; this makes access easy for electrical personnel wiring power to/from the plug-ins. Both the rectifier and DC-supplied inverter modules are equipped with wheels, so they can be pushed into the cabinetry and seated into the connectors easily. The modules also can be rolled out of the cabinet for quick access and maintenance.The new multidrive concept also includes a modular control unit (availableseparately) that houses an AC800M and S800 I/O PLC controls for virtually any process.
This control unit is equipped with communication interfaces, power supplies and all the front-end-devices for precise control of automation equipment. The multidrives are backward compatible with ABB's previous ACS600 family. Additional set-up and control features/benefits built into the new drivesinclude: -- Direct Torque Control (DTC) -- fast, accurate and protective motor control method, proprietary to ABB, eliminates the need for installing encoders in most applications, and enables the drives to calculate the state (torque and flux) of the motor 40,000 times per second.-- I/O, Field buses -- I/O extensions, field buses and a pulse encoder module all fit inside the inverters.
Control features also include low audible noise, high motor load-ability, and flying restart of motors.-- Start-up Assistant and Adaptive Programming - standard interactive tools provide for dramatic time- and cost saving in commissioning. Start-up Assistant automatically detects when the drive is turned on for the first time and then provides guided start up, step by step; no need to worry about which parameters to set. And Adaptive Programming extends further the freely programmable I/O and extensive parameter selections for complete flexibility. Few Modules, Big Power --A minimum type and number of modules is required to provide precise control of large-power applications.
Only four different types of diode rectifier units cover the entire multidrive power range from 180-4200 kW (250HP-5600 HP) in 380-600 (690) VAC.Standard features built into these diode rectifier units include built-in adaptation to 6- or 12-pulse operation, and automatic control to pre-charge the inverter capacitor banks during start-up. And a fully regenerative IGBT Supply Unit with a power factor 1 requires no power compensation. The unit also can boost motor voltage when the line voltage is low.
The DTC control and LCL filtering in the rectifiers also keep harmonics at extremely minimal levels.Inverter modules are available in seven different frame sizes (R2i-R8i), across a 1 - 7,000 HP power range, in 380 ? 600 (690) VAC.
From 150 - 7,000 HP, the modules are different configurations of R8i frame-size units, added in single or parallel configurations (parallel connection starts above power requirements of 600 HP).Also built into ABB's multidrive ACS800 family are the following standard features/benefits; these are unique in drives and are not available in previous generation ABB drives, or in existing competitors' drives:- Built-in redundancy through parallel connected modules; each module is a complete three-phase inverter;- Enables running with partial load if one module fails in parallel connection; and- Provides for higher drive availability and greater process uptime."
Compact and Easy - those are the watchwords to describe the entire ACS800 series of stand-alone industrial drives and these new multidrives," said Tukia. "They demonstrate how technology is enabling us to add more and more features into a shrinking space and make the benefits they provide easier and easier to install, access and use." ABB ( www.abb.com ) is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact.
The ABB Group of companies operates in around 100 countries and employs about 105,000 people. The company’s U.S. subsidiary employs about 8,500 people in manufacturing and other facilities in 32 states.
