ELECTRIC TRANSMISSION DELTA /WYE and SERIE/PAPALLEL stator

[liveforphysics]

The resistance losses (and therefore heating) are a function of current squared, so a 5302 is going to result in more heating for a given amount of torque...

No no no!
You shorten the wire by the same proportion that its thickened up. Shorter wire change in resistance of x, times thicker wire change in resistance of x, means x*x, makeing resistance drop at the square of turns, which balances perfectly with heat increasing at the square of current, to leave you with copper fill being the only thing that matters in determining the continous torque rate, and they all get identical heating for that torque value if the copper fill matches, etc etc etc...

[John in CR]

Wouldn't the exception to this heating issue during a given takeoff be that the efficiency of the higher turn count motor will increase faster and produce less heat? Also, since our controllers limit the current below the maximum the low turn count motor can take, won't the higher turn count motor have more real world torque as opposed to the theoretical equivalency? I believe the real benefits will show on steep climbs and during lower speed trail riding, where the higher turn count motor will have a distinct advantage by operating in its efficiency band while the low turn count motor is still trying to kill its controller during current limiting.

John

[Doctorbass]

Ok no.. again this debate...

Guys.. once i finished that PCB thing i'll try it and will post results and will see...

everythig i'm doing now for thst DH ebike need custom parts.. = welsing, laser cuting, cnc cuting, etc.. it take so much time to acheive!!! and guess what... it's vacancy period here so all industrial CNC and metal worker are 2 next weeks off!!!

I mist use imagination to finish that DH bike project before next monday!!! ( when i'll go to meet BlackArrow at 1000km fron here and by the time, see my familly)... The next days are crucial!!!

tomorrow night i should get the PCB, new torque arm/steel dropout, 12 lipo battery box and C-A... Alot of work to do . but that project will be the best to test the performances of that serie parallel method.. at high power!!

Doc

[John in CR]

Ok no.. again this debate...

Guys.. once i finished that PCB thing i'll try it and will post results and will see...

everythig i'm doing now for thst DH ebike need custom parts.. = welsing, laser cuting, cnc cuting, etc.. it take so much time to acheive!!! and guess what... it's vacancy period here so all industrial CNC and metal worker are 2 next weeks off!!!

I mist use imagination to finish that DH bike project before next monday!!! ( when i'll go to meet BlackArrow at 1000km fron here and by the time, see my familly)... The next days are crucial!!!

tomorrow night i should get the PCB, new torque arm/steel dropout, 12 lipo battery box and C-A... Alot of work to do . but that project will be the best to test the performances of that serie parallel method.. at high power!!

Doc

I hope you're riding the bike the 1kkm to meet up with BA. That would be a great shakedown cruise.

John

[Doctorbass]

Ok no.. again this debate...

Guys.. once i finished that PCB thing i'll try it and will post results and will see...

everythig i'm doing now for thst DH ebike need custom parts.. = welsing, laser cuting, cnc cuting, etc.. it take so much time to acheive!!! and guess what... it's vacancy period here so all industrial CNC and metal worker are 2 next weeks off!!!

I mist use imagination to finish that DH bike project before next monday!!! ( when i'll go to meet BlackArrow at 1000km fron here and by the time, see my familly)... The next days are crucial!!!

tomorrow night i should get the PCB, new torque arm/steel dropout, 12 lipo battery box and C-A... Alot of work to do . but that project will be the best to test the performances of that serie parallel method.. at high power!!

Doc

I hope you're riding the bike the 1kkm to meet up with BA. That would be a great shakedown cruise.

John

Hey.. nice idea.. but with 1.3kWh of lipo i wold need to charge every 50km.. that's 20 stop... 20 stop x 45 minutes charge is 15 hours of charge plus the 20hour of continous run...... 35hour of ebike..

I should add some confortable spring on that DH seat and bring a sleeping bag with me..!

i'll pass this time.. Justin already prooven that long 7000km ride can be acheived.. i'll leave him the credit for incredible long ride!

Doc

[Miles]

Ok no.. again this debate...

It's not really a debate - more like countering the propagation of a common misunderstanding.

[BlackArrow]

I hope you're riding the bike the 1kkm to meet up with BA. That would be a great shakedown cruise.

John

Hi John,

Doc take his car to going here, but we have allot of quad trails here for his new DH ebike and he can test this series/parallel set up in this hostile environment . We can try to make some movie during those rides, and I'm really impatient to see and to ride with Doc, it will be fun no doubt about it

Good day!
Black Arrow

[fechter]

Ok no.. again this debate...

Sorry

Yes, for the motor I see your point about fill, but losses in the phase wires and conduction losses in the FETs will still increase.

I'm reminded of the Ecycle 'Solid Slot' configuration where it's like just a big bar of copper in each slot. If properly driven, seemed to remain pretty efficient.

The key to that system was using a dedicated inductor for the PWM instead of using the motor windings. With very low turns, the inductance of the motor gets pretty low, which you could counteract by using a higher PWM frequency. Motor windings tend to be pretty lossy at higher frequencies (mostly core losses), so they added a high quality inductor/freewheel diode ahead of the motor. Supposedly the lossed avoided in the motor windings more than made up for the losses in the separate inductor.

Long story short, with 2 turns, you might see some improvement if you added some kind of inductance in series with each phase wire.

[John in CR]

Ok no.. again this debate...

Sorry

Yes, for the motor I see your point about fill, but losses in the phase wires and conduction losses in the FETs will still increase.

I'm reminded of the Ecycle 'Solid Slot' configuration where it's like just a big bar of copper in each slot. If properly driven, seemed to remain pretty efficient.

The key to that system was using a dedicated inductor for the PWM instead of using the motor windings. With very low turns, the inductance of the motor gets pretty low, which you could counteract by using a higher PWM frequency. Motor windings tend to be pretty lossy at higher frequencies (mostly core losses), so they added a high quality inductor/freewheel diode ahead of the motor. Supposedly the lossed avoided in the motor windings more than made up for the losses in the separate inductor.

Long story short, with 2 turns, you might see some improvement if you added some kind of inductance in series with each phase wire.

Like what?....Do some smallish loops of our phase wires? If so, how many might do the trick?

[Doctorbass]

The motor serie parallel mod is finished!!!

Now i'm working on the controller and battery.

i'll post results soon!!

DOc

[rkosiorek]

Good to hear Doc! can`t wait to hear your experiences.

i think that you will only be using the high turn count mode only briefly during hard launches. most of the time you will be in the low turn mode.

rick

[steveo]

I hope doc attempt is better then mine lol...





-steveo

[Doctorbass]

It's ALIVE !!!

Motor mod done and it work!!!

I just need to assemble the 12 lipo + BMS in the battery case for 88.8V 15Ah.

No load speed at 100V(psu);

84km/h serie mode

99km/h+ ( CA reading max ) but i expect to be around 170km/h

here is some preview for those who can't wait for the 100+ pics i took and will post soon:

Dont worrie, the little 9 conductor flat is soldered without any short and now is poted in epoxy!!

[rkosiorek]

wow that is a heck of a lot neater than what i ended up with doing point to point wiring. i think that you have proven that this is the way to go if you are going to do it.

how heavy is the copper on the board. was the board etched? or did you just CNC the traces and cutouts for the relay leads.

I WANNA SEE IT RUN> < I WANNA SEE IT RIGHT NOW!!!!>

rick

ps. good looking bike by the way. and i hope you didn't notice, but i have some minor issues with impulse control. leastways thats what my lawyer called it.

[steveo]

It's ALIVE !!!

Motor mod done and it work!!!

I just need to assemble the 12 lipo + BMS in the battery case for 88.8V 15Ah.

No load speed at 100V(psu);

84km/h serie mode

99km/h+ ( CA reading max ) but i expect to be around 170km/h

here is some preview for those who can't wait for the 100+ pics i took and will post soon:

Dont worrie, the little 9 conductor flat is soldered without any short and now is poted in epoxy!!

i gaurente 70mph+ @ 120v!

one word.,,,

AWSOMENESSS!!!!

-steveo