The problem with series hybrids

[dcb]

Originally Posted by NeilBlanchard

Parallel hybrids are inherently more limited (than an EV or series hybrid) because they *must* use both motors in combination much of the time, and therefore they will weigh more, cost more, and they need a transmission.

I disagree,

the only time I would bolt the range extender parallel ICE onto my EV is when I am heading out of town. It isn't much of the time, but maybe %5 of the time that I have additional weight, and the transmission can be trivial and efficient, and the ev can sit in neutral when not needed. It is way more efficient than any serial setup I've heard of. It will weigh less and cost less than a generator and circuitry used in a series elecctric hybrid.

[NeilBlanchard]

Hi Dave,

A parallel hybrid design has several of choices that run between these three:

1) It can have a big enough ICE to be able to power the vehicle by itself, but it then has to have a transmission that lets work. The electric motor can be kept small, but the only advantages you gain are a small amount of regenerative braking, built in start/stop ability, and the ICE is only a bit smaller than it might otherwise be. The Honda system is close to this.

2) It can use either the electric alone, or the ICE alone to move the vehicle, but this requires each to be larger than otherwise, and the battery must be large enough to run for a reasonable period. It can also be operated in either series mode (see below). The Prius is approximately this design.

3) It can have a big enough electric motor to power the vehicle by itself at lower speeds, but then you have to a have a larger battery, and the small ICE must be used at highway/constant speeds (in order to justify it's use) and it still needs a transmission, if it is needed to climb hills by itself. I think this is going to be the most efficient parallel hybrid.

A series hybrid also has a range of choices:

1) It can use the ICE to directly generate power as required by the electric motor, and have the motor vary is RPM to match. You can even do this without any battery, though it should probably have a supercapacitor, at least, and possibly a small battery. Diesel/electric trains are like this.

2) It can use the ICE to generate enough power to run the electric motor directly and/or to charge the battery.

3) It can use a very small ICE to only charge the battery, and it would run at it's most efficient RPM (so ~37% efficient any time). This is the type that would seem to be the most efficient.

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For either type of electric/ICE hybrid, you can choose to have plug-in charging; and you can choose to have a supercapacitor to get more regenerative braking, because it can instantly absorb as much current as you can generate. This can then be used to either charge the battery (at a rate that is safe), or you can use the supercap to power the electric motor at a higher/faster rate than the battery can.

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In all the parallel hybrid arrangements, you have a larger ICE than in an series hybrid of the third type. And, all the parallel hybrids need a transmission. A parallel hybrid's only advantage is it can have a smaller battery, but it then cannot be a plug-in, and has more limited regenerative braking -- and this would preclude it being the third type that I listed above.

I would love to have lots of both parallel and series hybrids, to base our judgments on. But the fundamentals are that:

* ICE power at low speeds is (much) worse than electric power at low speeds, and they require warm up time, and they require much more regular maintenance.

* Electrics allow you to have regenerative braking.

* ICE is required (for now) to have long enough range to drive non-stop all day.

* Renewable energy sources must be used in order to be sustainable over the long term. Electricity offers more renewable sources right now, that are already more accessible.

Can we agree on these?

It comes down to how you achieve efficiency at highway speeds, and/or over longer ranges, I think.

[dcb]

Niel, I don't think you have understood me at all if you think those are the only options for parallel. Or your preconceptions have turned into absolutes and "requirements" for everyone else.

[user removed]

I've spent literally thousands of hours over the last decade researching the options as far as hybrid vehicles, as well as $30,000 pursuing a patent.

I don't spent that kind of money without due diligence, or that amount of time without the same diligence.

The EPA also predicted that you could build a hydraulic hybrid class 2 truck with a gross weight of 7800 pounds that averaged 59 MPG combined. Not sure about that one but the presentation was fairly convincing, but it did include advancements on motor designs that did not exist at the time of the prediction. Tha same prediction estimated that could be accimplished this year 2010.

I have the document if you don't believe me. and can provide you with a photo copy in this thread.

I have already posted a photo of the cumulative losses of electric hybrid regeneration compared to hydraulic regeneration, in a prior thread. EPA documents, not mine. I can post it again.

I went to Next Energy in Detroit and they are pursuing hydraulic hybrids. 4 years ago the wheel to wheel efficiency was 78%. Electric wqas 30%. Their figures, not mine.

By moving the motor to the wheel and accomplishing infinitely variable ratios, you have solved the issue of high speed inefficiency. Wheel speeds of 1000 RPM (over 100 MPH) keep efficiency above 90% in the bent axis pumps the EPA was using. Bent axis pumps are an ancient design dating back to WW2. They are reciprocating pumps and require low pressure circuit levels of 200 PSI to prevent cavitation. Mine is rotary and not reciprocating, low pressure circuit levels could potentially be 80% less.

Guys and Gals I can go on with this for hundreds of pages from memory. If you are serious about really understanding the potential efficiency of hydraulic hybrids, then lets keep it simple. Address each issue that you have a rational concern individually. I can provide evidence to refute your allegations, as well as independent scientific research to back up every claim I have made.

I have spent more time on this than it would require you to get a Masters degree from any University in the country.

My design has addressed every issue you bring up in this discussion. It is based on over 37 years of experience and intimate knowledge of automotive operational systems, by a person whose IQ is the equal to anyone here.

That makes me an authority on the subject of hydraulic hybrids. My design could weigh 1pound and power a bicycle. Parker Hannifin has been sponsoring a contest called the "Chainless Challenge". It's purpose is to get Universities to produce bicycle designs that utilize hydraulic powertrains in a competition to see who can come up with the best configuration.

A "clean sheet of paper"

The technology of infinitely variable transmissions and accumulators specifically designed for automotive applications is fairly new. The EPA produced a test mule passenger car 10years ago that averaged 80 MPG and weighed 3800 pounds.

At the end on their considerable research and development, they basically begged for another design that started from a "clean sheet of paper" as far as power trains for HH vehicles.

That's what I did. That's why I spent the enormous amount of time and a considerable amount of money in pursuit of my dream. That dream becomes an issued patent in about 2 months.

That my friends is the very soul of this forum. To increase our understanding and application of greater efficiency in vehicles. My experience equals or surpasses any other person on this planet in that specific dedication, and I am not mentally handicapped. That does NOT mean my abilities are any greater than any other member of this forum. It merely matches the statement by Einstein that genius is 1% inspiration and 99 percent perspiration. I have paid admission to that group, with obsessive determination to a cause I think has the potential to change transportation as we know it.

I have not come here with ridiculous claims, or flim flam sales pitches, or nefarious schemes to separate anyone here from a single penny.

What I ask is for you to use the brains God gave you and try to understand that there are other options above the status quo. Lack of understanding is our greatest enemy. If we choose to ignore any rational pathway to our common goal, then we risk loosing a race that is planetary, not local.

Nations outside our borders are not limited to specific development pathways, and if they get the jump on us we will be playing catch up again, the same we we had to play catch up with the Japanese when the oil spigots were shut off in 1973.

I will make this statement one more time. If you don't believe what I am saying, at least you should allow me enough of your attention to let me show you what a decade of research has produced. They don't post articles in the Journal of the American Society of Mechanical Engineers to support charlatans.

One of the major engineering schools does not spend a year doing all the research that 8senior engineering students, led by a MIT degreed Doctor of Engineering would accumulate in a year of work, to conclude that the hydraulic option is an effective solution.

Now you can choose to ignore further evidence, or you can follow a natural curiosity I have found to be almost universal in intelligent people, and just try to understand.

I know the potential of this system, several other groups of intelligent people have developed similar systems, some of which are Automotive X prize contestants. (Links posted already).

You see my goal is to provide cheap hybrid transportation. I have covered every reservation you have presented. If you doubt that then lets address those specific issues one at a time. If my evidence does not convince you there is an alternative, then I will not waste my time further in this forum.

With the capital necessary I can provide the design for a car that gets 100 MPG average, weighs 2200 ponds, provides all necessary creature comforts, and cost $15000.

Its that simple, and the design itself is so ridiculously simple its almost unbelievable. Any competent manufacturer can produce it for 66% of the stated selling price, and it could be on the road in 3 years max.

It does not require electric motors or batteries, but they could be the fuel consuming source of accumulator pressure. The could see their range enhanced with a combination of the two systems.

As I said before the source of consumable energy matters not to me. The true objective is to extract the maximum amount of work out of any source. If you don't understand that is the true objective, then I am wasting my time and yours.

regards
Mech

[NeilBlanchard]

Hi Dave,

Originally Posted by dcb

Niel, I don't think you have understood me at all if you think those are the only options for parallel. Or your preconceptions have turned into absolutes and "requirements" for everyone else.

Q: What is a parallel hybrid design that falls outside of the *range* that I outlined? (I was concentrating on electric/ICE hybrids.)

Q: Can a hydraulic hybrid system be made small to fit in a 4-seat car?

[dcb]

Neil, in all three examples you increase the size of the engines for a simple parallel setup when you should be reducing them. That is misinformaton posing as fact. Peak efficiency is improved in an optimized parallel setup for a target load/speed, by a good %20 over a series hybrid.

At some point efficiency will fall off as you leave the target speed(or speeds if you make an efficient trans) and load, but you (the driver) have options then as well, i.e. recharge the battery/supercap if the load isn't sufficient, or discharge the battery if you need more power.

So the range where optimized series *might* surpass a well managed optimized parallel system is much smaller than you might think.

But storage, again, is not Germaine to this discussion, they both have it, leave it out. Focus on the transmission losses between the ICE and wheels in BOTH cases. I can operate near bscf all day with enough gears, albeit not at constant speed, but I don't care about that.



Mech, chill out and answer a straight question. We have to eliminate some variables and look at the component parts here.

Q. MECH, assume you are operating a vehicle at a constant speed and load, with an ICE that has a 98% efficient transmission that is cheap and lightweight, and the engine is operating at bsfc. Lets assume a fairly clean design and the engine only needs to put out 15hp to cruise @55 mph.

It isn't directly relevant to the question, but this is where the bar for peak parallel/direct drive efficiency is at and these are not part of the variables for this question.

Can you give accurate assessments of how converting this relatively constant speed/load operation to a hydraulic will affect:
1. efficiency, in terms of how much power leaving the engine shaft gets to the wheels.
2. weight at the efficiency.
3. cost that weight/efficiency
4. additional space needed in cubic feet to house the components at that weight/cost/efficiency/no word games/ etc.

Also I would say the assume you have a hydraulic transformer in there (you neglected to mention its efficiency) if you wish to also claim the benefits of having a hydraulic system, but I don't care about storage right now, we will come to that, but it isn't a factor in extended constant load/speed operation.

[user removed]

http://www.innas.com/Assets/files/Hydrid%20brochure.pdf

Take the time to read this, PLEASE-IT IS CRUCIAL. It's 1.5 Meg and covers just about everything.

My design is self adjusting and needs no transformer. The INNAS design uses fixed displacement in wheel drives and requires a transformer. Losses are higher due to continuous fluid movement in fixed displacement motors. Mine has no fluid movement without any stroke.

Fluid movement only occurs if your are applying or recovering energy, with my design.

I did not include a transformer in my design because it does not exist. Stroke adjustment at each in wheel drive accomplishes infinite variations in displacement.

DCB while you may not care about the speed variations involved in P&G, other drivers around you can get really aggravated with your actions. Not relevant if you are not interfering with their driving, as would be if you are alone on the road, but dangerous in high traffic density situations where others do not understand your actions and their unpredictability from their perspective.

Pay particular attention to the engine, which is the same in both vehicles. In fact the vehicles are identical other than the power train changes. Also a fairly low power efficient diesel engine.

dcb, also thanks for rejoining the discussion, keep the questions coming.

regards
Mech

[dcb]

ok, but can you answer the previous questions?

[user removed]

Do me one small favor.

If the INNAS presentation does not address any question, then I will be glad to follow up.

I hurt my back Tuesday and I need to take a break for a couple of hours.

I promise to answer all questions, with plenty of evidence to support the answers.

In some cases I may have to predict something that I can not confirm with factual evidence. If that is necessary I will specify that it is an estimation or prediction.

I have pounds of documentation.

Be back after dinner, about 7 PM eastern.

regards
Mech

[dcb]

I did look at that initially when you posted it and again now and could not discern reasonably accurate responses to my question(s) here http://ecomodder.com/forum/showthrea...tml#post156015 .

Thanks,
Dave.