ABB has made a belated entry to the servo drives sector with the ambitious aim of capturing 10% of the $1.78bn global market by 2010. The company has invested around $15m and devoted more than 150 man-years of engineering effort to develop its new Machinery Drive — first seen at the recent SPS/IPC/Drives show in Germany.

ABB has now revealed more details about the modular drive, and how it plans to capture a substantial slice of the servo drive business. If it hits its 10% target, ABB will probably become one of the world`s top three servo drive suppliers. In 2005, Mitsubishi and Yaskawa each had about 12% of the global market, followed by Siemens on 10% and Bosch Rexroth on 7%, according to the market analyst, ARC.

The Machinery Drive (shown above in various configurations) is being built on a new line in Finland which has the capacity to make 25,000 drives a month. Initially, it will span ratings from 0.75-45kW, but there are already plans to extend the range. The drive is based on standard AC drive technology, enhanced to give servo performance. It uses a new version of ABB`s 11-year-old DTC (Direct Torque Control) technology.

ABB claims the Machinery Drive is the most adaptable on the market, with the ability to control induction, synchronous and asynchronous servo and torque motors, in open or closed loop configurations. "Machine builders only need to specify one drive for a variety of motor types," says ABB principal engineer, Steve Moore. "It will work with any type of motor from any manufacturer." All that the user needs to do is to enter the motor`s nameplate data.

The drive consists of a power module (available in several ratings), a control module, and plug-in sub-modules for various feedback and communications options. The control program and data are stored on removable memory modules, which OEMs can encode to protect their know-how. If either the power or the control modules need to be replaced, the drive can be re-commissioned simply by re-inserting in the memory module.

The modular design will allow OEMs to add dedicated functions and programs to a machine before they despatch it to a customer. The optional fieldbus, I/O and feedback interfaces can be configured in the machine-builder`s workshop, at a local distributor, or on a customer`s site.

The Machinery Drive supports either distributed motion control, or centralised position control from a motion controller. It offers positioning and synchronisation control to 500µs, making it suitable for most machinery applications. Reference handling inside the drive is configurable from 250µs.

"The design team set out to ensure that each core software and hardware element supported each other`s performance," explains Steve Ruddell, general manager of ABB`s drives and motors business in the UK. "For example, if we have a control loop within the speed controller running at 250µs, then both I/0 or incoming signal and encoder or speed feedback sampling supports the same 250µs loop. Reference signals will not be lost."

The drive keeps DTC`s energy-saving flux optimisation feature, which means that it can be used to control not only machinery, but also auxiliary applications such as pumps and fans. Customers will able to use the same user interface, spare parts and training for these different applications. According to ABB, traditional servo drives cannot be used to control pumps and fans because they need feedback devices.

Another DTC facility in the new drive is support for flying starts, which is said to be particularly useful in continuous process applications where even short interruptions can result in costly downtime. The drive`s various speed feedback options are said to improve the flying-start performance, while its fast torque control allows it to recover control rapidly when the power returns.

The Machinery Drive`s plug-in interface modules (shown above, left, with control and memory modules) allow it to be used with a range of feedback devices, including resolvers and absolute or incremental encoders. The modules have built-in intelligence in the form of microprocessors or FPGAs (field programmable gate arrays) that process signals from the feedback devices. This information can be used to fine-tune the DTC motor model, thus enhancing its control of speed, torque and position.

Interface modules are available for the Profibus, DeviceNet, CANopen and Ethernet bus protocols — with a Sercos version in the pipeline. The modules incorporate microprocessors or custom chips which process the bus signals and transfer them via a fast internal link to the control software.

The I/O sampling system can vary the sampling time of each I/O and prioritise the sampling to optimise the load on the drive`s main processor. The time delay from a control reference change to a motor shaft torque change is claimed to among the fastest on the market.

ABB`s Steve Ruddell is confident of hitting the 10% penetration target in the UK motion market which, according to the market analyst Frost & Sullivan, was worth £47m in 2004, with Siemens holding an 18.7% stake, followed by Bosch Rexroth on 16%.

Servos account for about 37% of the number of drives sold in the UK at present (with AC drives accounting for 52% and DC drives for the remaining 11%). Servo sales are growing by about 5% a year — the fastest of the three segments — and this growth rate is predicted to increase as servos become even more widely used, and as prices drop.

"All I can see is opportunity," says Ruddell. "It`s a critical sector that we must break into. We want some of the £47m pie." He acknowledges that he will probably lose some standard drives sales to the new servo range.

Initially, ABB is targeting sectors such as food and beverage, materials handling, packaging, textiles, rubber and plastics, and printing. In a second phase, it will attack applications such as high-end machine-building and robotics.

ABB has created a dedicated team to develop the servo market in the UK and plans to appoint about half-a-dozen specialist systems integrators. Unlike ABB`s existing DrivesAlliance network for standard AC drives, the new network will consist of specialists in particular industries, rather than being split geographically. The SIs will be appointed on a non-exclusive basis.

Ruddell promises that the new Machinery Drives will be "competitively priced". There will be a matching series of servo motors made by ABB Italy.