InnoTrans 2018

•••20••• Innovationen How to make maintenance more effective New technology allow operators to continuously monitor the condition of systems and components M odern condition monitoring techniques can lead to bet- ter maintained, extra reliable and more comfortable rolling stock, meaning that more and more passengers will take the train. Experts at the University of Hud- dersfield are playing a central role in a project designed to transform the maintenance of rail vehicles – and they will test their new tech- niques on the trains operated by London Underground. The University is home to the In- stitute of Railway Research (IRR), where Dr Adam Bevan and Dr Xi- aocheng Ge are heading a con- tribution to an EU-funded Shift- 2Rail research programme titled “Smart Maintenance and the Rail Traveller Experience” (SMaRTE). The project focuses the use of information to enhance decision making and has two main themes: how to make rolling stock main- tenance more effective, and the human factors that persuade pas- sengers to choose rail travel. The University of Leeds takes charge of the latter element, while Hud- dersfield’s IRR handles the main- tenance and systems engineering dimension. The conventional approach to roll- ing stock maintenance is to carry out scheduled (interval-based) maintenance, which includes vis- ual inspection to check the con- dition of components. But new technologies are increasingly be- coming available and adopted which allow maintainers/opera- tors to continuously monitor the condition of systems and com- ponents. This technology can provide data to predict the on- set of problems, leading to early intervention and more effective rolling stock maintenance. Gains from this “smart maintenance” include cost savings and vehicle availability, due to the fact that rail vehicles spend less time out of service. This means that the capacity of the rail service can be increased and passenger satisfac- tion improved. The Institute’s researchers have reviewed existing maintenance strategies and condition monitor- ing techniques. They will develop new condition-based mainte- nance (CBM) techniques and pro- duce a prototype system that will be applied to vehicle systems and components using real data from specific train fleets operated by London Underground. The study results will be to identify the ben- efits of applying the CBM tech- niques compared to the current interval-based maintenance strat- egy and support the implementa- tion of the CBM-model by other train operators and maintainers. Maintenance of hard-working tube trains could be improved. Photo: University of Huddersfield Anzeige Power Converter Retrofit Solutions Amantys Power Electronics Ltd. • Hall15.1 Stand 213 Introduction Train operating companies re- quire their assets to have a long lifetime of at least 20 years. Du- ring the 20 year life of an elect- ronic component assembly, parts may wear out, suffer supply chain problems or become obsolete. Usually at the time spare parts are required, they are no longer available or become prohibitively expensive to source. Upgrading power converters is usually considered to be somet- hing that only the original equip- ment manufacturer (OEM) can undertake. However, Amantys Power Electronics Limited have collaborated successfully on se- veral projects to cost effectively upgrade the power converter with new gate drive, IGBTs, bus bars and heatsinks. The challenge After 15 to 20 years of service the challenge of sourcing replacement parts such as IGBT modules and gate drives can become a major problem for the maintenance de- partment and the train operating company, directly impacting the maintenance cost and the availabi- lity of trains for revenue generating service. The traction converter is an area re- quiring a high degree of knowledge and skill to maintain and upgrade. However, this is not necessarily a barrier to upgrading the power con- verter. The retrofit solution for the traction converter needs to work with some or all of the existing components. The practical implications of this are: • The stray inductance (Ls) in the converter can change; • A newer, faster switching IGBT module compared to the original, coupled with the stray inductance (Ls), may generate a large volta- ge overshoot that can damage the IGBT module; • The central controller may have a proprietary protocol to commu- nicate with gate drives; • The thermal management of the converter will need to work within the existing thermal envelope of the converter, i.e. result in no greater loss; The challenge therefore is to provi- de a solution that will work within these constraints and still provide a reliable and cost effective solution. The solution The first decision is to decide on the extent of the retrofit solution. This could be a replacement of the IGBT modules with new gate drives or be extended to include the bus bars, DC link capacitors and the heat sink. Amantys Power Electronics Li- mited has been working on gate drives that can be configured by the manufacturer or the end user. The configuration of the gate dri- ve is typically used to enable opti- mization of the electrical charac- teristics of the gate drive and the IGBT module to achieve the lowest switching losses in the target pow- er stack for the constraints of stray inductance and voltage overshoot allowable. In the case of a retrofit applicati- on the configurability of the gate drive can now be used to configu- re the gate drive to switch a mo- dern IGBT module with similar switching characteristics as the original IGBT module and gate drive. In the case of a more extensive retrofit the complete heatsink as- sembly can be replaced including the bus bars and the DC link ca- pacitors. Additional Benefits The inclusion of more modern components in the traction conver- ter also has additional benefits that may not be foreseen at the start of the project. For example, a feature of Amantys gate drives is that all of the faults that the gate drive sees during its lifetime are recorded on the gate drive. The maintenance department can view these faults at maintenance intervals so that the information could be used to track unusual operation, which may in some cases relate to the health of the converter. The ability to optimize the opera- tion of the IGBT module in the po- wer stack with more modern IGBT technology can result in a lower operational temperature of the he- atsink thus extending the lifetime. Conclusion Traction converters can be retro- fitted cost effectively, saving the train operator money when trying to source end of life or near obso- lete components. The retrofit solution can be repea- ted to keep track with new techno- logy trends. Amantys standard gate drive adapted for retrofit application Amantys Power Insight Configura- tion System