Auxiliary power supply systems for rail vehicles

An auxiliary power supply system is known 'in the trade' as an auxiliary converter. Developments in power electronic devices have allowed the design, manufacture and cost of auxiliary converters to be significantly reduced. Other advantages include reduced maintenance costs, reduced audible noise and less heavy equipment. All these factors are viewed by the rail industry as distinct advantages as they lead to cheaper, lighter and quieter equipment. A typical auxiliary converter and the factors affecting design are outlined. Developments in IGBT technology, and mechanical design of inverter modules are discussed.