Bombardier-Rolls-Royce joint venture for hybrid train

[tomuk]

I'd be interested on what size battery there proposing. I would think it would need to me able to provide full power for 90sec or so needed to get up to say 60mph. Volvo buses do just 12secomds on battery before the engine kicks in.
K

The battery pack is modular built up of 30.6 kwh battery packs. You can have up to 4 so a maximum of 122.4 kwh is possible if you can find room for the packs. The motor is rated at 200kw so presumambly you could get 18mins at full power off two packs.

 

[route:oxford]

The battery pack is modular built up of 30.6 kwh battery packs. You can have up to 4 so a maximum of 122.4 kwh is possible if you can find room for the packs. The motor is rated at 200kw so presumambly you could get 18mins at full power off two packs.

Don't batteries often have a peak and steady discharge rates though?

So two batteries may well be able to deliver 200kw or more for say the first 10-20 seconds, but after that the ongoing delivery is probably going to be about 150kw, that would mean around 23-25 minutes at 75% power.

So you'd probably need 3 for a 200kw motor which would give you 25-27 minutes at full power depending on the initial draw.

 

[gsnedders]

Don't batteries often have a peak and steady discharge rates though?

So two batteries may well be able to deliver 200kw or more for say the first 10-20 seconds, but after that the ongoing delivery is probably going to be about 150kw, that would mean around 23-25 minutes at 75% power.

So you'd probably need 3 for a 200kw motor which would give you 25-27 minutes at full power depending on the initial draw.

Roughly, yes.

Quoted capacity is normally based on sustained discharge over a 20 hour period at 20°C.

Discharge current and terminal voltage both effect the ability to deliver charge, and the relationship here depends on the battery chemistry, and I haven't seen anything saying what type of battery they're using. Most, IIRC, follow an inverse power law with as the current increases.

 

[superkev]

The battery pack is modular built up of 30.6 kwh battery packs. You can have up to 4 so a maximum of 122.4 kwh is possible if you can find room for the packs. The motor is rated at 200kw so presumambly you could get 18mins at full power off two packs.

You have to careful here as quoted battery capacities are based on discharge over several hours. Discharging in say the 2 minutes or so it takes a 170 to reach 60mph would have a significant impact on the battery size chosen even if it where possible. I'm sure someone here will be able to tell us what size battery would be required and how may tons it would weigh to match the 170 engine output of 422bhp for say one minute. I'm too old to be bothered and lead acid was king I'm my day.
Perhaps supercaps may be a better bet for trains.
K

 

[route:oxford]

You have to careful here as quoted battery capacities are based on discharge over several hours. Discharging in say the 2 minutes or so it takes a 170 to reach 60mph would have a significant impact on the battery size chosen even if it where possible. I'm sure someone here will be able to tell us what size battery would be required and how may tons it would weigh to match the 170 engine output of 422bhp for say one minute. I'm too old to be bothered and lead acid was king I'm my day.
Perhaps supervisor may be a better bet for trains.
K

422bhp is 315kw

A hydraulic gearbox is around 85% efficient, so that's 268kw. Probably why the 200kw is mentioned above once you take into consideration hotel services.

An off the shelf 30.6kwh lithium battery is capable of giving a peak output of 406kw for 10seconds. So, I'd expect that it would be able to deliver 50% (200kw) of it's capacity for say 25 seconds - not enough to cover a Class 170's 0-60 in 114 seconds.

But why mess around with peaks, when you could simply fit 4 30.6kwh batteries that would deliver a continuous 308kw? Perfect for a 200kw motor plus hotel services.

Each battery is 1,546mm x 750mm x 216mm and weighs 352Kg - so a total of 1408Kg. Probably about the right size to fit under each vestibule of a class 170. (If there isn't already stuff underneath it).

 

[superkev]

422bhp is 315kw

A hydraulic gearbox is around 85% efficient, so that's 268kw. Probably why the 200kw is mentioned above once you take into consideration hotel services.

An off the shelf 30.6kwh lithium battery is capable of giving a peak output of 406kw for 10seconds. So, I'd expect that it would be able to deliver 50% (200kw) of it's capacity for say 25 seconds - not enough to cover a Class 170's 0-60 in 114 seconds.

But why mess around with peaks, when you could simply fit 4 30.6kwh batteries that would deliver a continuous 308kw? Perfect for a 200kw motor plus hotel services.

Each battery is 1,546mm x 750mm x 216mm and weighs 352Kg - so a total of 1408Kg. Probably about the right size to fit under each vestibule of a class 170. (If there isn't already stuff underneath it).

Hmm 1408kg, around 1.5tons, of expensive 7 year life battery to hump around just to get the train moving. It would save a bit if juice though by storing braking energy. There's a lot of energy in that horrid diesel. Around 20kw in every gallon I seem to remember.
Im sure more electrification would be cheaper if Network rail got there act together particularly with all those surplus emu's around. Or, there's always supercaps to try.
K