AC Drives Provide Extremely Precise Motor Control and Save Encoder Costs Through Direct Torque Control (DTC) Technology; Embedded Drive Applications Control Center Winder and Inline Tension Control
“The ACS 600 drive family has anticipated the shift worldwide to AC motor control in virtually all processing applications,” said Chuck Hollis, director of industrial sales, ABB Automation Inc., Drives & Power Products Group, New Berlin, Wisconsin. “Such a family creates an ‘easy-to-use commonality’ throughout all the models, including a common drives platform, similar operator control panels, pre-programmed macros, advanced application software -- and share installation, start-up and maintenance features,” he noted. “End-users get ease of installation, operation and control performance that a decade ago was unimaginable.”
The ACS 600 also is ideal for powering AC motors in general purpose production applications such as pumps, fans, and factory automation systems. The drive provides direct speed and torque control without an encoder or tachometer (required by other drives to feed back motor shaft speed or position).
Direct Torque Control; Embedded Applications
ABB introduced the ACS 600 single drive series with it’s unique Direct Torque Control (DTC) in 1995. This open loop DTC feature, which enables the ACS 600 to calculate the state (torque and flux) of a motor 40,000 times per second, makes the drive trip-less. “Because this open-loop control of torque is so precise, the ACS 600 can adapt to and handle rapid changes in load, over/under voltages, and even short circuits, immediately,” said Hollis. “This rapid response to load changes make this drive ideal for operation of process lines, many of which require consistent and constant speed or tension throughout the production process.”
ABB’s proprietary Winder and Inline software utilizes this DTC technology to control product tension within a process by adjusting the speed or torque, based on Tension or Dancer feedback, or Draw Input. Through these embedded applications, the drives can be used as an extremely cost-effective solution for web-handling equipment such as film machines. ABB has more than 500 Center Winder and 1000 Inline Tension Control applications installed, respectively, on webs around the world.
ABB also has introduced a four-quadrant regenerative version of the ACS 600. “DTC enables the regenerative ACS 600 to go smoothly from maximum motoring and regenerating power and back again in milliseconds,” says Ron Dombrowski, product manager – AC Drives, ABB Automation Inc., Drives & Power Products Group. The active rectifier, together with DTC, ensures smooth operation in even the most demanding applications, he noted. The AC drive operates effectively during voltage dips, and it also provides extremely low line harmonics and energy savings when braking. All the components that are needed are in one unit and the regenerative drive as easy to use as the rest of the ACS 600 family.
Step-up/Sine Filter Package
ABB also provides a step-up/sine filter ACS 600 drive package, with the filter built in. The filter suppresses the high frequency components, giving a sinusoidal output waveform to the motor. The step-up drive can be used with step-up or step-down output transformers, allowing end users to cost effectively connect the drive package to virtually any motor voltage. “It can be used with no output transformer to protect old motors in retrofits, or in very long lead length situations where the motor would typically be damaged when using a standard AC drive,” comments Dombrowski.
Built-in Macros Ease Application Programming
The ACS 600 has a library of built-in application macros that simplify programming. This provides, at the touch of a button, a pre-programmed selection of control configurations (inputs, outputs, signal processing, and other parameters) for typical applications. This ranges from simple three-wire start-stop and speed reference control, to a PID macro to control a process variable, to a sequential macro for batch mode control. An easy-to-configure lead/follower macro is also included in the ACS 600 for lead/follower systems.
The nine-language alphanumeric control panel allows for quick customization without the need for look-up codes and a manual. The display simultaneously shows three different values, such as speed, frequency, current, torque, power or voltage. The control panel also has a convenient feature that enables all drive parameters to be copied from one drive to another to simplify start-up. Only one control panel is needed to program multiple drives.
“The common drives platform for the ACS 600 family standardizes parts and is very user friendly,” says Dombrowski, “because an operator needs training only once to be able to work with any ACS 600 family drive in their facility. It doesn’t matter if it’s on an injection molding machine, pump, or an extruder, the basics are the same.” This saves training dollars and reduces downtime.
Supporting the Life-cycle of Drives
ABB also supports the overall performance of its drives with a comprehensive range of software tools. The suite of user-friendly tools that support the ACS 600 make it easy to work with many different ABB drives within the same facility. These Windows-based tools optimize sizing, engineering, ease start-up and maintenance support of drive systems. Tools for the ACS 600 drives family include: