Featured Nissan e-power

http://www.autonews.com/article/20171114/OEM05/171119883/nissan-tests-versa-note-e-power-hybrid-for-u.s.

It appears that ePower could have a big plug-in battery, or simply be a standard hybrid with engine simply powering a generator that charges a battery or provides power to the electric motor(s) directly.

In this mode of constant rpm hooked to the load of a generator, and excess power charging the battery there is no need for variable valve timing or any egr, let alone cooled egr. I would build a cheap as possible engine, with thin walls (its low rpm so it doesn't need strength) valved for the most efficient atkinson cycle (probably around 40% thermal efficiency with drops in generation to motor or charging the battery). My guess is the engine is very inexpensive and provides around 35 hp. This would likely be fine for city mpg, but the prius hsd though more expensive would be more efficient at higher speeds. Having a bigger battery and a plug though would make it more efficient on the highway than the prius.

 

Asides this new innovation in the note, what happens at highway speeds with a lot of cargo loads in the rear, and all that, considering the engine only charges the battery pack, in order to discharge at the electric motors powering the wheels.

The engine is just a 1.2L one.

I don't think this car would be reliable during such long distance trios, except maybe advantageous in the cities.

My quess is that this would only work, if those electric motors have huge kWh in them.


Dxta

 

How simple is that?
HSD - 1 ICE, 2 MG
E-Power - 1 ICE, one Motor, one generator, one starter

 

I'm facepalming at the TTAC article's comments.

The Note E-Power has a 58 kW/78 hp engine (at 5400 RPM), and the traction motor produces 80 kW/108 hp. It'll spin that engine up if you need it:

Seeing how you're only getting about 22 kW from the battery, due to its size, you do need a fair amount of engine power to make up the difference.

Charging and discharging the battery at the same time is something that's completely nonsensical, and it doesn't actually happen. (It's just that it'll supply power to the traction motor alongside the battery, or the battery may take power from the generator.)

For long distance trips, the 1.2 should be fine, even if it's not ideal - it's making more power than the 1.5 in the (very much competing) Toyota Aqua/Prius c, and there's plenty of smaller engines asked to do a lot more in forced induction applications. However, that's not what this car has been optimized for - it's optimized for Japanese road conditions, which involve strict 100 km/h/62 mph speed limits, and lots of much slower city operation.

I don't see a starter motor in any of the overview images of the powertrain, and it wouldn't need one - the generator could be used as one. So, this system is simpler in terms of design and number of components than Toyota's hybrid powertrains - the generator and traction motor have to be bigger, as does the inverter assembly, but there's no actual power split gear set, and the control laws can be simpler (no need to worry about MG1 overrevving, as its speed is directly related to engine speed, without the MG2 speed component).

Efficiency is reduced from two (maybe three) factors - more losses due to the purely serial hybrid system, and the engine is a conventional Otto-cycle engine AFAIK. (The third possible factor is aerodynamics - AFAIK the Note is taller and probably higher Cd than the Aqua/Prius c.)

 

Dang! That thing is actually pretty fast. Holy smokes!

 

About 9 seconds to 100 km/h it looks like, that's considered slow by modern American standards, but it's faster than any stock Prius...

 

Constant rpm makes it less expensive to make efficiently. This was the original idea of the generator for the ev-1 serial phev. Agree completely that variable rpm doesn't cost much more, but then you will likely need variable valve timing on the intake valves to stay efficient, and a slightly more expensive generator that is efficient. Probably the least expensive efficient rpm range is 1500-4500 which will probably provide about 2.5x range of power at peak efficiency.

Do you have throttling losses in a serial phev (or hybrid) when excess power from the generator charges the battery, and the ice is kept cool by not operating outside a range. In a constant rpm/constant power application this will probably gives something like a valve timing and compression to give a 12:1 compression stroke/ 14:1 expansion stroke and stoich fuel mix + slight enrichment for the cat to work. There aren't throttling losses, in fact the ice/generator combination doesn't even react to the throttle, only the battery level. Make it variable rpm, but still loaded by a generator or psd with variable late intake valve closing, and the ice will react to the throttle, but it can be kept at a full generator load to charge the battery with no throttling losses. Higher rpms will likely have a smaller range of compression strokes (late intake valve closing) to stay in efficient and low polluting without egr. The engine may run so cool that variable lift on exhaust valves and/or catalytic converter electronic warm up is required for proper operation of the catalytic converter.

The 0.65 liter bmw rex produces 38hp@4800 rpm with on premium fuel. BMW also specifies it gets 25kw or 34hp at its torque peak of 4300 rpm, which is probably where it limits the rex for most duty. All things being equal a 1.2l 3cyl will be more efficient and have better nvh at 2500 rpm than a 0.65 2 cyl at 4300 rpm especially if they are producing the same power and driving a well specified generator. The prius engine alone ways about 220lbs, the rex addition with fluids, mounts, tanks, and pollution control weighs 270lbs. My guess is a 1.2l 3cylinder generator plus all accompanying additions will add about 325 lbs to a bev or about as much as 30 kwh of hours of batteries. My guess is if you limited it to 1500-4500 rpms and based it off an existing 3 cylinder design, it would not cost anymore per unit than the bmw low run engine. Nissan produced a tiny (88lb -500 mm tall x 400 mm long x 200 mm wide), 1.5l 3 cylinder engine producing 400 hp for f1 experimental car. The bmw rex addition adds less than $4000 to the cost of a car, and I bet nissan could do it for less ;-) If you limit such an engine to 4500 hp and create a stroke for 14:1 expansion but have to limit compression to about 10.5:1 at high rpms to stay cool and efficient, then it probably would produce a peak of 60hp, using nissan's existing engine. Nissan also has an existing version that is supercharged using miller cycle producing 97hp. Either would work better than the i3-rex is such an application, with the miller cycle variant being used when you need more power for the vehicle, but likely you would switch to a more efficient electrical supercharger from a mechanical one in a phev application. A more expensive more efficient engine might be made from the skyactiv-x with spark controlled compression ignition with a 1.2 liter producing about 120 hp peak, but lean burn allowing for much more efficient power under 40 hp.

 

Nissan e-Power explained, Australian launch a certainty

Interesting to see what the author believes Nissan will plop epower into.


And yeah, I did not believe TTAC deserved it’s own unique thread.

 

http://www.autonews.com/article/20180304/OEM06/180309763/nissan-epower-van-hybrid

More rumors, looks like Nissan only plans on epower being in upscale land barges here in the states.

I would have rather had an small inexpensive , efficient hybrid

Ah well, too bad so sad
Time will tell

 

it's amazing how few of these announcements come to fruition. must be good pr.

 

yea . . . . made me wonder .... is this an attempt by Nissan to keep land barges (albeit more efficent ones) in the game?

 

To be entirely fair, it sounds like they're not aiming to add that much power. They're talking about matching their current 2.5 liter, which is making on the order of 170-180 hp (or about 125-135 kW).

One thing to keep in mind is that the fastest speed limits in Japan - and those are strictly enforced - are 100 km/h, or 62 mph. Everyone drives a lot slower.

So, a solution meant for never going faster than 100 km/h, and with gentle acceleration at that, will have trouble with European or American roads, where cruising speeds are often 130 km/h (81 mph) or faster, with hard acceleration to get merged.

If they're going to put this in something like an Altima or a Rogue (which are common classes in the US), targeting 170-180 hp is about right.

 

More tidbits on the epower

https://www.google.com/amp/s/insideevs.com/nissan-teams-with-ceres-for-future-fuel-cell-tech-for-evs/amp/

But this time tied to the ebio fuel cell


Next our favorite shovel writer TTAC is mentioning Epower needs to beef up and Infinity before coming here in this brief undescript blurb

Before e-Power Makes It Here, Nissan First Has to Send It to the Gym - The Truth About Cars

The note still sells well in Japan at least

Nissan Note is Japan’s number one car during 2018 H1, updates unveiled | Between the Axles

And lastly epower 4wd

2019 Nissan Note e-POWER 4WD – Video | DPCcars

 

Nissan finished up a test program in Brazil using their fuel cell in a NV220e; their little work van with the Leaf's drive train(though it has a fan for cooling). There is a thread here about them freezing FCEV development, but this news means they are actually subcontracting it out.

The idea of making BEVs, but offering a range extender in the form of an ICE or fuel cell, is how I see future personal cars going.

 

Nissan Launches Punchier e-Powered Note Nismo S for Japan - The Truth About Cars

Yep looks like epower is in blackout mode,

See how many years it takes before epower actually comes over

All recent releases are about epower going into the India market place

 

do you think it would do much here?