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CarCrazy
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Oh ..., what a waste. Diesel electric series hybrid will do the job even at current state of affairs.
Gentlemen, please, take a look at that https://energy.gov/sites/prod/files/2014/02/f8/fctt_roadmap_june2013.pdf especially at durability of fuel cells. They cannot reach 5000h (equivalent of 150000 miles) target. Never mind 30K-50K hours target for trucks (equivalent of 1M miles). The energy source is the problem too but again the cyclobility of fuel cells is, say, bad. If one turns them on and keeps them on - they can last way longer but otherwise ... People are working to improve it but the progress is very slow. Besides this, low temperature fuel cells suffer from efficiency issues as well. What I am trying to say is that all these is highly subsidized by ... you - the tax payer.
Not so fast, Harvey. As much as it is win-win-many times win concept (800V there is), it presents colossal challenges to motor drive/motor system. It is specifically related to motor reliability due to corona discharge problems which is a single major failure reason of electric motors. Besides this, the leadership of Mr. Fisker has tainted reputation (Fisker Automotive, remember?). At this voltage level everything is supposed to be done not only right but perfect. One slip and explosion is inevitable. We shall see, though.
Please, never forget about the stray fields between two coils and problems associated with alignment. In ideal world it might be good but it is still not in mass production and there are many reasons for that. I am sure that a lot of people are working on this but ... not there yet. Besides this, the standard limiting the switching frequency to 85kHz is just ... well, questionable, limiting innovations in the field. The company is in business for many years but is still supported by grants which says a lot. Just being a little ... realistic.
DaveD, "Adoption of WBG power electronics may be constrained by their cost and reliability." - this is one of the "show stoppers" at this point, especially reliability. There are tons of articles in Power Electronics magazines showing the advantages of WBG semiconductors while ... none of motor drives are in production. There are many reasons for that besides the mentioned one. All my attempts to overcome "non invented here" type of thinking have failed, so far. There are solutions but ... well it is not a subject of the blog. Actually, cost is not a big problem whatsoever.
It seems to me, the fuel efficiency is achieved not because of "optimized gear ratio" but because the new transmission imitates the manual one preventing unnecessary slippage of automatic (torque converter).
Although the results are promising, as a power electronics guy, I am still in favor of the structure as following: Diesel - clutch - motor/generator - clutch - motor/generator - wheels. The level of the power of motors used in this car (115kW) is already enough to get rid of DSG unit. The price of motors/power electronics, though, is still big "?".
There are some basic concerns about wireless power transfer over "whatever distance" (20cm in the described case): 1. Switching frequency 2. Inductive heating of everything around. Efficiency is not a problem. Proper matching will do the job. Some ... (almost said that) in power electronics leadership established 85kHz standard. It is a problem for coupling and leakage fields. We are talking kilowatts, guys. Big kilowatts too. Misalign your car just a little bit and 20cm gap will "melt all metal around". Higher switching frequency provides better coupling (less leakage as the result). Also, there is nothing wrong of "dropping" the receiving coil on to the antenna (well, with small gap remaining) and the problem is over. Hold on, ain't we coming back to GM concept of sort for their EV1 insertable charger? ...and there is nothing wrong about it. It was efficient, the leakage fields were minimized... Alon Musk is a smart person and he might be aware of all these problems.
I am with Henry on this matter. ABB motors with more sophisticated control would be an excellent choice for automotive industry. I have not seen liquid cooled design yet (of these motors) but when it happens it would produce one of the most power dense machines. Torque ripple can be addressed via smart motor drive system even at low RPM. Permanent magnet machines paved the way but no more required.
So far, thorium based (molten salt reactors) are found to be the best for the job... but there is no "dual" use (weaponized plutonium) as it is in case with uranium. Although this type of reactor is known for generations and it is safe and 4 times smaller, the development was stalled due to absence of military interests. It is a shame again: the nice thing was invented in USA to be under development in India.
This is true: the anticipated improvement is dramatic. However, it is not going to happen without substantial improvements in motors (peak power available) and motor drives (peak power available, again). So far, in most modern hybrids the electrical motors play somewhat supplemental role due to their power limitations. Only Porsche 918 hybrid has decent electrical power capability allowing deceleration of 0.5 G (most of hybrids can do only up to 0.15 G). Tesla is close but it is pure electric car. So, there is still "long way in dunes" before true hybrid happens.
It is amazing how Europeans are trying to stay ahead of the competition from North America. As power electronics guy I can state that they are ahead of USA in Hybrid Buses and vehicle electrification in general. Nothing is ideal yet but those people understand where the future is. Our high level gentlemen in this industry feel comfortable and protected from competition. Open the borders and a whole American hybrid world will be wiped out by better European design
...and "we" are saying that Walmart is bad. I am not sure that Capstone is a very good choice due to efficiency of range extender but the power density is very high (higher than diesels). If one needs to hide the whole power train - this is the way to go. Again, the efficiency of Capstone is...
I do not know what considerations were used in this frequency choice but it limits substantially the progress in the field. In general, the higher frequency is the smaller passive resonant components can be (integral part of wireless energy transfer). Besides this, shaping the electro-magnetic field is much easier at higher frequencies. In my humble opinion as a power electronics designer, several hundreds of kHz is not the limit. These inverters should not interfere with AM band but otherwise 85kHz sounds too low and limiting. Also, "The SAE International Task Force is currently working on completing the remaining interoperability topics, including factors such as the minimum coupling factor “k”, alignment, and coil geometries"- sounds like framing for the existing products. Define the allowed radiation ...and that is all. Somebody is definitely trying to prevent the competition from leapfrogging inventions. Mind boggling. For those SAE Bureaucracy "survival of the fittest" is like red color for bulls. Regulate, regulate with no thinking (non required).
1. This engine architecture is used by BMW and Audi for many years (not in diesels mostly), so what is new again...? 2. @gryf Both Bob Lutz creations are too expensive and less efficient than advertised otherwise they would overflow the market. ...and there are many reasons for that. Even the general idea is right it does not mean that it is (was) implemented correctly.
Of course it is much better for Obama to support a dictatorship regime rather than to buy from our friends.
Gentlemen! The motors are very (sometimes 96%) or more efficient if the design is right and ... the motor driver is right. As a power electronics designer I see NO need for multispeed transmission but I do see needs for motor driver. There are so many types of losses associated with ineffective motor driving that it is inevitable that it will be addressed rather sooner than later. BTW the solution exists.
This is from their web site,so give it some time and let's see how it works long term heating everything metal around if not alighed perfectly: How easy is it to align the Vehicle Adapter and Parking Pad? "Most drivers achieve successful alignment on their first try. As you approach the Parking Pad, the wall-mounted Control Panel displays bright, easy-to-follow directional arrows to guide your alignment. We like to say our system allows for a greater margin of error than most garages and parking spaces. In fact, we’ve designed the system to operate efficiently even if your EV isn’t perfectly aligned"(This remains to be seen -CarCrazy)
As impressive mechanically still as much disappointing electrically. From power electronics prospective they could have done much better but...
This is interesting but... why to reinvent the wheel? If propulsion electrical system is powerful enough (at least peak power powerful enough) it is able to provide breaking deceleration as high as 1g (whatever tires allow). So, the iBoost is an intermediate (handicapped) solution before normal series hybrids take over industry. I would be delighted to work on supercaps + battery energy storage system capable of absorbing full breaking energy. In this case semiconductors must be rated for high power for short runs but system's cooling capability should be designed for average power only.
Roger: You are right - the power reduction is inevitable in valve manipulation case. It can potentially be addressed via turbo- or supercharging if necessary. However, to your point, nothing can beat electrical motors for power boosting. So, hybrid drive train + valve manipulation = better fuel economy with no additional mechanical complications on the engine side.
It looks like that variable compression ratio can be achieved just through valves (intake-exhaust) manipulation. So, if electromagnetic valve lifters are used no additional mechanizms are required.
To add to the post above: Solindra and Fisker Automotive are good examples that gov. help does not work if something is wrong with a company.
Potentially they can be but how do those bozos know what industry to support and to what extend? Gov. "Experts" will be promoting industries they are in. This can go on and on. The government potentially can support something where private industry already invested a lot with obvious success and it (private industry) needs a little oomps to overcome the hurdle. But I am no sure even in that.