Ricardo’s rail industry experts look at the use of virtual reality for testing new hydrogen trains

5 min read

Virtual reality testing has the potential to bring to market new hydrogen-powered trains faster in the future, according to industry experts from Ricardo, which provides a wide range of rolling stock and infrastructure testing services for the rail sector.

Virtual vehicle dynamics testing using Simpack 2
Virtual vehicle dynamics testing using Simpack 2

In partnership with Scottish Power, Network Rail Scotland and the University of Leeds, the firm is also working on the Holistic Hydrogen Approach to Heavy Transport (H2H) project, which will pilot the use of green hydrogen to test prototype hydrogen-electric trains with the eventual aim of replacing diesel trains on rural routes in Scotland by 2035 (read more about this project in the latest issue of Electric & Hybrid Rail Technology).

EHRT spoke to Ricardo’s Ilse Vermeij, product manager of testing, and Joanna Richart, head of the firm’s hydrogen business, to find out more about the company’s use of virtual testing for electric train approval and for calculating energy consumption, and how pantograph simulations helped one firm save around €300,000 in testing costs.

How can virtual testing help bring to market hydrogen trains faster in the future? 

Vermeij: There are three main ways I think simulation and virtual testing can deliver hydrogen trains into service faster.

The first is for railway owners. With a strategic viewpoint they can assess the most effective traction option for their routes/networks without relying on expensive and time-consuming pilot programs. With several alternative fuel options and bi- and tri-mode vehicles adding to the complexity – optioneering (assessing the effect of different solutions) virtually, together with strategic scenario planning are increasingly important to assess efficient routes to achieve decarbonization goals. We have worked in both the UK and the Netherlands to inform their traction power strategies.

The second is in my area of expertise in vehicle testing and approval. Most of the testing of new hydrogen trains will not be related to the hydrogen propulsion system itself. When a manufacturer builds a hydrogen train based upon existing vehicle designs, the possibility arises to avoid some of the on-track tests. For instance, the typically time-consuming running dynamic tests can be performed virtually. Using validated models of existing conventional designs, the effects of the update to hydrogen on vehicle characteristics can be modelled virtually minimizing physical development and testing requirements and accelerating approvals.

The third is in (virtual) testing of the powertrain itself. Ricardo has over 100 years’ experience in optimizing powertrains, with extensive battery, fuel cell and hydrogen engine test and development facilities. Physical powertrain testing is supplemented with virtual testing such as hardware-in-loop together with virtual simulation capabilities to speed up product development cycles.

Has Ricardo used virtual testing for hydrogen powertrain testing to date?

Richart: Due to commercial sensitivity, most of our powertrain development work is covered by non-disclosure agreements. However, our extensive experience with simulation and modelling of conventional engines, battery and fuel cell vehicles in automotive and heavy-duty vehicles is obviously directly applicable to the rail area. As the rail sectors acceptance and adoption of alternative powertrains advances, it is wise to take advantage of the lessons already learned in the automotive and heavy-duty vehicles sectors.

Ricardo is currently commissioning new fuel cell and hydrogen engine test equipment to supplement the existing center of excellence powertrain test facilities. The new test facilities feature specialist purge and extraction ventilation, gas detection, and the latest safety features, together with hydrogen pressure and consumption measurement. The fuel cell chamber also features ambient temperature control up to 90°C. The test cells can be connected to our virtual battery simulation units, allowing system and subsystem testing combining the capabilities of both real-life and virtual testing together.

What virtual testing is being carried out on electric trains? 

Vermeij: For electrical trains one of the most critical aspects for approvals is what is called “production of interference currents” sometimes known as Electro-Magnetic Compatibility (EMC). Because trains are connected to the overhead line (via a pantograph) it is possible that they influence the train protection (signaling) system, leading to failures and unexpected behaviors. When designing the traction installation, manufacturers perform simulations/virtual testing of the expected interference currents. Final approvals are granted based on physical tests, which I don’t see changing soon. However, as confidence in models and virtual testing grows, I can see a potential reduction in the scope of physical tests reducing both cost and risks for manufacturers.

Another form of virtual testing we’ve carried out recently is calculating energy consumption and energy recuperation to predict and analyze operational vehicle behaviors without performing extensive in-service measurements.

Tell us more about a recent virtual testing project you have worked on? 

Vermeij: Recent virtual testing project examples are an anti-icing catenary project for RSSB and the development of hydrodynamic bogie bushes for NS.

The anti-icing project used RiPAC OCL-pantograph simulation software to investigate the effect of different loads of ice as well as anti-icing, and de-icing measures, on the contact quality of the pantograph against the contact wire. Without the use of simulation this sort of evaluation is practically impossible to perform with physical testing, where control of environmental variables is usually impractical.

We used Simpack for the development of a hydrodynamic bush for vehicle bogies. We optimized the hydrodynamic bushing performance and provided a new report according EN14363:2016 for certification of the new running dynamics. Using virtual testing avoided both the time and €300,000 cost for a physical test campaign.

Will testing and certification ever be fully virtual?

Vermeij: No, that is not what I expect, this would require huge investments. I am not even sure if it will be technically possible in the foreseeable future. Virtual testing should be a tool to help the industry to make smarter design choices early in the process, to reduce risk and to reduce the scope of physical on track testing required. We should focus on the low hanging fruit first, the higher up you get in the tree, the more difficult and expensive it becomes.

What are the overall benefits of virtual testing? 

Vermeij: Virtual testing reduces risk and reduces cost. No one wants to be in the situation where problems are picked up during approval testing. Virtual testing offers the potential to pick up problems early or to test new ideas before committing them to physical production.

When a manufacturer delivers vehicles that are largely based on already approved vehicles using the same platform, then virtual testing becomes very interesting and even more attractive. You can use the existing approved vehicles for model validation, making it much easier to accept virtual testing results for certification and approvals.

How else is Ricardo testing hydrogen powertrains? 

Richart: We are working on both hydrogen engine and hydrogen fuel cell work for various OEM clients and have project spanning land, sea and even air!

On land we have recently been showcasing our hydrogen retrofit expertise in the bus sector with Stagecoach. By converting an existing diesel vehicle to operate on hydrogen a saving of 45-90,000kg of CO2 can be achieved even with current CO2 content in hydrogen mix. The amount of saving is dependent on the age of the bus at time of retrofit and the route of the bus.

In the air we are working to retrofit hydrogen propulsion to a nine-seat airplane demonstrator in a project called Fresson. The power output demand and strict weight restrictions mean Ricardo must design a bespoke multi-stack fuel cell solution that will be tested in our Shoreham facility

At sea we continue to see a large demand for decarbonization. After the HIMET project, where Ricardo modified a natural gas engine to run on hydrogen, we have secured further commercial projects for much larger vessels. The engine from HIMET project is available to support clients testing of new lubricants or after treatment options to address need of the growing hydrogen sector.

There is a large a variety of hydrogen projects keeping our recent multi-million investment in hydrogen testing and development facilities busy, although we of course welcome enquiries for more work for our experts too.

Is there anything else you would like to add?

Richart: It’s very exciting to see the global demand for hydrogen powered vehicles growing, driving demand for hydrogen. Industry is moving to larger scales, which will bring its own challenges. Many suppliers of fuels cells and electrolyzers are not familiar with mass manufacture. Ricardo performance product teams are helping many companies to design for manufacturing and assembly, and to introduce the robust manufacturing process and quality controls needed to succeed in this rapid upscaling challenge.