Specification of static auxiliary converters for rolling stock

The auxiliary power supply system is one of the most crucial systems used in rolling stock. It provides power to every electrical system and equipment on a train including those that are critical to its safety and operability. A failure within the system would render the whole or part of the train nonoperational resulting in financial loss, operational problems to the railway and discomfort to passengers. At the heart of the system is the auxiliary power generator, in the form of static power converter in recent applications, which provides the required electrical supplies for AC auxiliary loads and battery charging. The ultimate suitability of any product depends to a substantial extent on the quality of the specification on which the product design is based. This is especially so within the highly specialised and environmentally demanding area of rolling stock. The author discusses some of the more critical information and design requirements that should be embodied in a specification for static auxiliary power converters for rolling stock to help the supplier achieve the basic requirements of the customer for safety, compactness, simplicity of design, reliability and ease of maintenance.