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My opinion on how an electric car should be built/work

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January 6, 2012 2:05:57 PM

O.K. One thing that I noticed is that electric vehicles have limited range with their batteries and that these batteries are heavy and very expensive also with a limited lifetime.I recently read up about Witricity the company and how it has had success with the wireless transmission
of electricity with a very high efficiency of between 90 to 95% using oscillating magnetic fields with the resonance effect.
See here.
http://en.wikipedia.org/wiki/WiTricity

Originally the inventor Nikola Tesla experimented with wireless transmission of electricity with the Tesla Coil however the method and efficiency wasn't so good though he was an amazing inventive man quite ahead of his time.It looks as if Witricity has made good on this wireless transmission of electricity in a new way though.

Anyway my idea for an electric car would be to have powered and likely sensor equipped roads,highways and Interstates with much less expensive electric vehicles that carry no batteries (maybe?) on them and thereby reduce their overall weight thereby increasing their energy efficiency,vastly reduce the cost (no pricey batteries) and give them unlimited driving range without the need for time consuming battery charging.Witricity on their site only mentions charging electric cars and they have a development kit for companies.I would prefer to go much further.

In addition a magnetic oscillating electricity producing road or even sidewalk would enable power to other more efficient (less mass) personal vehicles like electric bicycles,those EPAMD electric scooters,wheelchairs (on sidewalks).
As we know electric brushless motors are highly efficient at producing mechanical work at between 75 to 90% efficiency compared to the pathetic efficiency of a fossil fuel powered Internal Combustion Engine at 18 to 20% efficiency.The main drawback with electric vehicles has always been their low energy density batteries so why not just eliminate those batteries
January 6, 2012 11:18:56 PM

What impact will the magnetic fields have on a person? If it has no adverse affect that would be a killer idea. The making of the batteries in hybrid cars are horrific to the environment as well as expensive.
January 7, 2012 3:49:43 AM

It has no adverse health effects.WiTricity has a few demonstration products out there like a wireless powered Haier LCD TV.
Here are some videos on youtube of smaller demonstrations.EV charging and more demonstrated power was mentioned.
http://www.youtube.com/watch?v=wbCUMhkEhTo

http://www.youtube.com/watch?v=rMEg7yR3WoM

http://www.youtube.com/watch?v=FXDCR41huhQ

Here is the 3.3 Kw EV Charging kit.Just a little more power and no more need of even charging batteries (probably would take a few of these modules which work under concrete etc).I don't know why they didn't make the logical jump from just charging a EV's battery to powering the vehicle completely without batteries.
If roads were built this way that company would be enormously rich if such a transportation infrastructure was built.

http://www.witricity.com/pages/ev-charging-system.html
Related resources
a b F Wireless
January 11, 2012 7:05:51 PM

Of course, the tough question is who will pay for the immense infrastructure costs needed to install this along major roads and highways? And who will pay for the added expense for highway repairs?

Also, while the transfer efficiency may be very high from the road to the vehicle, there will still be major transmission losses from the power plants to the locations along the highways.
January 12, 2012 1:15:45 PM

Those are indeed interesting questions.I suppose wireless electric motorcycles,scooters,cars and trucks will have be metered (perhaps once per month or per year) to pay for electrical consumption.Perhaps a years worth of average travel costs (12,000 miles) could be added at initial vehicle purchase.If the electrical use charges were once per year it could be performed at the time when vehicle registration took place (There could be a monthly billing plan too).One could make it free for much more efficient vehicles which wouldn't use much power (negligible) or travel far like e bikes or EPAMD scooters or electric wheelchairs.Of course added road maintenance or expansion costs would have to be added.To do this at first there would have to be initially a demonstration road (for testing) and eventually a highway or modified portion of the Interstate Highway (Conventional Fossil Fueled Vehicles could still use this road although they would not benefit from it's wireless power).
In most streets of cities and county roads in the United States the tax comes instead from property taxes and general funds.Gas taxes pay for Interstate Highways and Highways though I believe that some of it is paid also by property taxes.
Lots of people complain when they feel cyclists don't pay for streets and roads but that is not completely true (only non tax paying cyclists don't pay).Cyclists and EPAMD users should probably get use free (minor electrical usage too) because they also pay for streets and roads and there is much less use by them.In addition they are not too very damaging to streets so maintenance costs by these vehicles would be negligible.
The transmission (gear train) loses of conventional automobiles reduce their efficiency by about 5 or 6 per cent somewhere around that figure.It would be similar for electric motor propulsion too.
Electrical Transmission losses are not very high that was one of the battles of the currents between AC vs DC well over a century ago.DC current transmission loses over distances were high and hence Thomas Edison lost his battle against Nikola Tesla and Westinghouse.

I suppose that the big question is this economically viable.Possibly with densified or heavily traveled Interstates,Highways,County Roads and City Streets.Not so in much less traveled areas.That's a question that would require a demonstration road with a wireless powered car or truck.It won't work unless it is economically viable (competes somewhat on par with current roads with conventional fossil fueled vehicles and their included costs per travel (also environmental concerns should be raised less damaging CO2 for electric vs bad CO2 emissions for fossil fueled less efficient vehicles).

Another consideration with electrified roads should power to them be supplied from distant power generation plants or would it be better to have solar,wind turbine arrays etc close next to Interstates to greatly assist in powering them (Ideal in certain locales).

Autonomy (robotic,computerized) would be an ideal marriage with a wirelessly powered electric car,truck etc because of the near (or hope complete) elimination of drunk drivers,distracted drivers or bad judgement instead with robotic driving.Ever since the creation of fossil fueled cars and trucks in the United States alone all vehicle deaths totaled a staggering 3.5 million total and 250 million total American civilians were maimed and injured which is a mind boggling figure.It would be ideal to eliminate stolen vehicles too or criminals attempting to utilize vehicles for crimes such as burglary,robbery and attempting to elude law enforcement.Such electrified vehicles could be remotely shut down.I suppose a criminal could turn to an alternative like a non autonomous wireless electric motorcycle or scooter or even perhaps a electric bike or EPAMD.However other civilians,homes etc would be in less of a threat by not having desperate criminals driving heavy vehicles (very destructive when they crash).The non autonomous motorcycle or scooter though could still be somewhat computerized and have remote shut down features (this might be circumvented though).

With autonomy and wireless electric vehicles those negatively impacted (mostly economically wise) would be the petroleum industry and workers (though this could shift towards using these chemicals to produce the vehicles,infrastructure),the law enforcement industry,judges,lawyers,prisons and jails,traffic courts,red light camera industry,parking enforcement,insurance industry,fossil fuel vehicle manufacturers,auto repair shops (lesser need).The legitimate consumer could gain enormous benefit if viable.

Anyway I don't have all the answers.It's just some ideas.
January 12, 2012 11:30:57 PM

It'd never work where I live but like you had said the possibility of it in a heavily populated area could make it feasible. If something like that were to be utilized in a city one tesla coil might be able to do a good few surrounding blocks at once. I think something like public transportation in a city would be a good starting point/ experiment.
January 13, 2012 12:26:11 AM

It doesn't use a Tesla Coil.It uses a different (safer and much more efficient) principle to transfer electricity wirelessly.The company WiTricity is developing the apparatus for consumer goods.They do have a 3.3 Kilowatt Electric Vehicle charging development kit that can be acquired by interested companies though.However they never mentioned using it to power Electric Cars directly (that would require more power (or multiple 3.3 kw modules) although perhaps sufficient for a low speed under 30 mph electric scooter or easily an electric bike).The units to have 90 per cent efficiency have a transmission range of only up to 20 centimeters (about 8 inches) which is barely enough clearance for a receiver (coil) unit on the bottom of the vehicle to the road where the transmitting surface is located.Of course that's only the EV development kit.The range on the wireless Haier TV from their video looked like a lot better.
Yes, a public transit system would make a nice demonstration too.
January 13, 2012 11:27:08 PM

I'm wondering if it can be made to send a 480v or 600v 3phase power. If so then the electric motors that can be used would be more efficient, lighter, and easier starting vs a single phase motor. The inrush for initial starting would be a lower amperage as well.
January 14, 2012 9:25:10 AM

I don't see why not.The received power could be easily converted on the vehicle side as long as the overall power (wattage hours) was sufficient.Too much power (either voltage or amperage) would cause damage hence there would have to be a power management system on board whatever type of EV which would be fairly simple.
January 14, 2012 2:30:16 PM

But by being converting on the car side by a step up transformer you'll be losing more efficiency and adding weight. A 100kw step up transformer has got to be 400+ lbs. If it is able to send a usable voltage to the car it would be tremendously better. I got to talk to one of my electricians about this and see what his ideas are with this.
January 14, 2012 8:54:54 PM

I see about the added weight.A Nissan LEAF for an example weighs a very hefty 3,354 pounds or 1,521 kg according to Wikipedia and has a 80kw (110 hp) electric motor.
Reduce the weight (mass) of the vehicle in half (it can be done) and it would only require half as much power to travel the same speeds (removing the batteries,battery safety enclosure,cooling etc other junk).Reducing vehicle weight is very important in increasing efficiency.If as you say a 100kw transformer weighs around 400 pounds then a 40 kw electric motor would require a 160 pound transformer (heavy but workable).Another thought are their lighter or could there possibly be lighter high efficiency transformers say half the weight in material so for example a 160 pound transformer be replaced with a lighter 80 pound one that could work with 40 kw?
In electrical equipment cooling the device (like traveling in the air with the component having heatsinks) can enable it to utilize more power without failure.An example of this would be with modern CPU's and heatsinks and fans.Before the Intel Pentium CPU came out older CPU's didn't have heatsinks and fans.It likely would be possible to aircool the transformer thereby enabling one to reduce it's weight.
Still a lot of electrical power.Remember that EV development kit module is rated at only 3.3 kw though 3.3 kw by itself would easily power a not street legal electric bicycle to 45 mph speeds or power a heavier low speed scooter to 30 mph.It would take about a dozen of those 3.3 kw kits and receivers to get up to 40 kw or so.Obviously a truck for instance would have to be larger and have more receivers to capture more electrical power.
The original pre war (WW2) Volkswagen Beetle ,the wartime type 82 K├╝belwagen and the amphibious wartime type 166 Schwimmwagen only had a meager 25 hp fossil fuel motor.Later on the hp increased but so greatly did the weight.Originally it was a very lightweight nimble vehicle.At 40 kw that should be somewhere around 55 to 60 hp for an electric motor which is significantly more powerful than the early VW's which were capable of highway speeds though barely.With autonomous automated driving vehicles there is no need for extreme speeds.55 or 60 mph will do.
Again a lot of the answer lies with overall vehicle weight.
January 15, 2012 3:03:16 PM

Unfortunately a direct conversion of hp to kw doesn't work when factoring electric motors. The first issue is a motor rarely will get 90% efficiency, I usually see high 80s. Also if a transformer were in the series as well then that is another power loss, usually around 90% efficient. Then there is the whole motor starting scenario. I've seen 100hp motors on pump jacks pull down a 230kw genset when starting. The inrush when starting a motor is huge. Thinking of this possibly some small batteries and a couple capacitors might help the start issue but again it's more weight. I think looking at around 60kw of power needs for a car would be a reasonable estimate.
January 18, 2012 8:13:06 AM

Sorry that I didn't respond sooner.I had some events to go to/other things to take care of.You're right about that very few electric motors will reach 90% efficiency.One example is in ElectraFlyer electric aircraft or in some electric bicycle motors.Even the upper 80% is pretty good.
With high current peak loads it will likely had to be a battery (probably lithium ion) with not great AH ratings but rather a very high C (charge/discharge multiplication factor) rating on the batteries the higher the rating the better.
It's looking like some batteries would have to be used though far less than current electric vehicles.In other words just at times for peak loads.
Of course if the vehicle had a much smaller Horsepower motor like the original Kdf wagen-original Volkswagen Beetle (which was probably energy equivalent to around 18.75 Kilowatt/hrs roughly) it wouldn't be needed.There are peak loads even for DC motors too.

Perhaps WiTricity could come out with a more powerful magnetic resonance transmitter more than the 3.3 KW EV charging kit.If some big corporation/government requested such an item on a large scale I am sure they would work on it as it would be in their direct Interest to do so especially because when implemented it likely would be a costly trillion dollar? infrastructure long term and scope type project with transportation.
January 18, 2012 11:51:04 PM

Well I think together we have a decent idea of how it should work. The car end wouldn't be hard to make it's just the transfer of the power that's the tough one. I hate the fact that you started this thread because I already have to many ideas of things I want to do. Now I have one more thing to lose time on.
a b F Wireless
January 31, 2012 10:59:03 PM

wip99gt said:
But by being converting on the car side by a step up transformer you'll be losing more efficiency and adding weight. A 100kw step up transformer has got to be 400+ lbs. If it is able to send a usable voltage to the car it would be tremendously better. I got to talk to one of my electricians about this and see what his ideas are with this.

You are assuming 60Hz AC power, but using a higher frequency allows a much smaller transformer. If our switching power supplies in our PCs used a 60Hz transformer they would be several times larger than they are now.
February 1, 2012 11:20:01 PM

Good point with using a higher hertz. Using something like the 400hz used on some offshore platforms would lower the transformer weight. I think that if you could just transfer a usable voltage as a whole it would still be better. Less weight and less power loss. You'd just need to find a 2000v 400hz electric motor.
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