3.2kW wireless EV charger, uhhhhhhh

[apis]

There is no exotic technology used in that paper, the components are similar to those that you would find in a typical off-the-shelf high power battery charger.

Sounds interesting, too bad it's behind a paywall.

A wired DC charger would typically ...

Still think it's meaningless to compare a state of the art, lab prototype, wireless charger with a typical wired charger.

You should compare that to the efficiency of a state of the art, lab prototype, wired charger...

[CopperCone]

I want to embed it in the floor. No more gas station. I hate gas stations so nuch i thought to get a burried petrol tank. They are a pain in the ass.

[Wolfram]

Still think it's meaningless to compare a state of the art, lab prototype, wireless charger with a typical wired charger.

You should compare that to the efficiency of a state of the art, lab prototype, wired charger...

That's a fair point, though I think "meaningless" is a strong word here. The comparison can still be meaningful as this demonstration is based on the same generation of power components as typical wired chargers. Charger topologies have advanced to a point where the performance is limited by the available components and not by the technology. Any advance that will benefit wired chargers, such as wide band-gap semiconductors, will also benefit wireless ones similarly.

To do a comparison with a state-of-the-art lab prototype wired charger is easy, as I have one running here, built around wide band-gap semiconductors (SiC MOSFETs). We get an efficiency of around 98.6 % on the AC-DC conversion (400 V three-phase to 750 V DC) and an efficiency of just over 98 % on the isolated DC/DC converter. The wireless technology would in other words incur additional losses of around two percent of the processed power. In many cases, the increased convenience of wireless charging can justify these additional losses. Also consider the fact that these additional losses could be reduced using the wide band-gap semiconductor technology that is used in our prototype charger.

[Mr. Scram]

. . .which is cool, but still a far less elegant solution than the wireless charging pad.  It requires a whole mechanical arrangement, a whole vision system for alignment, it's bulky and prone to getting driven into, etc.  Whereas the wireless pad needs no moving parts and at most relies on the sensor suite that's already built into the car anyway.

No moving parts and physics that outright prohibit any reasonable efficiency. That's not elegant by a long shot.

[Mr. Scram]

I would rather get an rf bite then touch 400vdc. Rf will just burn you while dc will remove a limb.
Think that its great.

Embedding some kind of badass rf transmitter in the garage floor would be epic. 95% efficency is great.

I don't know whether you habitually electrocuted yourself as a child or something, but you're overestimating the likelihood of "getting zapped" by a properly designed cabled charging system to a degree that it sounds like a phobia. It has nothing to do with real world problems and the associated engineering challenges.

Cables are safe. Untrained and idiotic people use cheap and substandard cables on a massive scale on a daily basis without it being eventful. We're not even talking about how we have more than a century of experience with cables in home settings, while we basically have none when it comes to large scale wireless chargers in a home setting.

[james_s]

I'm starting to think he has some kind of financial interest in the wireless charging solution, or is just trolling. I mean seriously, doesn't like to handle power cords? Has considered getting a buried petrol tank at home to avoid going to gas stations? What nonsense.

[Mr. Scram]

I want to embed it in the floor. No more gas station. I hate gas stations so nuch i thought to get a burried petrol tank. They are a pain in the ass.

Hold on. You consider cables to be death traps but are prepared to live on top of a tank of petrol?

[CopperCone]

nah I would put it out back a hundred feet away from where I 'live' to make a private gas station 

If it was nonsense then it would not be being developed and wireless phone chargers would not be common place. You are just a dinosaur.

[tszaboo]

85% efficiency... so 15% of 3.2kW which is 480W gets wasted as... heat?

Hans also has a solar panel on the top of his house. 480W gets wasted. energy in that is about the same energy that the device would receive in direct sunlight.
I dont know why people get upset by the efficiency, while most people are driving a "19 century tractor" with 25-is% efficiency, and they dont even have regen breaking.

[Red Squirrel]

Bonus is if you have any metal plates in your body you can walk on the inductive pad and they will warm you up fast from the induction!

[james_s]

Nonsense products are developed all the time, probably 10:1 vs stuff that actually works well and makes sense. Need I mention the infamous Batteriser thread? There are numerous other examples on the forum. Me I'm interested in maximizing energy efficiency. If that favored wireless transfer I'd be all for it but an old fashioned cord has a significant advantage there and very few valid disadvantages. Lower cost to purchase, lower cost of operation, less to go wrong, less EMI, if that's not important to you then go ahead and install a wireless gadget, the rest of us will stick to wires because they make more sense to a rational person.

[Mr. Scram]

nah I would put it out back a hundred feet away from where I 'live' to make a private gas station 

If it was nonsense then it would not be being developed and wireless phone chargers would not be common place. You are just a dinosaur.

Lazy trolls are the worst. Ones that can muster some clever responses are much more amusing.

[CopperCone]

is something above plugging it into the wall too complicated for you??

[Mr. Scram]

is something above plugging it into the wall too complicated for you??

At least I can manage plugging something in. 

[Red Squirrel]

Actually I just had an idea, EV cars should have a standard plug type that you can drive into, maybe near the wheel, so there would be a small ramp (like car washes) to guide the car into the plug.  Of course it would need various bumpers and guides to protect itself from bad drivers. I'm thinking the actual plug/probes would only extend once it's in the proper position.  Make this a standard and it could be installed in driveways, parking lots, etc.  I'm thinking the plug would come from the ground and connect upwards into the car, as it would make it so you can drive over it completely no problem, ex: in a driveway you would maybe install two back to back so first car drives over the first one and other car drives behind.   This would not replace a cord as not every place would have this, but the idea is it would make for a quick and easy way to get a charge without physically plugging anything.  Big power cords can be cumbersome especially in -40's as even regular 14/2 extension can get quite stiff for plugging in the block heater.

The power cord plug should be standardized too though, I foresee an issue with electric cars where everyone wants to patent everything and there will never be a standard charging station/plug type.   It should be like gas pumps, where you can go to any charge station and charge.

[vk6zgo]

Its quite safe if it works. The problem is still that you need to handle a high voltage conductor that can malfunction and it can be cut, insulation can go bad, control systems malfunction, etc.

If it was in a industrial setting they would probably check it with a fucking megger periodically. To do it right you probobly need to disable it with contactors (rather then relying on a software safety to depower a H-bridge or something). This means electromechanical parts, which means ware and tear, inspection requirements, etc.

I have never handled ev-charing cables, but they look like they are reinforced PUR cables. PUR cables are almost indestructible, but expensive. The next best thing is rubber cable, this is also very solid cable, but eventually will get cuts and damages. Rubber cables are used in industrial setting when the cables are temporary. Rubber cables are indeed regularly tested to spec. The insulation is rarely at fault, is it would you could see it with visual inspection, mostly the contact resistance on the plugs fails spec.

PVC cables are toys compared to rubber or PUR.

You don't need a physical disconnect, there are online insulation monitors.

Funny that, the three phase cables used to connect transportable diesel driven alternators ( commonly used in TV OBs) to their load use reinforced PVC.

Those transportable alternators are big units---- we used one to provide standby power to a TV Transmitter site with a 13kW TV transmitter & two 5kW FM transmitters.
They weren't marginal, either, we could run the standby transmitters on test at the same time.
All connected with a "toy" PVC cable!

[james_s]

I don't know what the material is but I've handled the charging cords on one of my friends' EV and it's one of those rubbery feeling cables like the power cords on the machine tools in their shop, feels like it's probably 10AWG. It's durable enough to be dragged around on the driveway and has been driven over a few times with no signs of deterioration so far after a couple years. It's heavier and bulkier than the typical outdoor extension cord you'd use to power a string trimmer or power saw but it's lighter and more flexible than a garden hose. The charger is a surprisingly small box inline in the cord which plugs into a 30A 240V socket of the sort used by older clothes dryers. I suspect most of the charging electronics are integrated into the car and the external box is mostly a safety cutout. The connector that plugs into the car is nicely designed and includes a tethered rubber cap that can be put on if you want to leave the cord outside in the driveway.

[apis]

Actually I just had an idea, EV cars should have a standard plug type that you can drive into, maybe near the wheel, so there would be a small ramp (like car washes) to guide the car into the plug.  Of course it would need various bumpers and guides to protect itself from bad drivers. I'm thinking the actual plug/probes would only extend once it's in the proper position.  Make this a standard and it could be installed in driveways, parking lots, etc.  I'm thinking the plug would come from the ground and connect upwards into the car, as it would make it so you can drive over it completely no problem, ex: in a driveway you would maybe install two back to back so first car drives over the first one and other car drives behind.   This would not replace a cord as not every place would have this, but the idea is it would make for a quick and easy way to get a charge without physically plugging anything.  Big power cords can be cumbersome especially in -40's as even regular 14/2 extension can get quite stiff for plugging in the block heater.

The power cord plug should be standardized too though, I foresee an issue with electric cars where everyone wants to patent everything and there will never be a standard charging station/plug type.   It should be like gas pumps, where you can go to any charge station and charge.

Good idea. If the batteries are standardised too and they could be automatically replaced from below the car, you could have gas stations battery stations where you drive onto a ramp and the battery is replaced with a freshly charged one automatically. That way the range problem would more or less disappear, it would be the same as refueling a car with an internal combustion engine.

[james_s]

This idea has been thought of, but there are various problems with it.

It has been hashed out already in multiple threads, but the real solution for the range "problem" is to move beyond the filling station mentality and use EVs where they currently make the most sense, as short to medium range commuter cars that you charge either overnight in your driveway or garage, or during the day while parked at work. With this workflow there is no need to try to charge as quickly as you'd fill a tank with liquid fuel, rather than run until empty and then fill up you simply plug in the car like you plug in your mobile phone and it's always ready to go. For people who need to drive longer distances or don't have this as a reasonable option, internal combustion, hybrids and plug-in hybrids may be a better fit. There are many millions of cars out there that are exclusively used for commuting and running errands where long range is not a requirement, and that is the use case that EVs are ideally suited for. ICE is not going away any time soon, we don't need to try to replace it completely.

[Mr. Scram]

This idea has been thought of, but there are various problems with it.

It has been hashed out already in multiple threads, but the real solution for the range "problem" is to move beyond the filling station mentality and use EVs where they currently make the most sense, as short to medium range commuter cars that you charge either overnight in your driveway or garage, or during the day while parked at work. With this workflow there is no need to try to charge as quickly as you'd fill a tank with liquid fuel, rather than run until empty and then fill up you simply plug in the car like you plug in your mobile phone and it's always ready to go. For people who need to drive longer distances or don't have this as a reasonable option, internal combustion, hybrids and plug-in hybrids may be a better fit. There are many millions of cars out there that are exclusively used for commuting and running errands where long range is not a requirement, and that is the use case that EVs are ideally suited for. ICE is not going away any time soon, we don't need to try to replace it completely.

Without the EV being up to the level of the filling station it's never going to become the dominant technology. There's one thing that technology has to do to make it and that's not being a lot more terrible than whatever it replaces. We can make do for short range commuting, but the issue really needs to be addressed in full.

[james_s]

Without the EV being up to the level of the filling station it's never going to become the dominant technology. There's one thing that technology has to do to make it and that's not being a lot more terrible than whatever it replaces. We can make do for short range commuting, but the issue really needs to be addressed in full.

Trying to emulate an existing technology can prevent something from ever advancing. I see EVs every day around here, they're all over the place and more are appearing all the time. Off the top of my head I can think of at least 5 people I know that have them and the whole never having to go to a gas station to fill up, just plug the thing in every night is the number one feature they all rave about. The car is ready to go every morning, with more than enough range for the trip to work and back and some errands around town, never even a thought about "filling up", it's just always ready. I know people hate change, but this is one of those changes where the only people who complain about it are the people who have never tried it. Some people do regularly need longer range, EVs are not for them, that's why other technologies exist which can fill their needs.

[nctnico]

This idea has been thought of, but there are various problems with it.

It has been hashed out already in multiple threads, but the real solution for the range "problem" is to move beyond the filling station mentality and use EVs where they currently make the most sense, as short to medium range commuter cars that you charge either overnight in your driveway or garage, or during the day while parked at work.

The latter will be expensive because you'll probably pay extra for the electricity due to the extra charging infrastructure in the parking garage. The first isn't an option for all people because many people don't have drive ways. And even if people have a drive way the residential grid isn't designed for charging loads of EVs so again: you'll pay extra for upgrading the residential grid. Having centralised charging points with very fast chargers will prove to be more economical because there is a more effective sharing of infrastructure. With slow charging you need one or even two chargers for each EV and guess who is going to pay for those. With fast charging you need only one charger for thousands of EVs. So even if the fast charger costs $100k to install the cost per EV owner will be a few tens of dollars.

[Mr. Scram]

Trying to emulate an existing technology can prevent something from ever advancing. I see EVs every day around here, they're all over the place and more are appearing all the time. Off the top of my head I can think of at least 5 people I know that have them and the whole never having to go to a gas station to fill up, just plug the thing in every night is the number one feature they all rave about. The car is ready to go every morning, with more than enough range for the trip to work and back and some errands around town, never even a thought about "filling up", it's just always ready. I know people hate change, but this is one of those changes where the only people who complain about it are the people who have never tried it. Some people do regularly need longer range, EVs are not for them, that's why other technologies exist which can fill their needs.

It's not about resisting change, it's about resisting a significant disadvantage in a relevant portion of the use cases.

Though I feel people are also unrealistically optimistic or pessimistic about the gains or losses. Personally I don't feel plugging in a car every night is more convenient than going to a gas station for 5 minutes once a week. It's not a huge hassle to plug a car in either. The financial benefits may be attractive, though I also imagine it having to do with one being explicit bills and the other being absorbed into a much larger bill. Concert venues make use of the same trick when they sell tokens or punch cards to people. The actual cost of what's being spent isn't so obvious, so people more easily spend the money. That's why I'm going to take both raving and ranting people with a grain of salt. The raving folks just spent a huge amount of money on something and are very invested in it being better. Ranting folks regularly just want to shit on things.

Don't get me wrong, I'm anything but anti EV. It's obviously the way forward and viable in a lot of cases already, but to actually take the place of traditional cars some problems still need to get solved. Or they need to artificially disadvantage traditional cars by levying taxes or something of course, but that's not going to fix the limitation.

[NiHaoMike]

And even if people have a drive way the residential grid isn't designed for charging loads of EVs so again: you'll pay extra for upgrading the residential grid.

Most EV charging is at night, which is off peak. The addition is also gradual, giving a lot of time for adaptation.

[JohnnyMalaria]

never even a thought about "filling up", it's just always ready.

And the same people don't give a thought about how the electricity was actually generated to charge their Pious Prius cars. They don't give a thought to the fact that a typical car requires the energy equivalent to 50,000 gallons of gas/petrol to make from the raw materials and so the environmenally friendly (what a bullshit term that is) vehicle they just bought brand new is contributing more to environmental damage than the 10 year old car they sold.