Europe: Future Charging for Model S 1-phase or 3-phase? (Part 2)

[widodh]

No, you won't be using a Mennekes "end piece" with the UMC as the Mennekes posts already have the EVSE built in. The UMC is not needed in this scenario, just a simple cable.

I expect Tesla to use a redesigned version of their own connector on the car. And with that you'll get:

- One Mennekes-Tesla cable (simple cable since EVSE is not needed)
- One UMC with Tesla connector at one end and several possible adapters on the other end
- One adapter of your choice

The available adapters would probably be:

- Schuko 16A 230V single phase (3.7KW)
- red CEE 16A 400V three phase (11kW)
- red CEE 32A 400V three phase (22kW)
- blue CEE 16A 230V single phase (3.7kW)
- blue CEE 32A 230V single phase (7.4kW)
- blue CEE 16A 230V three phase (if 230V IT is supported) (6.3kW)
- blue CEE 32A 230V three phase (if 230V IT is supported) (12.5kW)

For those "adapters" you still need a UMC, you can't plug the Model S directly into a Red or Blue CEE since it won't be able to see how much power it can draw.

There has to be a UMC which is essentially a mobile EVSE.

At one point Tesla were considering a Mennekes pigtail for the UMC, until I told them it was pointless.

That's a pretty good list but in addition to Schuko (actually the similar CEE 7/7 which has the earth pin hole for France) you would also want pigtails for:

- UK/Ireland 13A
- Italy 16A
- Italy 10A
- Swiss 10A
- Swiss 16A
- Danish 10A

Maybe the Dutch/German 25A and 16A Perilex three phase plugs too (increasingly rare though)

The perilex connector is gone. It's ONLY used in fixed installations in kitchens when induction cooking is used (like I do at home).

In any other place you'll find the Red CEE connector.

So a 3-phase capable UMC for the EU with different pigtails would be great!

 

[dpeilow]

Also worth noting that Red CEE three phase plugs come in 4 pin (Delta) and 5 pin (Y) versions. You'd definitely want both options.

To make matters worse, I found that the Irish Sea ferry I tried to connect the Roadster up to two years ago had 5 pin outlets, but with the neutral not connected! I wonder if this is standard for reefer (refrigerated) trailers which are supposed to connect to those outlets?

 

[Johan]

- red CEE 16A 400V three phase (11kW)
- red CEE 32A 400V three phase (22kW)
- blue CEE 16A 230V single phase (3.7kW)
- blue CEE 32A 230V single phase (7.4kW)
- blue CEE 16A 230V three phase (if 230V IT is supported) (6.3kW)
- blue CEE 32A 230V three phase (if 230V IT is supported) (12.5kW)

Forgive my ignorance, but why would you need different plugs for the same current but 1P or 3P? If the CEE plug is only hooked up to 1P and the cars tries to draw on 3 phases there will only be power coming through on one of the legs, hence that's what the car gets. If you for some reason would like to draw only 1P from a plug that is hooked up to 3P then this may be possible to set in the software (same as reducing amperage)?

 

[jkirkebo]

Forgive my ignorance, but why would you need different plugs for the same current but 1P or 3P? If the CEE plug is only hooked up to 1P and the cars tries to draw on 3 phases there will only be power coming through on one of the legs, hence that's what the car gets. If you for some reason would like to draw only 1P from a plug that is hooked up to 3P then this may be possible to set in the software (same as reducing amperage)?

Because the single phase plugs exist. They have 3 pins instead of 4 or 5 for the two three phase versions (with or without Neutral). So if we want to use them, the right adapter is needed.

http://images1.hellotrade.com/data2/RK/KT/MY-2628109/113_123-250x250.jpg

Three phase sockets hooked up to just a single phase would be no good, imagine trying to hook up some three phase equiment to one.

 

[eledille]

Note that the E and F sockets both use the same plug (CEE 7/7, as dpeilow wrote).

 

[eledille]

Can't the two chargers be in parallell, on all three legs symmetrically? In effect each charger being a 3x3.3 kW unit?

Yes, you can connect two 3P chargers to the grid in parallel. However, each charger is hopefully not a 3x3.3 kW, but rather an 11 kW three phase unit (16 A)

I suspect Tesla has realized that there will be lots of 22 kW charge points available in Europe, and that they have made a single 22 kW three phase unit instead of two 11 kW units that can be combined to 22 kW. That would cost more, and if they use all the available space from the two US single phase units, they ought to have enough space for much more than 20 kW. Maybe even 43 kW.

400 V three phase is not simply three 230 V single phase connections.

This is a single phase diode bridge rectifier:

It requires four diodes.

This is a three phase diode bridge rectifier:

It requires six diodes - only 50% more than the single phase variant. If you were to build three separate single phase rectifiers to utilize that three phase connection, you would need 12 diodes - twice as many as are actually required.

The single phase diode bridge produces the following output (blue curve - the low points are at zero voltage):

The three phase diode bridge produces the following output (lower curve - note small difference between low and high output voltage):

The output from the three phase bridge is very much easier to smooth into a flat DC, which is what the battery wants. The smoothing is the tricky bit - when really high power DC is needed, 3 to 12 phase transformers are sometimes used just because the smoothing gets easier the more phases you have. Also, you have to do power factor correction - when you try to smooth something very bumpy, like the output from a single phase diode bridge, you end up pulling current when the voltage is low instead of high. The power company strongly dislikes that, so you have to install extra equipment to correct it.

You really want a proper three phase charger, not combinations of single phase units.

 

[widodh]

Yes, you can connect two 3P chargers to the grid in parallel. However, each charger is hopefully not a 3x3.3 kW, but rather an 11 kW three phase unit (16 A)

I suspect Tesla has realized that there will be lots of 22 kW charge points available in Europe, and that they have made a single 22 kW three phase unit instead of two 11 kW units that can be combined to 22 kW. That would cost more, and if they use all the available space from the two US single phase units, they ought to have enough space for much more than 20 kW. Maybe even 43 kW.

Like Eberhard always posted: BRUSA: NLG6, Fast Charger

That charger does 22kW and weighs just 12kg! Does 16A 1-phase and 32A 3-phase. So not ideal for the UK where they also want high single-phase charging.

 

[jkirkebo]

That charger does 22kW and weighs just 12kg! Does 16A 1-phase and 32A 3-phase. So not ideal for the UK where they also want high single-phase charging.

Yeah, any solution not capable of 32A single phase charging is no good for Norway either.

 

[eledille]

Yeah, any solution not capable of 32A single phase charging is no good for Norway either.

"No good" seems a stretch? Or are there many cabins that only have single phase?

 

[jkirkebo]

"No good" seems a stretch? Or are there many cabins that only have single phase?

There is quite a few houses here without three phase service. Those would be restricted to 16A without 32A single phase compatibility. For example my parents house have single phase 50A service.
Also if 230V IT three phase is not supported, then most others would be restricted to 16A too.

There is also a few 25A sockets to be found if needed (mostly inside, for stoves) and some 32A single phase ones outside. Nice to have access to on roadtrips.

 

[Bipo]

Here in Spain most houses only get one-phase 230 V and the most common limit is 25 A. That limit is not set by a physical limit on the wires, but for our utilities's price-per-kW policy.

Here you must pay each month 1,82 € per kW of peak power you get from the grid. So the average home (25 A -> 5.75 kW) pays 10 € each month even if they don't turn on the light. Then you must add 0.15 € per kWh of energy, plus taxes (+ 25%).

If you get more than 10 kW of peak power (and less than 20 kW), you will pay higher prices: 2.19 €/kW monthly (10-20 kW) and 0.175 €/kWh, plus taxes (+ 25%).

Over 20 kW is assumed only for industrial purposes, so you must get another type of contract.


Anyway, three-phase supply reach every building, and there is no problem if you contact your utility to get three-phase at home. The only problem is the increase of prices... You pay quite a lot only to get access to "high" power.

 

[VolkerP]

[...]
This is a three phase diode bridge rectifier:

It requires six diodes - only 50% more than the single phase variant. If you were to build three separate single phase rectifiers to utilize that three phase connection, you would need 12 diodes - twice as many as are actually required.

eledille I think you are late to the party. Eberhard posted in Oct 2011:

JB Straubel told me, that there is no standard bridge rectifier, they use IGBTs instead as being more efficient and allows direct power control.

 

[eledille]

eledille I think you are late to the party. Eberhard posted in Oct 2011:

Maybe I didn't start the party, but I'm certainly not late to it

I remember that post too, but exactly how Tesla is doing it does not change the physics of rectification. The diode bridge is just the easiest way to understand what's going on.

There are many rectifier topologies that don't have a diode bridge, but they all have to overcome the same basic problem: First make the electrons move in only one direction instead of back and forth, second find a way to store power during the voltage peaks to deliver during the troughs.

With or without IGBTs and diode bridges you have do do this in a way that does not send too much noise back to the supply or pull current while the input voltage is low (current and voltage waveforms out of phase, aka. poor power factor). Single phase AC has long periods of low voltage, and that makes the task harder. If you instead rectify all three phases simultaneously, then you have access to smoother voltage, which makes the task easier.

If the situation arises that three single phase rectifiers totalling 22 kW are less expensive than a single 22 kW three phase rectifier, then as far as I can understand the cause must be some other factor, for example that one is mass produced and the other is not. Even then, you will end up with twice the weight and volume.

By the way, I am of the opinion that chargers must be eliminated - by implementing them in the regenerative circuitry of the motor drive

 

[sjokomelk]

This is my first time posting here, but I have followed this thread with keen interest for some time now.

Why do we need a seperate three phase charger in the car? I thought all Model S, even the US ones, have a three phase charger already - the regen-unit from the motor. It takes three phase current from the motor, rectifies it and stores it in the battery. The motor is a 4 pole three phase motor? Why not just connect the power to this, and let the regen-unit take care of the rest? It doesn't know if the power is supplied by the motor turning or from the grid. All it sees is a 50 Hz current.

 

[qwk]

The 1.5 roadster did something similar, but Tesla must have decided it wasn't worth the patent royalties to AC Propulsion.

 

[eledille]

The 1.5 roadster did something similar, but Tesla must have decided it wasn't worth the patent royalties to AC Propulsion.

No, the Roadster used AC Propulsions patents regarding the use of the motor windings for smoothing of the seriously bumpy output from single phase rectification. That's not related to the three phase regen circuitry. I believe they also reused some components of the motor drive, so the ideas may overlap somewhat, but Renault has been able to get multiple patents from their Chameleon charger registered, so the overlap can't be complete.

 

[dpeilow]

Renault are probably doing similar.

 

[eledille]

There is quite a few houses here without three phase service. Those would be restricted to 16A without 32A single phase compatibility. For example my parents house have single phase 50A service.
Also if 230V IT three phase is not supported, then most others would be restricted to 16A too.

There is also a few 25A sockets to be found if needed (mostly inside, for stoves) and some 32A single phase ones outside. Nice to have access to on roadtrips.

The latest rumours say that 230 V IT three phase is supported, which is great if true. Even so I would be surprised if they don't support 32 A single phase as several European countries need that too. France also has a mix of single and three phase domestic service.

 

[stopcrazypp]

No, the Roadster used AC Propulsions patents regarding the use of the motor windings for smoothing of the seriously bumpy output from single phase rectification. That's not related to the three phase regen circuitry. I believe they also reused some components of the motor drive, so the ideas may overlap somewhat, but Renault has been able to get multiple patents from their Chameleon charger registered, so the overlap can't be complete.

I think Renault's patents apply in Europe. AC Propulsion's apply in the US. The idea between the two are pretty similar (besides from using the windings, AC Propulsion also reused components in the PEM for charging), but Renault's allows 3-phase charging.

If I had to pick something, I would pick patents, but I remember reading somewhere that using the windings can cause them to overheat and I guess the additional cooling load also affects efficiency. Since the EPA number measures electricity from the wall and Elon has said the efficiency of the Model S charger can still improve, I think that may also be a factor.
Here's a thread that discussed the decision to drop reductive charging in the Roadster:
http://www.teslamotorsclub.com/showthread.php/2525-Magnetic-Saturation/page3

 

[eledille]

stopcrazypp: Thanks for that link, there are multiple good links in that thread.

A patent has to be fairly specific, so there might be ways to get around them, particularly as one is three phase and the other is single phase.

One big difference between ACP's and Renault's situations is that three phase is very widespread in Renaults home market and does not require anywhere near as large inductors in the rectifier. So reusing the motor as an inductor is less important in Renault's case. If Renault also uses the motor as an inductor, then the current through it is likely to be much smaller per kW output when charging from three phase. ACP didn't have that advantage.

By the way, this link indicates that the Chameleon charger also supports single phase up to 32 A - quite good and good enough in its home market, but less than half of the reductive charger. It's just a personal blog, though, so it might be incorrect. *edit* Rereading it, it looks likely to be just speculation. Is there any definitive info on the maximum single phase power of the Chameleon charger yet?

I don't think motor winding overheating should be a problem for a liquid cooled motor. If so, the system is too inefficient anyway.