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EV

DMiller

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Problem with motors is they tend to be All On instead of throttled even when voltage or amperage is slowly applied. Seen a good many Locos lightly throttle up the Prime Mover and get drive wheel slip/spin almost instantly.
 

Delmer

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And if you remember my posts earlier, electric motors in my application will have tons more power. I would bet a 200 HP motor would pull the same or better than a 400 diesel.

Depends. If you hook up to the grid and have a 200HP electric motor on a load compared to a 400HP diesel engine, then yes, the 200HP electric will probably have better starting torque, better torque over most of the range, and might be able to match the peak "surge load". I doubt a 200HP electric motor will last very long at 350 HP, maybe a B Cummins won't last long at 350HP either? but a bigger diesel would run at 7/8 load just fine. I know if you swapped a 3 HP electric motor in place of an 8 HP gas engine, in most cases the electric will handle the load much easier, but there's more overcapacity built into smaller motors as far as I can tell.

But you're not talking about hooking to the grid, you won't magically get better performance because it's electrified. It would take quite a battery pack (not to mention a ton of engineering) to get a generator driving an electric motor to match the performance of an automatic transmission. If the other components would benefit from VFD, then that part could make a lot of sense. If the air compressor is anything significant, I'd run it off the front of the generator engine. I've never seen a diesel electric air compressor, for good reason.
 

cfherrman

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I won't be running the motors over their HP rating, there is plenty of b Cummins Genset at that HP, or even the c 8.3 if needed, still better than a 14l

Generator driving electric motors is not new, vfd is not new, this is rather easy, all the components are in common use. Money and time is limiting for me and currently I'm out of work due to health reasons so I am even father behind.
 

92U 3406

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Dunno if this has been posted but:

https://www.teck.com/news/news-rele...rt-truck-at-highland-valley-copper-operations

Pretty sure that truck in the picture is NOT the one on the route. Its a standard road tractor they're using.

To gross that weight legally you'd need a super b. The 25,000 kg/55,000 lbs tare weight stated seems awfully high for a daycab tractor and a super b side dump. I would think that setup should tare in at around 42-45k lbs with a regular, diesel powered daycab.
 

skyking1

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this is what I think of when I think EV. I followed along while he was building and playing with the white zombie, a drag racing Datsun 1200 with the zilla controller. It was before Tesla made it civilized.
https://i.postimg.cc/25tHJMWf/PXL-20220918-142554539.jpg
Back when they made little convertible metros with lead acid packs that could go ~40 miles, little home cooked rigs, neat cars like this 914.
 

cfherrman

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Manual transmission drive line is 98% efficient.
Alternator with wheel motors is 93% efficient.

Been meaning to comment on this as it's misleading or incorrectly compared. Trying to get more context.

Engine power to the wheels in a truck is probably less than 85% efficient.

Is the wheel motor being 93% efficient power at the wheel because that is awesome or is that just the efficiency of the motor?

Irc regular electric motors are 80-96% efficient, not sure how efficient a Generator is, but it would definitely have to be bigger than the motor
 

digger doug

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Been meaning to comment on this as it's misleading or incorrectly compared. Trying to get more context.

Engine power to the wheels in a truck is probably less than 85% efficient.

Is the wheel motor being 93% efficient power at the wheel because that is awesome or is that just the efficiency of the motor?

Irc regular electric motors are 80-96% efficient, not sure how efficient a Generator is, but it would definitely have to be bigger than the motor
These figures where taught to me in night school by an engineer well versed in the various drive systems. It's not my job to convince you otherwise.
 

Delmer

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The only problem is telling where the junk is. The 80-96% efficiency number for electric motors would be for a certain size level and near full load, that is, a "high efficiency" three phase motor above 5HP and running 80% load would typically be in that efficiency range. At 50% load the efficiency would drop, and at 10% load the efficiency would drop even further. A VFD does not make any motor more efficient, it makes the drive system more efficient that most of the alternative systems of slowing speed.
 

terex herder

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Going to Catenary systems as the Milwaukee Road once used would be simplest, Engines are already 600vAC so a line transformer system to that for distance hauls would be a fairly rapid swap where Diesels can still be used or converted to a Hybrid as some East Coast engines already are.

The abandoned Black Mesa & Lake Powell railroad used a 50,000V catenary line to power the locomotives that hauled coal to the power plant. Line was abandoned in 2019, and the power plant went dark shortly thereafter.
 

John C.

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Which died first, the railroad line or the coal fired power plant that powered it?
 

terex herder

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They were part of the same system. The railroad was private and existed only to service the power plant. The power plant lived for another 6? months to use up the coal inventory.
 

terex herder

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A 200 hp electric motor will put out 200 hp on a 100% duty cycle basis. A heavy duty diesel like a 3406 or 855 will also put out rated horsepower on a 100% duty cycle for a 10,000 hour life. Sure, that 12V cummins in your pickup will put out 600+ HP, until it melts down in less than 15 minutes.

The old saw about an electric motor being able to replace a gas engine twice or three times its rated power is true for single cylinder engines. Its not so much about power, but constant load vs cyclic power. The electric motor delivers multiple power cycles per revolution, depending of number of poles and motor speed. The 4 cycle gas engine delivers 120 % of rated power over about 120 degrees of crank rotation, and reabsorbs 20 % of rated power over the next 600 degrees of crank rotation.
 

Delmer

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It also has to do with starting and operating torque in some applications. Mostly, a gas engine will have to be oversized to have enough torque to get through the tough spots, so a third of the HP in electric will often work, even with a four cylinder gas engine. That mostly applies to under 40HP or so, and especially if replacing high reving gas engines. There were plenty of gas engines back in the day that were built for high duty cycle. Cummins and Cat still make spark ignition versions also.

One of the common electric conversions is an Allis G cultivating tractor, a small four cylinder gas engine is replaced with 2HP electric and it works better than the old worn out and poor running engine.

My understanding is the higher the electric motor HP, the lower the service factor and overload capacity. A 5HP electric motor can be overloaded 50% or more in the winter for hours with no problem, or easily for ten minutes in higher temps. A 200HP will let out the smoke much quicker with similar overload.
 
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