Specialist electrical equipment for particular markets

REO UK, a specialist in high-quality power equipment such as electronic controllers, components and electrical regulators, is fully capable of providing products to meet the specific needs of particular markets or industries. One example of this is a range of purpose-wound components that the company has recently created for the railway industry.

The products are from the Nieke division of REO Inductive components, which has had over 50 years experience in designing and producing components for use with AC and DC converters employed in the railway industry, where reliability is a priority. There are three broad categories of components: chokes, transformers and inductor/filters.

For DC traction systems the company has developed harmonic filters, short-circuit current limiters, chopper reactors and line filters with designs that ensure good linearity of inductance with varying current and frequency. Often DC chokes are fitted to provide protection against short-circuits but they also filter out parasitic AC disturbances.

One particular choke, which is used for resonant filters on 15kV mains transformers that are fitted to European locomotives, has a novel air-core design that is free of stray fields. Consequently it is highly stable, irrespective of frequency, and has low losses even at very high frequencies.

Another important application for chokes is for limiting the dV/dt between the converter and motor with the purpose of extending motor life, reducing audible noise and providing current smoothing. Other chokes are produced for reducing harmonics and for providing smoothing on auxiliary converters, which provide power for buffet cars, air-conditioning equipment and passengers' laptop computers.