ABB claims that it is the first manufacturer to put high-speed, low-voltage motors into serial production. Until now, such motors have been made only in limited quantities, mainly for test and prototype purposes.

ABB argues that the technology and the markets for high-speed motors have developed to the point where they are now a viable alternative to standard motors and gearboxes. Initially, it plans to produce "hundreds" of motors rated at up to 730kW, designed to operate at 3,000-14,000 rpm with air- or water-cooling.

Speeds of up to 60,000 rpm are possible, compared to the 3,000-750 rpm achievable with standard low-voltage induction motors (from two-pole to eight-pole).

High-speed motors eliminate the need for gears or belt drives, and are said to be compact, efficient, easy to install, and to require less maintenance than conventional motor-gearbox combinations. Potential applications include compressors, fans, and pumps.

To achieve good speed control of a high-speed motor, a frequency converter is needed. Using special software, ABB`s converters convert a standard frequency of 50 or 60Hz to 300Hz. The converters are said to provide accurate speed control and to allow soft starting and stopping.

ABB has tackled potential problems such as vibrations and over-heating with a combination of mechanical and electrical techniques. For example, it uses rolling element bearings and specifies hybrid bearings for some applications. At speed up to about 6,000 rpm, grease is used as the lubricant; at higher speeds, oil is used.

"We believe that the rising customer demand for high-speed applications can be met with a modular motor, rather than one requiring application-specific engineering," says Steve Ruddell, ABB`s general manager for electrical machines in the UK. "While a certain degree of customisation may be needed, depending on the maximum speed and application, our approach simplifies production, reduces the need for application engineering, and eliminates some of the non-standard solutions that, in the past, have been used to achieve high-speed operation."

The high-speed machines are being produced in a cell at ABB`s LV motor factory in Vaasa, Finland. A high degree of accuracy and cleanliness is needed, for example, to assemble the bearings. The cell will also be used to assemble other special motors, such as permanent magnet machines.