ELECTRIC TRANSMISSION DELTA /WYE and SERIE/PAPALLEL stator

[Doctorbass]

I just comeback from my last ride.

I spend 10Ah at 48V and the mean power was around 1600W continuous and the Nine contient can hold that no priblem with outdoor temp of 6 celsius... The case of the motor is to around 35 degree C.

Comparing the powerband of the delta and star mode i conclude that this is very different!!

-The STAR mode have a very narrow powerband.. maybe from 0 to 20km/h

-The DELTA mode have a wider powerband from 15 to 50km/h

All test were done at 48V.

that would be amazing to do that on 90-100V !!!

and i just can't imagine with a 5305 !!! One word: INCREDIBLE !

Doc

 

[Doctorbass]

Here is a reminder of the wiring configuration for those who still had not see it:


(the good news is that my controller still have no problem with the change between one mode to another.. it appear that the voltage spikes are not too damadgeable for it... I also accidentally switched while the throttle was WOT at 40A and it still work nice!..

Probably that at 75 or 100V the mosfet would have not liked that but i had not tried it yet on road :wink:

Doc

 

[Almasi]

Comparing the powerband of the delta and star mode i conclude that this is very different!!

-The STAR mode have a very narrow powerband.. maybe from 0 to 20km/h

-The DELTA mode have a wider powerband from 15 to 50km/h


Doc

Is the efficiency different in Star VS Delta mode ? It would be great to see that comparaison (same speed with Delta VS Star)

If it's almost the same...then why are hub motor made with start instead of delta (just for the start torque maybe?)

Robin

 

[Doctorbass]

Comparing the powerband of the delta and star mode i conclude that this is very different!!

-The STAR mode have a very narrow powerband.. maybe from 0 to 20km/h

-The DELTA mode have a wider powerband from 15 to 50km/h


Doc

Is the efficiency different in Star VS Delta mode ? It would be great to see that comparaison (same speed with Delta VS Star)

If it's almost the same...then why are hub motor made with start instead of delta (just for the start torque maybe?)

Robin

The Star mode induce less noise and is a bit more efficient. The reason i've read is that with DELTA, when the current goes to one phase (direct across one phase winding, it also induce current to the two other phase that appear in serie and not exactly in the same phase than it.. so it'S a little short on the two other phases.

Hrer is an explanation i did for you: (see the pic)



Doc

 

[Doctorbass]

Here is a cuircuit that i found that control the relay... it is made for a windmill

It automaticly switch at a certain RPM !!

http://www.dsgnspec.com/StarDelta.html

http://www.dsgnspec.com/Star-Delta.jpg



Doc

 

[dnmun]

looks great. how large?

will they fit inside the hub? i assume the single lug on top is the common?

30A is more than enuff, really great find, maybe there are more similar relays which may work. if they get small enuff to fit inside the hub, this would be so much simpler.

maybe epoxy them to the surface of the stator and you have plenty of room for large gauge cable through the opening along with the coil current and hall sensor wires.

 

[Doctorbass]

Here is a quick test i did this afternoon.. not as conclusive as it could do (i was limited by the lenght of the street and not reached the max speed on delta mode to show the 1.73 ratio.. and only at 48V 900W avg 1700W peak but in few hours i'll post another.. it's night here now so it woill be a little bit darker..

Here is the video Star 35kph vs Delta 45kph short road path test:
[youtube]VboRceBoJYw[/youtube]

Doc

 

[karma]

nice test how manny amps?

 

[Doctorbass]

nice test how manny amps?

In this test the max amp was 37A

But in the test i did 10 minutes ago at 65V it reached 56A and 2900W ... in a nine continent motor !!! and 1950W avg on all the ride i did with 625Wh used

Max speed at fresh charged battery on flat 56km/h in Star mode and .... 83km/h in delta mode

i'll post the next video in few minutes

Doc

 

[karma]

well my new controller's a virgin i think its time to mod. just looking at your video delta works well with higher amps

 

[Almasi]

Comparing the powerband of the delta and star mode i conclude that this is very different!!

-The STAR mode have a very narrow powerband.. maybe from 0 to 20km/h

-The DELTA mode have a wider powerband from 15 to 50km/h


Doc

Is the efficiency different in Star VS Delta mode ? It would be great to see that comparaison (same speed with Delta VS Star)

If it's almost the same...then why are hub motor made with start instead of delta (just for the start torque maybe?)

Robin

The Star mode induce less noise and is a bit more efficient. The reason i've read is that with DELTA, when the current goes to one phase (direct across one phase winding, it also induce current to the two other phase that appear in serie and not exactly in the same phase than it.. so it'S a little short on the two other phases.

Hrer is an explanation i did for you: (see the pic)



Doc

The fix for that would be a new controller with 6 output...it would do all this (DELTA / STAR) but with the efficiency of STAR no? sound like a great idea...or maybe I smoked too much

Robin

 

[Doctorbass]

The fix for that would be a new controller with 6 output...it would do all this (DELTA / STAR) but with the efficiency of STAR no? sound like a great idea...or maybe I smoked too much

Robin

You did not smoked too much.. (but should stop smking anyway for your health )

ZapPat is working on a controller desing that would do that !

Doc

 

[Almasi]

The fix for that would be a new controller with 6 output...it would do all this (DELTA / STAR) but with the efficiency of STAR no? sound like a great idea...or maybe I smoked too much

Robin

You did not smoked too much.. (but should stop smking anyway for your health )

ZapPat is working on a controller desing that would do that !

Doc

Maybe I wasn't clear.... if we don't attach the wire is series in DELTA, but leave them 'isolated' and drive them the way we should, without having that 'parasit' current flowing in the other coil....or would that be a bad idea?

Robin

 

[Doctorbass]

The fix for that would be a new controller with 6 output...it would do all this (DELTA / STAR) but with the efficiency of STAR no? sound like a great idea...or maybe I smoked too much

Robin

You did not smoked too much.. (but should stop smking anyway for your health )

ZapPat is working on a controller desing that would do that !

Doc

Maybe I wasn't clear.... if we don't attach the wire is series in DELTA, but leave them 'isolated' and drive them the way we should, without having that 'parasit' current flowing in the other coil....or would that be a bad idea?

Robin

This is not possible Robin, cause the current that goes to every phase is provided by the same battery for the low side fet nd the high fet side .. it's like every phase are supplyed bty the same parallel current but not at the same time... (120 degree offset each)

To do what you suggest you would need 3 independent current source... so 3 independent battery ! :|

Doc

 

[Almasi]

This is not possible Robin, cause the current that goes to every phase is provided by the same battery for the low side fet nd the high fet side .. it's like every phase are supplyed bty the same parallel current but not at the same time... (120 degree offset each)

To do what you suggest you would need 3 independent current source... so 3 independent battery ! :|

Doc

Or 3 big DC to DC converter...or just battery pack spit in 3....ok, it does actually sound more complicated ....

So any idea how less efficient the system is when you run in DELTA Vs STAR ? (10, 20% more???)

Robin

 

[Doctorbass]

This is not possible Robin, cause the current that goes to every phase is provided by the same battery for the low side fet nd the high fet side .. it's like every phase are supplyed bty the same parallel current but not at the same time... (120 degree offset each)

To do what you suggest you would need 3 independent current source... so 3 independent battery ! :|

Doc

Or 3 big DC to DC converter...or just battery pack spit in 3....ok, it does actually sound more complicated ....

So any idea how less efficient the system is when you run in DELTA Vs STAR ? (10, 20% more???)

Robin

I'll test that on monday.. i have to go to my "chalet" near Mont Megantic this weekend and will comeback sunday night

I posted 4 new video on youtube.. they should be completly uploaded in less than 1hour... all done with the nine continent... still not using my powerfull crystalyte beast... but that will happen SOON !!

Enjoy!

Doc

 

[wasp]

hey doc
83kmh you need to update your signature and show your new top speed
and don't forget to change the X5 to 9C

 

[Doctorbass]

hey doc
83kmh you need to update your signature and show your new top speed
and don't forget to change the X5 to 9C

Oh

Yes.. I will !

 

[etard]

This is the best news in hub motors since the invention of the torque arm! :lol: I wonder if Markcycle is following this, his hubmotor would be ridiculous with this kind of switching.

Does this principle apply to other types of motors, electrathon, etek, rc?

Doc,

Can you give a parts list of everything that is needed, and maybe a short tutorial for the common man trying mimic this system? I like your videos, it's very nice to have a face and persona, where so many just post faceless videos of bikes doing this or that.

I have a feeling this post will get lost in the mix since he will be gone all weekend :?

 

[karma]

good test doc i still think its a good idea to have a relay that works with rpm's. working with higher voltages and amps we run the risk of having the same problems that ac motors have when.
thay switch over to delta before maximum rpm. thay draw two manny amps and burn out. the switch on the bar a good idea to enable or disable the System.

so im starting my work on that idea :wink:

cheers

 

[johnrobholmes]

I need to sit down and draw it out, but there will be a certain way to reterminate the wires so that the Hall sensors are still correct.



I think that hubmotors are terminated Wye because it is easy, and there is room in the motor. The winders have less turns to worry about. In RC motors they terminate Delta in most outrunners, because there isn't much room inside for a Wye junction.

 

[Doctorbass]

EVERY brushless motor that end with 3 phase wires AND non angled stator tooth ! can be mooded in DELTA STAR mode

To mod yours

You need:

-a brushless motor with 3 phase wire(usually they all have 3 phase in ebike and RC)
-you need one 3PDT relay or contactor(or 3 x SPDP that are activated at the exact same time by wiring their coil together)
-a bit of your time to mod your actual motor by opening it and taking the 3 phase wires that are soldered ogether inside the motor(coming from the winding) and to seperate them.
-Installing one wire to every of these 3 seperated tab from the winding to finally acheive 2 wires per phase.

see the image i took here for you:

 

[Doctorbass]

One excellent solution to find a 3PDT or 3x SPDT relay is to buy from ebay some of these car relay:

http://cgi.ebay.com/ebaymotors/OEM-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

10$ each with wiring harness good to up to 40A each.

They have a 12V coil so by connecting them 3x 12v coil in serie you get a 36V coil relay that is perfect to directly connect on most ebike setup battery ! + by connecting them in serie you ensure that each coil receive the exact same current so that help to ensure they will switch ALL AT THE SAME TIME that is very important !

These relay are so small than they could fin inside a normal X5 motor i guess ! but this is not necessary if you have no enough room inside your motor.. puting them close enough to the exterior of the motor is ok.

Their contact rating is 12Vdc but in AC it is like 10x more so there is no problem about that !

so that mode would cost you around 30$ for a speed gain of around 1.5 times!

 

[karma]

yes one relay per phase works well very smooth :wink:

and thats only 10amps each. not my final setup but worked great for the test.
i never throw anything out so ill use this old brushed controller case,turn it into a phase box

 

[fechter]

Good work Doc,

It would be nice to find a relay flat enough to fit inside the motor housing.

It would also be nice to find an impulse relay that only takes power during switching and is off most of the time.