Patented air-cooled drive covers 500-3000hp

An Alstom Power Conversion product story

Edited by the Engineeringtalk editorial team Oct 11, 2000

The Power Conversion sector of Alstom has launched a new air-cooled addition to the Symphony drive family of medium voltage AC drives, which will make its first appearance at WEFTEC2000

The Power Conversion sector of Alstom has launched a new air-cooled addition to the Symphony drive family of medium voltage AC drives.

The drive will make its first appearance at WEFTEC2000, the Annual Conference and Exposition of the Water Environment Federation to be held in Anaheim, California.

The first air-cooled Symphony drives were developed for use in the Americas.

For this market, the whole range of drives will be US manufactured, installed and serviced.

The range earned its name because of its performance.

Symphony drives produce a clean sine wave with low harmonic content, enabling smooth interaction with the motor.

Such a harmonious composition resulted in the 'Symphony' name.

This new air-cooled drive can cover the power rating 500-3000HP and is suitable for controlling the speed of motors in applications such as industrial and municipal pumps, fans, compressors, blowers and mixers.

The dynamic performance of the drive also makes it capable of meeting the higher performance demanded by rolling mills, mine-winders and long conveyors.

Symphony drives are voltage source inverters based on pulse width modulated (PWM) multi-level topology which is the key to the drives.

Patented in 1995, the design is solely licensed to Alstom who has modified, improved and applied the latest technical advances to an already proven product to develop the air-cooled version with several benefits to the user.

Highly efficient and reliable, Alstom's latest drive provides low operating costs and is easy to use, featuring advanced controller features.

The controller has comprehensive built-in tests and diagnostics with on-line help to ensure maximum protection and detection of problems as they develop, not just once they have occurred.

The controller has sufficient capacity that the majority of external functions can be accommodated with no additional PLCs.

With a minimal component count and modular construction, the Symphony is low on maintenance time and costs.

The reduced number of power switching devices and minimal filtering requirements enable Symphony to achieve a very high converter efficiency, greater than 98%, and a typical overall drive efficiency, including input transformer, of greater than 96.5%.

Symphony uses the latest type of medium voltage IGBT, which is the optimum switching device for the multi-level topology in this power range.

IGBTs permit a higher pulse width modulation (PWM) frequency to be employed, which reduces motor ripple current and torque pulsations, and increases dynamic performance.

This also allows faster response under fault conditions, providing better protection.

In addition to being user-friendly, efficient and having low maintenance requirements, Alstom's Symphony drive offers maximum dynamic performance with minimum losses, is IEE 519 compliant and meets the latest EMC requirements.