A clear trend towards local rail transport

The future, both nationally and internationally, belongs to electrified rail transport – and, above all, to electric public transport in urban areas. Owing to the increasing impact of densely populated urban centres, and the emergence of ever more megacities, it is no longer possible to imagine getting around without high performance rail transport. In view of the trend towards continuing urbanisation, underground trains and trams are seeing phenomenal growth worldwide as a low-cost, reliable mode of transport.

Climate-friendly transport of the future

Faced with the important goal of keeping the air clean, rail transport – as a climate-friendly transport system – has additional significance. The EU Commission has stated its aim to reduce greenhouse gas emissions in the transport sector by 20 per cent by 2030, against a 2008 baseline. Rail transport will play a key role here, as emphasised by a glance at the German transport sector: whereas road traffic is responsible for less than a fifth of greenhouse gas emissions, rail transport contributes under one per cent of the total.

Focus on optimum reliability

Power systems are a fundamental part of our daily lives that usually go unnoticed. The systems that power underground trains or trams in local public transport networks generally only come to our attention when they fail during service and leave passengers trapped in a stationary underground train, for instance. The reliability of drive systems during continuous operation is therefore top priority.

Power semiconductors drive the train

Power semiconductors are the main components in a power converter that transforms current, voltage and frequency. Power converters control the output of traction drives for electric mainline and urban trains and supply energy to the auxiliary units of rail vehicles, e.g. the lighting, ventilation and air conditioning.

Intelligent SKiiP4 IGBT phase module 1700V/3600A with integrated water cooler

Demanding requirements on power electronics

The operating conditions in traction applications place demanding requirements on the power converter and power semiconductors in terms of power and temperature cycles and ambient temperature. Additional demands placed on power electronics include compact overall dimensions of the systems, high power density and good vibration and shock resistance.