GM Announces New Hybrid System

[bat4255]

Originally Posted by daniel

Since when does an announcement by GM that they will build this or that car qualify as news?

+1

Show me one that I can buy, then I may be interested, and take a look.

Until then, it's just "Pie in the Sky", and should stay in Popular Mechanics.

[usbseawolf2000]

Originally Posted by finman

HSD-killer
That will be HSD-II

Originally Posted by finman

superiority of HSD.

I just love to see that.

[daniel]

Originally Posted by micheal

No doubt that hybrids are a stop-gap, but the idea is that methods used in full hybrids can be utilized in the next generation of vehicles. ...

HSD is a brilliant system. But I don't see the technology transferring to the future. I don't believe GM will ever build the Volt, and their announced battery range for it is too short (they want you to still burn as much gas as they can force on you).

HOWEVER, the series-hybrid concept is what we really need for the future. Unlike HSD, the series hybrid would allow you to do all your city driving with 100% grid power and zero gasoline. This is a qualitative improvement, not merely a quantitative improvement in gas mileage. And as electric-storage methods improve, the series hybrid moves smoothly into pure EV.

HSD is as good as a gas-powered car gets. But its need to use the gas engine under some conditions even when the battery is still full makes it a poor choice for those of us who want to get away from gas, and not merely get incrementally-improved fuel economy.

Series hybrid also opens the way for 4 independent motors in the wheels, allowing for better traction (every wheel gets power when other wheels slip) and eliminating the problems some Prius drivers have with TC (the computer could just reduce power to the wheel that's slipping: no need to slow the whole engine to protect MG1).

[Flying White Dutchman]

Originally Posted by daniel

HSD is a brilliant system. But I don't see the technology transferring to the future. I don't believe GM will ever build the Volt, and their announced battery range for it is too short (they want you to still burn as much gas as they can force on you).

HOWEVER, the series-hybrid concept is what we really need for the future. Unlike HSD, the series hybrid would allow you to do all your city driving with 100% grid power and zero gasoline. This is a qualitative improvement, not merely a quantitative improvement in gas mileage. And as electric-storage methods improve, the series hybrid moves smoothly into pure EV.

HSD is as good as a gas-powered car gets. But its need to use the gas engine under some conditions even when the battery is still full makes it a poor choice for those of us who want to get away from gas, and not merely get incrementally-improved fuel economy.

Series hybrid also opens the way for 4 independent motors in the wheels, allowing for better traction (every wheel gets power when other wheels slip) and eliminating the problems some Prius drivers have with TC (the computer could just reduce power to the wheel that's slipping: no need to slow the whole engine to protect MG1).

put a bigger elec motor in the HSD ( and battery pack )

[micheal]

Originally Posted by daniel

HSD is a brilliant system. But I don't see the technology transferring to the future. I don't believe GM will ever build the Volt, and their announced battery range for it is too short (they want you to still burn as much gas as they can force on you).

HOWEVER, the series-hybrid concept is what we really need for the future. Unlike HSD, the series hybrid would allow you to do all your city driving with 100% grid power and zero gasoline. This is a qualitative improvement, not merely a quantitative improvement in gas mileage. And as electric-storage methods improve, the series hybrid moves smoothly into pure EV.

HSD is as good as a gas-powered car gets. But its need to use the gas engine under some conditions even when the battery is still full makes it a poor choice for those of us who want to get away from gas, and not merely get incrementally-improved fuel economy.

Series hybrid also opens the way for 4 independent motors in the wheels, allowing for better traction (every wheel gets power when other wheels slip) and eliminating the problems some Prius drivers have with TC (the computer could just reduce power to the wheel that's slipping: no need to slow the whole engine to protect MG1).

I'm not sure I really follow you. None of the things you mentioned are impossible with a full hybrid system. Now while the current formulation of HSD makes the gas engine necessary even for short trips, this is something that could be easily changed through software and other changes. As battery packs become bigger and better, then the software could be modified to allow for more and more miles driven on electric only (and higher speeds like the Li-On Prius test cars).

Full hybrids are already utilizing a larger battery than series hybrids, and as battery technology increases this could be easily taken advantage of via HSD (more so than it seems in current series hybrids). Now, I don't think the current HSD will be exactly the same in the next generation of vehicles, but it's flexibility in how it is implemented will be useful. As time goes on, better batteries and bigger electric motors could be introduced and changes made to further reduce the need for a gas engine until it is no longer needed.

As far as the four independent motors to the wheels why couldn't this be used in HSD? The TC problems appeared to be more due to faulty implementation rather than a widespread problem due to HSD design based on recent models (2005+) not reporting the same problems as early models.

[daniel]

Originally Posted by micheal

I'm not sure I really follow you. None of the things you mentioned are impossible with a full hybrid system.

<snip>

As far as the four independent motors to the wheels why couldn't this be used in HSD? The TC problems appeared to be more due to faulty implementation rather than a widespread problem due to HSD design based on recent models (2005+) not reporting the same problems as early models.

First off, you cannot have independent wheel motors with HSD because HSD is defined by one gas engine, two electric motors, and the PSD linking everything together. With independent wheel motors there is no PSD. Therefore it's not HSD. It's a whole different animal.

Yes, you could enlarge MG2 and alter the geometry of the PSD to allow for more acceleration and higher speed with HSD. But this misses the whole point of HSD: HSD is a system designed from the ground up to use gas and electric simultaneously. EV or "stealth" mode is an accident of the fact that sometimes the battery becomes full and the car must run on electric for a few minutes to bring the battery back to the mid-range where it wants to be. A bigger battery is more efficient because it's better able to buffer the power needs of the car, but was not used due to the cost.

But as you move away from 100% gasoline power (as the current Prius is) to partial or full grid power, the rationale for a car designed to use gas and electric simultaneously disappears. Now you want a car optimized for electric use, where the gas engine is just a range extender. At this point the power from the engine is completely buffered, and when running, the engine can always be exactly at its most efficient rpm and power output. This is not possible with HSD due to the geometry of the PSD.

HSD is so efficient primarily because buffering its power output allows it to run closer to its most efficient rpm and power output, and some of the torque can be provided by the electric motor. But a full EV gets all its torque from the electric motor(s) and a plug-in series hybrid has total buffering of power from the engine (when the engine is needed at all) and so can be even more efficient than HSD.

The Prius is the easiest car for a backyard mechanic to convert to PHEV because it has the control circuitry and the electric motors already. But it can only ever get about half its energy from gas. And because of the way it gets its best operation by using gas and electric together, it's not a good design for a PHEV built by a company that has the resources to design a PHEV from the ground up.

[ken1784]

Originally Posted by Flying White Dutchman

put a bigger elec motor in the HSD ( and battery pack )

Do you know Prius history?
NHW-10 40 modules 76 kg
NHW-11 38 modules 52 kg
NHW-20 28 modules 45 kg
The HV battery becomes smaller and lighter, but vehicle performance and mileage are insreasing.
That's the innovation.

Ken@Japan

[daniel]

Originally Posted by ken1784

Do you know Prius history?
NHW-10 40 modules 76 kg
NHW-11 38 modules 52 kg
NHW-20 28 modules 45 kg
The HV battery becomes smaller and lighter, but vehicle performance and mileage are insreasing.
That's the innovation.

Ken@Japan

And yet wasn't it Wayne Brown who first put a second battery pack in a Prius (not plug-in) and without making any other changes achieved a significant increase in efficiency (fuel economy)?

Toyota improved the hybrid system so much that even with a smaller battery they improved FE, but Wayne Brown showed that with a bigger battery FE would be even greater.

Toyota, however, has to take cost into account.

[sl7vk]

Originally Posted by Jonnycat26

Try reading it before asking questions, it's always helpful.

But to summarize it for you, it's a new version of BAS which, as one commenter put it, blurs the lines between mild and full hybrids. It's capable of driving the car on it's own, yet retains the simplicity and cost effectiveness of the original BAS system.

It is interesting that the lines between a 'mild' and 'full' hybrid are starting to blur... Honda did it with the last version of IMA, and GM is taking it a step further with the next version of BAS.

And to preempt John's next comment... the type of hybrid system used has nothing to do with emissions.

Have you bought that Saturn Aura Hybrid that you raved about a year ago yet? Or are you still motoring about in a Prius.....

[micheal]

Originally Posted by daniel

First off, you cannot have independent wheel motors with HSD because HSD is defined by one gas engine, two electric motors, and the PSD linking everything together. With independent wheel motors there is no PSD. Therefore it's not HSD. It's a whole different animal.

Yes, you could enlarge MG2 and alter the geometry of the PSD to allow for more acceleration and higher speed with HSD. But this misses the whole point of HSD: HSD is a system designed from the ground up to use gas and electric simultaneously. EV or "stealth" mode is an accident of the fact that sometimes the battery becomes full and the car must run on electric for a few minutes to bring the battery back to the mid-range where it wants to be. A bigger battery is more efficient because it's better able to buffer the power needs of the car, but was not used due to the cost.

But as you move away from 100% gasoline power (as the current Prius is) to partial or full grid power, the rationale for a car designed to use gas and electric simultaneously disappears. Now you want a car optimized for electric use, where the gas engine is just a range extender. At this point the power from the engine is completely buffered, and when running, the engine can always be exactly at its most efficient rpm and power output. This is not possible with HSD due to the geometry of the PSD.

HSD is so efficient primarily because buffering its power output allows it to run closer to its most efficient rpm and power output, and some of the torque can be provided by the electric motor. But a full EV gets all its torque from the electric motor(s) and a plug-in series hybrid has total buffering of power from the engine (when the engine is needed at all) and so can be even more efficient than HSD.

The Prius is the easiest car for a backyard mechanic to convert to PHEV because it has the control circuitry and the electric motors already. But it can only ever get about half its energy from gas. And because of the way it gets its best operation by using gas and electric together, it's not a good design for a PHEV built by a company that has the resources to design a PHEV from the ground up.

I think the main issue of confusion is that you are assuming I meant HSD in it's current form is going to be same HSD that will be utilized in the next generation of vehicles. In the end, I am not entirely convinced that the next set of vehicles will be full EVs based on a number of factors and that extended-range plug-ins are going to be around for longer than many EV proponents think.

I don't think what it was designed to do be in in first iteration is the same it is going to be 3 or 4 steps downs the road. Even in the test plug-in Pri that Toyota has used in Tokyo and the US allow for an EV mode (that is purposeful, not accidental at higher speeds and for longer distances with just more batteries and software changes as already discussed http://priuschat.com/forums/prius-hy...play-info.html.

Now when electric vehicles due arrive, I can't speak to what changes will be necessary into HSD to make it able to be used in such a vehicle since I'm not an automotive engineer. However, Toyota's engineers continue to make changes to the HSD to make it closer to what most of us hope for, EVs that will virtually eliminate the need for gas on a daily basis. My assertion is that the HSD up to this point has depended on gas and electric together because that was the most cost effective way to meet the goals of range, emissions, and convenience. The test PHEV's made by Toyota are enough evidence to me that they still left the door open for EV travel for a significant distance.