Chevy Volt is 99% Ready

I think his point was that the Prius has both a parallel path and a series path. You could argue that it's not a parallel hybrid because of the series path, but that would be just as silly as saying it's not a series hybrid because of the parallel path. Neither distinction works because it is both.

I suppose you could say that it is a hybrid hybrid, being a hybrid of both the series and parallel designs. Toyota handled this conundrum by using the term "synergy" in the phrase "HSD", or Hybrid Synergy Drive.

Tom

 

Does 99% 'engineering ready' have any specific meaning outside of the minds of GM marketeers ? If something works, but works poorly, is it ready ? If the internal GM spec for ICE mode is at least 30 mpg, is the device 'ready' ?

 

I was referring to the EPA test procedure for plugin hybrids. Last I heard, EPA has not finalize the procedure yet.

If that causes fear, uncertainty and doubt, I did not cause it. I was simply pointing out a critical path in project management.

 

Now that GM has repaid their bailout loans, it's no longe "Government Motors.". Even then, I don't think the EPA wants media headlines plastered all over America that say"GM says Volt is on dealer lots, but they can't sell any because the EPA is being lazy."

 

Paying off a loan with borrowed $$$ doesn't free GM from being "Government Motors", esp. since the government still owns 60% of GM stock...which it can't sell either.

 

I think that you mean 'the max life cycle of a current vehicle'. In fact the average replacement of a vehicle by each owner is only recently extended to 5-7 yrs from the prior 4-6 yrs. Relatively few owners keep their vehicles longer than 10 yrs.

For the foreseeable future the Volt is not going to be available to the general public due to a) Pricing and b) limited supply and distribution. Maybe in 2015 they'll be more numerous.

I disagree that ICE's will be abruptly dumped. The NA buying public as in everything is very conservative and generally risk-averse. It's taken a solid 10 yrs to get a majority to even consider a hybrid vehicle. Even with this positive result the actual sales are less than 10% of the market. That means that over 50% of the buyers would seriously consider getting a hybrid but when they actually go plunk down cash only one out of ten actually buys a hybrid.

Maybe in the decade of the 20's PHEVs will reach the 10% acceptance rate. However if they public has gone though a major spike in fuel prices up to the $8/ gallon range or supply has suddenly been cutoff for some reason then there might be a seachange toward PHEVs and EVs. Right now everytime gas prices drop below $2.50 the bulk of the conservative buying public forgets that $5 / gal fuel is right around the corner.

 

Therein lies the rub. Because what you are saying is that the government's EPA is NOT done by the government's EPA ... it's done by the governments car company GM. How exasperating is that. Remember, this is the company that recently used loaned money, to payback loaned money ... and :
http://www.autoobserver.com/2009/05/gm-loses-6-billion-in-first-quarter.html
they used loaned money to advertise that spin:
GM ad glosses over the reality | detnews.com | The Detroit News
So GM intimates that they're making money now, even though they're not. It's getting so when you see GM's lips moving, you know they're telling a lie ... you just have to figure out what the lie is. Don't get me wrong ... I like to think the Volt will be a huge success. But it's like throwing a party for your malignant tumor.
(thank you cwerdna for the links)

 

I agree with the above - EV's are not going to be a significant segment of the US market for the next 10-20 years. Even at $5/gallon, gas is only expensive for inefficient ICE vehicles.

 

I see your point but this is misleading.

EV vs Series Hybrid:
What you describe here as a series hybrid is an EV (electrical vehicule). A series hybrid is another beast and includes diesel train locomotives, where an ICE drives a generator, which drives a motor, which drives the wheels (in series).

Note that I did not say that the Prius was a series hybrid. I said it was both a series and a parallel hybrid (both at the same time).

Series vs Parallel Hybrids:
- A series hybrid refers to the fact that power from the ICE is converted to electricity by a generator, which is then converted to mechanical energy by a motor. (ICE to Generator to Motor to Wheels).

- A parallels hybrid refers to the fact that power to the wheels can come both, mechanically, from an engine and from a motor (ICE to Wheels and/or Battery to Motor to Wheels). The Honda’s mild hybrids fits in this category.

In the Synergy Drive, both modes happen. When the engine is run, part of its power is mechanically pushed to the wheels (ICE to Wheels, like a parallel hybrid), while another part is used to run a 40kW electrical generator, which then sends electric power to the 60kW motor (ICE to Generator to Motor to Wheels). When accelerating quickly, power will also come from the battery, acting like an EV (Battery to Motor to Wheels). Also, and limited only by its battery pack output power (27kW), it can run solely on electrical power.

The fact that the Prius cannot run at high speed only on electric power is due to the fact that its battery is not big enough to do so and this has nothing to do with it being a series hybrid or not. Its 60kW motor could very easily run the car at high speeds; the Plug’in Prius, with its bigger battery pack, in fact do so.

And back to the Volt...
In conclusion, even GM doesn’t call the Volt a series hybrid; they rather call it an "extended range electrical vehicule". Only when its battery is depleted will it act as a series hybrid; for the first miles, it is purely an EV.

This may seem picky but I think it is fundamental to understand these technologies to know how they work and what are the differences.

 

It is good to read some good, common sense in this thread ... I had all but given up on PC ... So many of the threads have been overwhelmed by the EV crowd.

I applaud the EV's ....I am excited about their forthcoming availability, but they are not going significantly change the need for petroleum in my lifetime as some suggest. I have been mocked at the suggestion that asphalt, plastics, petro-chemicals, and almost every other product you can think of, will require the continued exploration, and utilization of petroleum for a very long time. Even the manufacture of alternative energy devices, and the distribution cables requires petroleum products.

 

There is no serial hybrid. The term is always series hybrid. It's an analogy to electrical engineering: in a series circuit the current flows through each device in turn (in series) while in a parallel circuit it is split and flows through each device at the same time.

A series hybrid car is mostly the same as a diesel-electric train: the engine turns a generator, which produces electric power, which flows to the motor, which turns to produce torque. Until recently, though, the trains did not have any electrical storage and simply varied the engine speed to match changing demand and so aren't true hybrids.

The difference between the series hybrid and the Prius-pattern is that the Prius does have a mechanical power path, which bypasses the conversion losses inherent in electrical transmission. That's great when driving on engine power, but there's a small amount of loss involved in spinning the planet gears, the sun gear, and MG1's rotor, when driving electrically. Also, the ICE has to turn - causing drag and some loss of energy - when driving above a certain speed, so that MG1 doesn't exceed its design limit. On the regular Prius this is 48mph (up from 42mph on the Gen 2 Prius) while on the plug-in Prius it's reportedly 60mph.

The question is whether there is a difference in electric power train losses when driving electrically, and if Toyota's is superior, if it's superior enough to outweigh the minor losses from the extra spun mass.

 

It will be close to 36 MPG because 2010 Smart fortwo gets 49.5 unadjusted combined MPG.

2010 Prius gets 70.9 unadjusted combined MPG (71.95 city / 69.64 highway).

EPA Source

 

Would a 115200 baud serial hybrid be considerably faster than a 9600 baud one? What type of parity should you use?

Tom

 

It is a serial hybrid like a serial killer.

 

I see the expression "serial hybrid" and "series hybrid" used interchangeably on the web.


Just as "serial circuit" is used interchangeably with "series circuit"

IEEE Spectrum: serial hybrid

 

Not to be confused with the new "cereal hybrid", which can also run on Wheat Bix and Corn Flakes.

 

But beware of the All-Bran cereal hybrid, which is know for its noxious emissions.

Tom

 

You know.. I've often wondered about those trains, as to why they were designed that way. Now, I know diesel submarines were designed this way but that was so they could run in "silent" mode. But what advantage does this series arrangement give to the train? Why not have the engine run the wheels directly? Wouldn't it be more efficient?

 

It's done that way because a mechanical transmission would not work as well. Locomotives need huge amounts of starting torque. The electric motors in a diesel-electric system are able to develop full torque at zero RPM. This is a big advantage when starting a train or climbing grades. It also allows the motors to be located right at the drive wheels, making for a much simpler mechanical arrangement. Dynamic braking is also a plus.

Diesel-electric submarines were designed that way because submarines needed to run from batteries when underwater.

Many ships also use diesel-electric drive systems. With ships this is done so that X prime movers can power Y propellers in any desired combination. The ship can cruise with only a fraction of the engines running, but then switch on more for additional power. It also makes for redundancy.

Lastly, some ships and tug boats use a diesel-electric system for fully rotating thrusters. Most modern tugs can point their propeller in any desired direction, letting the boat move sideways if necessary. The electrical power path makes this an easier task than some sort of mechanical drive shaft.

Tom

 

A motor provides full torque at 0 rpm, something an engine can only do at a high rpm.

Would like to be the clutch/torque converter in such locomotives?

A series approach avoid having one.

See [ame=http://en.wikipedia.org/wiki/Diesel_locomotive]Diesel locomotive - Wikipedia, the free encyclopedia[/ame]