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Author Topic: First Group on the ECML  (Read 8117 times)
stuving
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« Reply #30 on: January 12, 2021, 06:24:42 pm »

Remember that the single generator unit (GU) on an 801 was there because of the requirement for hotel power to continue without a main electricity supply. The ability to move about a bit was secondary.

The electrical system components of an 800/801 are (AIUI) a pantograph/transformer/converter producing 3000 VDC, and a diesel engine/alternator/converter (GU) also producing 3000 VDC, as sources, and then the drive/converter feeding four motors, and an auxiliary power supply (APS) including battery charging, fed off the 3000 VDC. So adding one GU to an electric 800 covers the off-mains requirement without designing any new bits, and the capability of using some of its power in the motors comes almost with no extra work - though not quite "only software".

If you want to design a battery to do the same thing it would have to feed and give back power at 3000 VDC. I'm sure that's quite possible, but whether you would do it would depend on what you started from, and beefing up the existing 110 V battery might be a lot easier. The APS supplies the heaver hotel loads at 400 V 3 phase, which will cover the lighter single-phase 230 V ones as well. So I can imagine that uprating that would be a much easier option.

Of course they are also working on batteries for storing traction power too, but the recent (last month!) announcement of this was of an experimental unit (for GWR), and the agreement with Hyperdrive (last July) was to develop batteries. So it doesn't sound like they have one sitting on a shelf suitable for a production order.
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TonyK
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« Reply #31 on: January 12, 2021, 07:57:54 pm »

Of course they are also working on batteries for storing traction power too, but the recent (last month!) announcement of this was of an experimental unit (for GWR), and the agreement with Hyperdrive (last July) was to develop batteries. So it doesn't sound like they have one sitting on a shelf suitable for a production order.

At the time of the recent announcement, I tried to picture what type of battery would be needed to get a fully laden IET moving away from a platform without some sort of meltdown. My inner cynic, seldom far from the surface, thought the idea was a bit of a publicity stunt to stop people asking when the first electric train would arrive in Penzance. Presumably, the general idea is to use the batteries to keep moving once the diesels have helped the train to its top speed. I wonder if it is worth GWR's while, although I suppose it might cost nothing to let a private company develop something that they may or may not use.
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stuving
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« Reply #32 on: January 12, 2021, 08:29:40 pm »

Of course they are also working on batteries for storing traction power too, but the recent (last month!) announcement of this was of an experimental unit (for GWR), and the agreement with Hyperdrive (last July) was to develop batteries. So it doesn't sound like they have one sitting on a shelf suitable for a production order.

At the time of the recent announcement, I tried to picture what type of battery would be needed to get a fully laden IET moving away from a platform without some sort of meltdown. My inner cynic, seldom far from the surface, thought the idea was a bit of a publicity stunt to stop people asking when the first electric train would arrive in Penzance. Presumably, the general idea is to use the batteries to keep moving once the diesels have helped the train to its top speed. I wonder if it is worth GWR's while, although I suppose it might cost nothing to let a private company develop something that they may or may not use.

There's another thread for that you know! But that initial trial train is a hybrid, so the battery has to be there to add extra power when the GUs are running flat out. That happens getting from mid-speed to fast quickly; the power needed at low speed is quite low. It has to be since it is (by definition, at the rail) equal to speed times force and the force (TE) is limited by adhesion to the same value (roughly) at all speeds.

But a supercapacitor would probably help!
« Last Edit: January 12, 2021, 11:05:14 pm by stuving » Logged
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