The Anonymous Widower

More On Batteries On Class 802 Trains

In the December 2021 Edition of Modern Railways, there’s an article called Battery Trial For TPE ‘802’.

Class 802 trains are now involved in two battery trials.

• One involves Great Western Railway (GWR) trains, which I wrote about in Hitachi And Eversholt Rail To Develop GWR Intercity Battery Hybrid Train – Offering Fuel Savings Of More Than 20%.
• A second involves TransPennine Express (TPE), which I wrote about in Hitachi Rail And Angel Trains To Create Intercity Battery Hybrid Train On TransPennine Express.

This article puts some flesh of the bones of the two trials.

It is hoped that replacing one diesel engine (generator unit) with a battery pack will enable the following.

• Reduction of carbon emissions by at least 20 %.
• Reduction of fuel consumption.
• The ability to rely on battery power when entering and leaving stations to reduce noise pollution and emissions.

This paragraph explains a possible way the trains will be operated.

Another option is to use the battery to provide ‘classic’ hybridisation efficiency, allowing most diesel running to be done fuel-efficiently under two engines rather than three. In this case, the battery module would provide top-up power for peak demand and give regenerative braking capability when operating in diesel mode, which the trains currently do not have.

This is one of the aims of the GWR trial and I suspect anybody, who has owned and/or driven a hybrid car will understand Hitachi’s thinking.

The next paragraph is very revealing.

To fully test the 6m-long, 2.2m-wide battery module, the intention is for it to be flexibly programmable in order for different approaches to charging, including from the overhead line power supply, diesel engines and during braking , to be evaluated.

It looks to me that Hyperdrive Innovation will earn their fees for the battery design and manufacture.

This picture shows the underneath of a Class 802 train.

Note.

• The car is 26 metres long
• The car is 2.75 metres wide.
• The MTU 12V 1600 diesel engines, fitted to a Class 802 train, each weigh around two tonnes.
• The engines have a power output of 700 kW

I would think that the 6 x 2.2 m battery would fit under the car easily.

As an engineer, who has evaluated all sorts of weight and balance problems, I would make the battery similar in weight to the diesel engine. This would mean that the existing mountings for the diesel engine  should be able to support the battery pack. It would also probably mean that the handling of a car with a diesel engine and one with a battery pack should be nearer to being identical.

Tesla claim an energy density of 250 Wh/Kg for their batteries, which would mean a battery with the weight of one of the diesel engines could have a capacity of around 500 kWh.

As a Control Engineer, I believe that Hitachi and Hyperdrive Innovation have a tricky problem to get the algorithm right, so that the trains perform equally well under all conditions. But with a good simulation and lots of physical testing, getting the algorithm right is very much a solvable problem.

The article says this about the reliability of the diesel engines or generator units (GU) as Hitachi call them.

Whilst reliability of the generator units (GU) has improved, operators of the bi-mode sets still report frequent issues  which see sets ending their daily diagram with one out of use.

I wonder, if battery packs will improve reliability.

From statements in the article, it looks like Hitachi, MTU and the train operating companies are being cautious.

The article also says this about the design of the battery packs.

The battery pack has been designed so it is a like-for-like replacement for a GU, which can maintain or improve performance, without compromising on seats or capacity.

I have always said it would be plug-and-play and this would appear to confirm it.

How Will The Batteries Be Charged?

I showed this paragraph earlier.

To fully test the 6m-long, 2.2m-wide battery module, the intention is for it to be flexibly programmable in order for different approaches to charging, including from the overhead line power supply, diesel engines and during braking , to be evaluated.

GWR and TPE run their Class 802 trains to several stations without electrification. and they will probably need some method of charging the battery before leaving the station.

This is Hitachi’s infographic for the Hitachi Intercity Tri-Mode Battery Train.

Note.

1. This infographic was published with the Hitachi press release announcing the development of the tri-mode train for GWR.
2. One diesel engine has been replaced by a battery pack.
3. Charging the battery can be under wires or 10-15 minutes whilst static.
4. At some stations like Exeter St. Davids, Penzance, Plymouth or Swansea, heavily-laden services might need the assistance of batteries to get up to operating speed.

The infographic released with the Hitachi press release announcing the trials for TPE.

It is similar, but it says nothing about charging.

So how will these trains be charged in stations like Hull, Middlesbrough. Penzance, Scarborough and Swansea, so they leave on their return journey with a full battery?

Consider.

• The formation of a five-car Class 802 train is DPTS-MS-MS-MC-DPTF.
• Pantographs appear to be on both driver cars.
• The middle three cars have diesel engines.
• Only the middle three cars have traction motors.
• There is probably a high-capacity electrical bus running the length of the train, to enable electricity to power all the cars from either or both paragraphs, when running on an electrified line.

The simplest way to charge the batteries would probably be to install a short lengthy of 25 KVAC overhead electrification in the station and then to charge the batteries the driver would just raise the pantograph and energise the electrical bus, which would then feed electricity to the batteries.

I wrote about Furrer + Frey’s Voltap charging system in Battery Train Fast Charging Station Tested. This charging system would surely work with Hitachi’s designs as batteries can be charged from overhead electrification.

Conclusion

I suspect that Hitachi will achieve their objectives of saving fuel and cutting emissions.

But there is more than this project to just replacing one diesel engine with a battery pack  and seeing what the savings are.

It appears that the battery packs could have an effect on train reliability.

If the battery packs are truly like-for-like with the diesel engines, then what will be effect of replacing two and three diesel engines in a five-car Class 802 train with battery packs.

Will it be possible to develop an ability to setup the train according to the route? It’s only similar to the way Mercedes probably set up Lewis Hamilton’s car for each circuit.

But then the speed Formula One cars lap Silverstone is not that different to the maximum speed of a Hitachi Class 802 train.

November 26, 2021 - Posted by AnonW | Transport/Travel | Class 802 Train, Control Engineering, Diesel/Electric/Battery Hybrid Trains, Furrer + Frey, Great Western Railway, Hitachi, Hitachi Intercity Battery Hybrid Train, Hitachi Intercity Tri-Mode Battery Train, Hyperdrive Innovation, TransPennine Express, Voltap Charger