Regenerative Braking System

[Leslie]

Yes with the led lamp hall tester circuit the hall fires like this in the picture.  One on and two off, and two on and one off. 

From GM site.

Magic Pie has 56 Magnets, 63 slots and 56 poles. In other terms, it has 20% more strength and torque than typical motors. With it's large 320mm diameter, there's no hill too steep for it.

Three slots in the gif takes one cycle.

So 63 of the should take 21 3 phase cycles?


Would that be correct.

Its fire order is by the powercroco calcultor.

AaABbBCcCAaABbBCcCAaABbBCcCAaABbBCcCAaABbBCcCAaABbBCcCAaABbBCcC

[gf3]

how I think it work is in the first three phases you have a rotating north pole and in the last three phases you have a rotating south pole so you go passed a pair of magnets in a full six phases so one full revolution in 28 complete cycles but I don't really know.

[gf3]

I don't know if I am slow but I see now how the numbers add up. I couldn't see how 56 magnet lined up with 63 conductors. the answer must be that only half the magnets are being acted upon at any one time. so the important numbers are 14 pair of magnets and 21 conductors a third more conductor. that makes sense.

edit: not sure now but it has to be some thing like that

[gf3]

OK I think I've worked it out
all though there are only 56 magnets there are three types of alignment in line a third off two thirds off.
so 168 individual regions.

every time a switch state changes the wheel turns 1/168 of a turn it takes 28 cycles to turn the wheel one turn

                      6X28=168

[Leslie]

The reason for the odd number in the most efficient machines is IMO to reduce cogging to almost nothing.

I look inside my hub, pull it apart and clunk its sticks to the magnet rim yet it almost has a freewheel restance to roll.  In any symetrical slot pole configuration one magnet is over a slot and to move to the next slot there is cogging.

My HBS is 51 slots and 46 poles again totally odd number.  The phase angle is set to fire over the slot at 120 degrees or 120/360ths along the pole.

Much needs to be learned here.  The radius of both the stator and magnet rim, length of magnet, hall placement and magnet to pole count needs to work.

63 slots can also use 42 poles with a ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC winding config.

63 slots can also use 38 poles with a ABCbcabcBCABCAcabcaCABCAcabcaCABCABabcabABCABabcabABCABCbcabcBC winding config

63 slots can also use 30 poles AbaBAbaBcbCBcbCacACacAbaBAbaBcbCBcbCacACacAbaBAbaBcbCBcbCacACac

63 slots can use 28 poles AbaBcbCacAbaBcbCacAbaBcbCacAbaBcbCacAbaBcbCacAbaBcbCacAbaBcbCac

And by this point this can go all the way down by 2 poles to 2 poles only and the winding configs change .

63 slots by 2 poles. AAAAAAAAAAAbbbbbbbbbbCCCCCCCCCCCaaaaaaaaaaBBBBBBBBBBBcccccccccc  WHAT THE  

Why?

If you cant tell me I would apreciate it.  I am converging a lot of information over the past two years I just need to climatise to the whole thing,,

I found a site called powercroco and it has a calculator and much information written up by a  Dr. Ralph Okon.

Google powercroco and hit the google translate link.  There is much more very awesome resources there than just this cool calculator.

Learn lots and enjoy.

[Leslie]

Three slots and two poles is ABC. 

The amount of slots can be less than poles too

Every config in the powercroco calculator do not have an odd number of slots either.

I almost got te algorithm going in my head how to do the math.  Its teasing me. 

[Leslie]

The slot to poll count and their start and end points must be compatible with the phase angle at any part of the cycle.  And I think the magic number is 360 and its divisons by 120 deg and its relation to pole count.

Im trying to work this out myself and make my own theory up and rediscover the math.  If I cant do this without being told or looking it up then I don't have the right stuff to be the inventor I desire to be.  Even thiough someone has plunged their flag on this mountain I want to able to plunge it off my own steam.

Ignorant maybe.  But I'd rather climb mount everest than take the heli ride to the top.  I hope you see my metaphor and not think I am crazy.  LOL

I find this stuff a decent challenge.

[gf3]

OK so I have 63 slots so 21 slots per phase. but two phases are always conducing at the same time. so there are 42 electro magnets on all the time.

think of it as 42 frogs in your motor grabbing the magnet in front and pulling that's 42 little forces but at the same time they are kicking the magnet behind which is another 42 little forces that's 84 forces in total. funny that 84 is half 168.

so when earlier I thought that only half my magnet were being used at one time in fact its only half the regions that are producing a force at any one time.

[gf3]

so your motor has 46 magnets so that is 138 regions.
it has 51 slots so 17 slots per phase
34 magnets on all the time
68 little force
2x68=136

ah that didn't work out like I expected

[gf3]

just went on to the German site and can see what you mean with the AAaBb ect that just confuses things even more.

I was sure I had worked some thing out with the pole to slot count. I will have to think about it some more. any way its bank holiday Monday here in good old blighty I think Ill pop down the pub on my pie. 

[Leslie]

We will crack the code.  

Each magnet is NSNSNSNSNSNSNSNSNSN yada yada.

This must correspond to the A a B b C c which winding polarity. A is N and a is S.

63 slots can also use 42 poles with a ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC winding config.

The above slots are all wound in one direction regardless of NS magnet placement.  You need to consider phase angle too.  Its just to big to focus on the slot and pole count.  somewhere in the above config the overlap allows for the winding to work wound in a single direction.

Am I making it any easier for you.

[Leslie]

I drew this up for my own reference.

I think I will draw the magnets and add some sensors around it very soon to make it like the motor.

This will make more sense as to how it works.

As you see the 46 poles must require a larger magnet than the slot.  Each extends.

[gf3]

It's quite complicated but I've got a sort of understanding how it works. I understand how if there are 1.5 time as many slots as poles then it comes out ABCABCABC   I think it comes down to the in line a third off two thirds off.

[gf3]

I think the pie is mathematically more pure than your motor with all the clusters of AaA and bBb all being three in length.

If the ratio of poles to slots is 2 to 3 then you get ABCABC
if the ratio of poles to slots is 5 to 6 then you get AaBbCc
the pie is a ratio of 8 to 9 so you get clusters of three
11 to 12 will give you clusters of four
14 to 15 will give you clusters of five. I would have to write a program to work out all the more less pure ratios

[Leslie]

I think the pie is mathematically more pure than your motor with all the clusters of AaA and bBb all being three in length.

If the ratio of poles to slots is 2 to 3 then you get ABCABC
if the ratio of poles to slots is 5 to 6 then you get AaBbCc
the pie is a ratio of 8 to 9 so you get clusters of three
11 to 12 will give you clusters of four
14 to 15 will give you clusters of five. I would have to write a program to work out all the more less pure ratios

Yes I agree to this.  Well sort of.

Away from this.  There is more reasons why the pie may have more slots.



I think its all about the division of 360 degrees or any circle, given that 360 degrees is just another division and a less than desirable system in real world applications, so lets call it 1.  1/63 has a 0.0027 Granularity compared 51/1 = 0.0196 Granularity.  

0.154698605 degrees accuracy compared to 1.088 degrees accuracy is the worst it can get at the closest radius in existence .  Do you know of the vernier scale measurement.

http://en.wikipedia.org/wiki/Vernier_scale

It hands some explaination as to why a long barrel riffle is more accurate than a hand gun in the hands of us mortals. And touches where the reistance of cogging goes to.  Higher divisablilty of radium of any object can achieve a very high engineering specification with a more standard measurement tool.

Higher divisablity of the resistance of each pole with off sets, so to reduce the cogging effect of pole passing each slot applied equally around the entire motor..

This is why I want the larger radius pie over any of the other competitors.  It has become apparent to me that the more increase the the radius of a motor the less accuracy is introduced.  this is why more slots are wise on a larger radius motor IMHO.

The more slots the easier higher accuracy of triggering is achieved.  And so too the less resistance cogging may be apparent with the higher slot count by this divisablity.