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Discussion Starter #1
HI,
I have just acuired a Renault Zoe Motor. It appears to be a synchronous motor. It has a electicaly magnitised rotor and stator with three pahse and nutral cables.

I am trying to get it to spin but I dont have any nameplate info for the motor.

If anybody has this information I would appreciate it. I havent been able to find it on the WEB.

Thanks in advance.

Andrew
 

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It appears to be a synchronous motor. It has a electicaly magnitised rotor and stator with three pahse and nutral cables.
By "electrically magnetized" do you mean that the rotor is wound and powered? That would be strange for a modern EV, and would require brushes and slip rings.

I did a quick web search, and ran across this
The R240 motor is a synchronous electric motor with rotor coil.
Images from another article seems to confirm the wound and powered rotor of this particular motor (not the only motor Renault has made):

Other images on the same page show the slip rings used to get power through the rotor.

I wondered at first if you meant that it has shorted windings, such as squirrel cage: that would make it an induction motor, not a synchronous motor, but that doesn't appear to be the case.


With three lines and a neutral, it would presumably be wye wired, which seems unusual - most 3-phase motors seem to delta wired. Some online discussions talk about using the stator windings as part of the charging circuit, presumably as a transformer for charging from an AC source; perhaps the unusual stator winding (with a neutral) was needed for the charging mode.


With both a powered rotor and wye-wired stator, my guess is that the only practical way to drive this motor would be with the original equipment inverter-controller. Unfortunately, I have no information about working with this hardware.
 

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Discussion Starter #3
Hi Brian,

Yes the rotor looks like that. I have shorted the rotor cables together at the moment. So it will act a bit like an induction motor. Maybe.

If i dont short the dc rotor cables and don't put any voltage on them it acts a bit like a transformer and ac voltage is generated and there is no rotation.

In theory i just need to provide enough current to magnitise the rotor?

Also I was hoping that the nutral cable could be left out insulated and i could just use the 3 phase cables.

I cant find any OEM inverters for these for sale and I probably wouldnt
be able to control it if I had one.

I am currently trying to guess the specifications by entering parameters into a small industrial VSD.

If anyone has any better ideas I am interested.

Thanks

Andrew
 

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Yes the rotor looks like that. I have shorted the rotor cables together at the moment. So it will act a bit like an induction motor. Maybe.
It's only a guess, but I doubt with the number of turns in the rotor windings and their resistance that there would be enough induced current to work well as an induction rotor. For that possibility, you need someone who has more experience in this area than I have, or at least has put more thought into it.

If i dont short the dc rotor cables and don't put any voltage on them it acts a bit like a transformer and ac voltage is generated and there is no rotation.
Right, because that's all it is... the rotor windings don't do anything useful, and the stationary rotor laminations are not effective enough to make it act as a synchronous reluctance motor.

In theory i just need to provide enough current to magnitise the rotor?
Yes, with AC power to the stator, and slip rings connecting the rotor winding, I assume that you need to provide a DC current for the rotor field. This will be like a shunt-wired stator winding in a brushed DC motor, which is typically called a "separately excited" or "SepEx" configuration in this forum. While there are controllers for SepEx motors - with a separate output for the field winding - they are for DC motors, so they would not be useful in this case.

I expect that the Renault controller provides only as much current to the rotor as is needed to maintain synchronous operation (which means increasing rotor current when the stator current is increased), and may reduce rotor current at high speed (to reduce the stator voltage needed to overcome back EMF).

Perhaps you could use a small DC controller, intended for a much smaller series-wound brushed DC motor, programmed for a suitable constant current, or controlling current in response to the same input (typically treated as a torque request) as the main controller?

Also I was hoping that the nutral cable could be left out insulated and i could just use the 3 phase cables.
Really just guessing here, but if the variable speed drive can handle a wye connection without using the neutral, then I suppose that should work. I have heard that it is common to power wye-wired systems with the neutral isolated, although perhaps not with motors. Again, we need someone with more relevant experience here.
 

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By "electrically magnetized" do you mean that the rotor is wound and powered? That would be strange for a modern EV, and would require brushes and slip rings.
Very strange. The field power takes away from motor efficiency, and this motor is purported to extend range some 15% (from 210 km to 240 km).

My only suggestion is that they do this so that they can do field weakening more easily or aggressively. Perhaps it's more efficient than a permanent magnet motor when field weakening, and perhaps they feel that this is the more important motor speed region.

Or perhaps they are worried about the life of the usual permanent magnets. Or the cost and continued ability to source the rare earth materials required, and the extra efficiency comes from elsewhere. Maybe the hassle of assembling a motor with permanent magnets is worth the cost of the rotor and brushes.

Cynically: perhaps they want something to wear out and be replaced in regular services (the brushes).
 

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From NZ EV Wiki: The Zoe Charger
The Zoe’s charging system is called the Chameleon charger. It uses the motor windings as part of the charging system, and an inherent features of this design is that it can charge off three phase AC. Three phase is common in many parts of the world, including Europe and NZ (but not in the USA).
My interpretation of this is that 3-phase power without a neutral is fed to the motor's stator winding, then three separate single-phase AC circuits are taken off of that (each between a phase conductor and the neutral) to run three parallel AC-to-DC chargers; that would require the neutral and a wye-wired stator.

If this is the only reason for the wye stator wiring, then feeding it 3-phase power without the neutral connected makes sense. It would be nice to know if the Renault inverter (not the charger) uses the neutral connection. Since the the three phases are balanced (unlike many three-phase power systems with connected single-phase loads), there isn't an obvious need for the neutral.
 

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Very strange. The field power takes away from motor efficiency, and this motor is purported to extend range some 15% (from 210 km to 240 km).
The range improvement is relative the original motor, which was made by Continental and referred to by Renault as the Q210. Was the Q210 PM, or did it have a wound rotor too? Continental (if I have the right company) does make wound-rotor motors, although they are much larger than the ZOE would use and Continental describes them as "induction" motors. :confused:

Cynically: perhaps they want something to wear out and be replaced in regular services (the brushes).
:D
... but brush wear shouldn't be bad, with only plain slip rings and not a segmented commutator.
 

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Discussion Starter #8
Thanks Brian. That's good information on the 3 phase charging and now we know why there is a neutral connection.

I was thinking if I connect another motor to it and rotate it at different speeds and supply a voltage to the rotor. I then would be able to measure the back emf to work out the voltage hz ratio?

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Although I initially said this:
My interpretation of this is that 3-phase power without a neutral is fed to the motor's stator winding, then three separate single-phase AC circuits are taken off of that (each between a phase conductor and the neutral) to run three parallel AC-to-DC chargers; that would require the neutral and a wye-wired stator.
but then I was thinking about this:
If i dont short the dc rotor cables and don't put any voltage on them it acts a bit like a transformer and ac voltage is generated and there is no rotation.
So I'm wondering they charge from a 3-phase supply by powering the stator and taking single-phase AC power for the on-board charger from the rotor winding. In that case, the wye wiring may only be to match the supply voltage, and the neutral connection might not be needed even for charging.

Anyway, this doesn't really matter to using the motor as a motor.
 

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Discussion Starter #10
That's an interesting thought. But it could damage the slip rings if the rotor is not rotating. So I think you were right first time.

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Hello.

Did this stop already? I live in France where there are suddenly a lot of these things around, they're not the most exciting, but could be the most cost effective, simple and compact with their integrated output diff. It's a nice simple package for front rear or indeed four wheel drive.

Does anybody know of anybody working on this, or who may be interested in it? I am an experiences project car builder and I know a bit about this and that, but I don't have anything like the specialist motor understanding I see around here...

As always, any help / guidance much appreciated. 😓
 

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Sprocketman

did you ever get the zoe motor to spin ?
 
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