It is vital that train manufacturers today keep trains operating with minimal disruption and downtime. With more passengers relying on train services than ever before, it is crucial that engineers have access to the components they need quickly to undergo repair and maintenance work. Paul Bentley, managing director of GD Rectifiers explains how power electronic components are helping keep the UK’s infrastructure running seamlessly.
The railway industry is undergoing rapid changes in the quest for energy efficiency, increase of economies, reliability, effectiveness and quality of railway transport. Today’s railroads evolve in to an ever more high-tech industry, with the aim to reduce commute time and the UK’s global footprint.
Whether it is rolling stock, services, system and signalling, including railway related telecommunication equipment or infrastructure, many challenges are being faced throughout the market and manufacturers are under immense pressure to provide high quality, reliable and sustainable designs.
When a train is manufactured, numerous rigorous steps are required before launch, this includes research and studies, full-scale design models and aerodynamic tests, manufacturing train components, traction chain tests, testing elements for crash simulation and fabricating and testing the structure. Followed by the interior/fascia details such as painting, window and floor installation, cable assembly, installing interior equipment, electrical tests, placing the body on to the bogie, train assembly, loading the on-board software, static tests, followed by dynamic tests in the factory and customer’s lines.
When customers think of rail engineering and manufacturing, they think of the big systems such as traction converters, PEBBs, liquid cooling systems, auxiliary drives, power supplies and rolling stock. One of the most unknown and underrated elements to providing reliable train systems today is the power electronic components used to repair and prolong the life of the systems. Train manufacturers and OEMs rely heavily on an extensive range of passive electronic components, including: IGBTs, MOSFETs, thyristors, diodes, resistors, capacitors, high voltage rectifiers, fuses, heatsinks and rectifiers.
Today, railway manufacturers and contractors are seeking further efficiency savings in the full range of electrical components that meet low life-cycle costs. Passive components, including rectifiers, high voltage diodes, heatsinks, filters and capacitors enable increased productivity and capabilities. This improves operational availability and control of on-going maintenance costs which is a colossal priority for engineers.
One of the biggest challenges the railway industry faces when sourcing power electronic components is obsolescence. Components have to undertake rigorous testing in order to be an approved component for manufacturers and this process costs engineers a lot of time and money.
With power electronic component OEMs issuing end-of-life notices more rapidly year-on-year than ever before, engineers are put under increasing pressure to either source a last time buy (knowing that they’ll need to replace the component in the future), use superior components that are mechanically and electrically interchangeable from the same manufacturer, or to source a completely new component and start the rigorous testing process again. The engineer’s decision will be impacted by how quickly they need the component and how severe the maintenance issue is.
The following electronic components, devices and systems are commonly used throughout the modern rail industry, contributing to technological innovation and providing custom solutions to suit the ever-changing demands of rail engineering:
- IGBTs are used across a wide range of railway traction technologies
- MOSFETs provide auxiliary power supplies in the railway sector
- Thyristors GTOs are designed for railway traction
- Fuses are used in main and signaling circuits at railway stations
- High voltage diodes are usually used in overhead signalling lines and on tracks
- Heatsinks are used to provide LED lighting on the platforms
- Capacitors are used to track the presence of the trains on the rail tracks
- Rectifiers are used for railway DC traction
- Resistors are used across trams, metro, light rail and high-speed trains, they all need resistors for different kinds of applications
- Trackside converters are fed with energy from overhead line, they supply various loads in substations, including power supply for integrated lighting and information systems, railway signalling and protection systems
- Converters for coaches offer high quality and reliability that significantly increase traffic availability of passenger coaches
- Converters for trains convert voltage from generators in to the drive power for the traction motors, three-phase auxiliary power supply for the train on-board consumers and into DC auxiliary power supply for charging train batteries
- Converters for trams supply the main and auxiliary drives of trams
- Converters for locomotives are used for supplying the main and auxiliary drives for locomotives
- Liquid cooling systems are designed for installation in the traction converter, the liquid cooling system uses water to cool the converter power modules
- Power electronic building blocks are subsystems for traction converters, they are liquid cooled building blocks designed for propulsion converters in traction applications.
The wide spectrum of track and traffic conditions found in the railway environment heavily rely on electronic components, devices and systems to keep the rail industry operational. Today, engineers need to work with OEMs and distributors as their supply chain partners to secure the stock quickly, ensuring minimal downtime of system failures.
Electrical and mechanical components for the railway industry must provide safe and reliable operations even under extreme application conditions. Engineers need to focus on the most effective ways to revolutionise the industry by using components that will deliver longer in-service product life, increased safety, reducing maintenance, energy consumption and renewal costs for customers.