12 kw rc motor

[zEEz]

Note I have not hooked up the water cooling on this yet so until I get my full battery pack and the cooling I will not be pushing it much harder.

7kW stable no plasma without water cooling and chopped battery?
So far so good ..... I would say it is working REALLY fine ...

Wish I could experiment with something like this once in the near future!

have lots of fun!

[Arlo1]

I havent looked to much at the RIMAC concept one but.... HOLY SHIT I wana sell every thing I own that burns gas and make an electric car like that! IS it possible it uses 4 giant versions of colossus?

[markobetti]

Splinter - great stuff !
I am not working on RIMAC project..Hal is ... Two big giant motors are not in anyway affiliated with colossus , those motors are by the way inrunners as i can see. Colossus motors are still in test mode (we didnt run it with new controller), and hal is busy so he didnt have time to put it on Egenric. Arlo and Splinter have the motors since they are the first two guys who wanted them badly enough and had experience or friends that can help if something goes wrong. We are working on them , i have made something new ; so i am waiting for factory to send it a . After 3 months we will start taking orders i think. Just give us time to get all bugs controller-motor figured out .

[markobetti]

Splint , do you have cycle analyst ? Some readings from it ?...would be good

[SplinterOz]

Splint , do you have cycle analyst ? Some readings from it ?...would be good

I am not running the Cycle Analyst I have as it is a direct plugin model and that does not work with the Kelly.
However I am going to rig up a small camera, volt meter, amp meter and GPS speedo so you can all see how it is going. Give me a day or so.

[zEEz]

We are working on them , i have made something new ; so i am waiting for factory to send it a . After 3 months we will start taking orders i think. Just give us time to get all bugs controller-motor figured out .

Ah, good, thanx for the info! Just let us know when Christmas Orders will start !!!

have fun!

[markobetti]

Splint , do you have cycle analyst ? Some readings from it ?...would be good

I am not running the Cycle Analyst I have as it is a direct plugin model and that does not work with the Kelly.
However I am going to rig up a small camera, volt meter, amp meter and GPS speedo so you can all see how it is going. Give me a day or so.

Shitzz..if you were in Croatia , me and my pal Grga would put so many instruments on your motorbike from cycle analyst to couple of dozen volt meters that you would look like New Year crithsmas in New York.. Doesent anybody have the version you need near you - just for you to abuse it for a while ..? Basically Cycle analyst records also peak power , my other instruments dont do that... Well i know one that is being made here in Croatia , it will record anything....but still in early stages...

[Arlo1]

Splint , do you have cycle analyst ? Some readings from it ?...would be good

I am not running the Cycle Analyst I have as it is a direct plugin model and that does not work with the Kelly.
However I am going to rig up a small camera, volt meter, amp meter and GPS speedo so you can all see how it is going. Give me a day or so.

If you follow the wiring you can open up the Kelly and install the CA to work with it. Just have to cut the end of the CA wire plug off and solder the wires where they need to go on the circuit board.

[SplinterOz]

If you follow the wiring you can open up the Kelly and install the CA to work with it. Just have to cut the end of the CA wire plug off and solder the wires where they need to go on the circuit board.

Arlo1, I am quite happy to leave my working and in warranty Kelly intact. I might be able to get hold of a cycle analyst and shunt later this week. That would allow some real data.
However I can get nearly all the same info with a amp meter (already on the bike), speedo (have to put on the magnet) and volt meter. That will give me the instantaneous usage at any time for any given speed. I just don't know Wh per km not a big deal at the moment.

[Arlo1]

If you follow the wiring you can open up the Kelly and install the CA to work with it. Just have to cut the end of the CA wire plug off and solder the wires where they need to go on the circuit board.

Arlo1, I am quite happy to leave my working and in warranty Kelly intact. I might be able to get hold of a cycle analyst and shunt later this week. That would allow some real data.
However I can get nearly all the same info with a amp meter (already on the bike), speedo (have to put on the magnet) and volt meter. That will give me the instantaneous usage at any time for any given speed. I just don't know Wh per km not a big deal at the moment.

Yeh if you have the data you need its not worth the hasle. Have you got something to watch phase amps?

[SplinterOz]

If you follow the wiring you can open up the Kelly and install the CA to work with it. Just have to cut the end of the CA wire plug off and solder the wires where they need to go on the circuit board.

Arlo1, I am quite happy to leave my working and in warranty Kelly intact. I might be able to get hold of a cycle analyst and shunt later this week. That would allow some real data.
However I can get nearly all the same info with a amp meter (already on the bike), speedo (have to put on the magnet) and volt meter. That will give me the instantaneous usage at any time for any given speed. I just don't know Wh per km not a big deal at the moment.

Yeh if you have the data you need its not worth the hasle. Have you got something to watch phase amps?

I think I can strap a clamp meter onto the bike for that measurement... might be hard to get it into the same camera shot though.

[SplinterOz]

Here is the bike running.

Note the 1030 is the battery Amps multiplied by 10, using a neat gizmo from Zeva to drive the tacho.

So for the hard of seeing...
78km/h
67 Volts (boy these headways sag)
103 amps

This makes for 6.9Kw for 78Km/h not too bad.

[zEEz]

Hey SplinterOz!
Your motorbike is already useable for short range commuting ... that is Great!
are you planning to add more headways???

I wonder how fast you could go with full motor current and Liquid Cooling ...
130kmph should be there ...

Do you plan to make it street legal? How it is with regulations in Australia?

have fun!

[SplinterOz]

Hey SplinterOz!
Your motorbike is already useable for short range commuting ... that is Great!
are you planning to add more headways???

I wonder how fast you could go with full motor current and Liquid Cooling ...
130kmph should be there ...

Do you plan to make it street legal? How it is with regulations in Australia?

have fun!

Here is the link to my build thread... http://endless-sphere.com/forums/viewtopic.php?f=10&t=25697.
But to answer your questions...
24S5P of Headway's 10ah
Full motor current and water cooling is in the works.
The ADR (Australian Design Rules) have a section on modified motorcycle and another on EV conversions. I just have to comply and get an Engineer's Certificate.

Already having fun.

[zEEz]

The ADR (Australian Design Rules) have a section on modified motorcycle and another on EV conversions. I just have to comply and get an Engineer's Certificate.

Already having fun.

Great news! It is a pity that in Europe the modifications to EV are more difficult to legalize

I understand your fun and the fact that with 50Ah-75v battery it can last enough long
between each charge

have fun!

[Arlo1]

Ok So Today I worked all the numbers and here is my verdict. From what I have researched and somewhat tested you need ~100uH a phase for inductance for a controller to live. Stock colossus has 8uh! What we need is to wind it to 35kv and terminate it in WYE! I worked all the numbers and it will work out to be 10 turns a tooth and 106uH inductance split into 2 separate stators just look at it as a bottom 1/2 and a top 1/2 for 9 stator teeth a section each section will have 3 for phase A 3 for B and 3 for C Then the bottom 1/2 will need to be completely separate from the top but can still be fired off the same set of halls. So for the controller we will need 6 H bridges 2 groups of 3 then the mosfets will be working with the same kv but 2x the inductance causing less heat and better control.

I have one of the 24 fet boards left I will try to cut the pad in 1/2 for each phase and build one up for this weekend to show you all!
Cheers.
Arlin.

[zEEz]

I have one of the 24 fet boards left I will try to cut the pad in 1/2 for each phase and build one up for this weekend to show you all!
Cheers.
Arlin.

Arlo, I think 12 fet for each set of 3 winds is too little if you plan to apply any kind of load to the rotor ...
IT WILL BLOW AND IT IS A PITY ...
I use a 36 fet controller with the ME0907 motor that is 120uH ... would say 24 mosfet is the minimum ...
Don't want to bring you bad luck, just telling you to wait to have the proper tools ...
... I know the desire to see something working is tempting ... but I would avoid to look for troubles ...

have fun!

[Lebowski]

Ok So Today I worked all the numbers and here is my verdict. From what I have researched and somewhat tested you need ~100uH a phase for inductance for a controller to live. Stock colossus has 8uh!

I don't see what the problem is with 8uH and why it would need te be 100uH. As far as I know the current in an inductor follows:

V = L * delta_I/delta_t

with 100V and 8uH the delta_I/delta_t is 12.5 M Amps/sec (assuming the motor is not rotating yet and back-emf = 0V)

If you're running 20 kHz PWM with let's say 10% dutycycle (at motorstart) this means:
20 kHz => this is 50 usec, at 10% -> the current is allowed to increase for 5 usec -> the current increases by 62 Amps !
And this for only 10% dutycycle ! No wonder stuff goes up in smoke

An extra 100uH decreases the current increase to around 5 Amps. This is survivable but it's not an elegant fix.

I would say the real fix is not an external inductance but an increase of the PWM to a few 100 kHz to 1 MHz.
The main issue then is that you need to beef up the mosfet drivers to be able to handle the switching rate
but this should not be a big issue. In class D audio amplifiers (which drive the same mosfet output stage)
a few 100 kHz is normal...

[Arlo1]

Ok So Today I worked all the numbers and here is my verdict. From what I have researched and somewhat tested you need ~100uH a phase for inductance for a controller to live. Stock colossus has 8uh!

I don't see what the problem is with 8uH and why it would need te be 100uH. As far as I know the current in an inductor follows:

V = L * delta_I/delta_t

with 100V and 8uH the delta_I/delta_t is 12.5 M Amps/sec (assuming the motor is not rotating yet and back-emf = 0V)

If you're running 20 kHz PWM with let's say 10% dutycycle (at motorstart) this means:
20 kHz => this is 50 usec, at 10% -> the current is allowed to increase for 5 usec -> the current increases by 62 Amps !
And this for only 10% dutycycle ! No wonder stuff goes up in smoke

An extra 100uH decreases the current increase to around 5 Amps. This is survivable but it's not an elegant fix.

I would say the real fix is not an external inductance but an increase of the PWM to a few 100 kHz to 1 MHz.
The main issue then is that you need to beef up the mosfet drivers to be able to handle the switching rate
but this should not be a big issue. In class D audio amplifiers (which drive the same mosfet output stage)
a few 100 kHz is normal...

Im just starting with 100uH because of other prople in the world have had to aim for that humber or more to keep their controllers happy.

Having a uber low inductance like 8uH will cause significant switching losses. When mosefets or igbts come out that have shorter on time and off times the switching losses will be reduced then it will be easier to run a motor with less inductance. My 24 4110 mosfet controller blows a fet stage in 20-25uS with a combinded on and off time of 155nS on the irfb4110 the fets are getting a lot of heat just from switching. So if they even turned on and off for a max on time of say 20 uS they will still get a crazy amount of switching heat and be destroyed.

I am going at this will a few different angles of attack. But by summer next year I will have pushed colossus past its limits.
I am still waiting for splinter to run his at hi power and see how the kelly holds up!

[zEEz]

Having a uber low inductance like 8uH will cause significant switching losses. When mosefets or igbts come out that have shorter on time and off times the switching losses will be reduced then it will be easier to run a motor with less inductance. My 24 4110 mosfet controller blows a fet stage in 20-25uS with a combinded on and off time of 155nS on the irfb4110 the fets are getting a lot of heat just from switching. So if they even turned on and off for a max on time of say 20 uS they will still get a crazy amount of switching heat and be destroyed.

Lebowsky, in this Arlo is right ... a D-class audio amplifier is working reasonably at hundreds of kHz pwm
frequency just because the load has a resistance bigger than 2 ohm and a fairly high inductance ...
When they get to kW amplifications, it is always multichannel and multiways ... so the power is limited ...

Here we want 20kW on one output, so it is a problem for the output stage ...

have fun!

[Arlo1]

I have one of the 24 fet boards left I will try to cut the pad in 1/2 for each phase and build one up for this weekend to show you all!
Cheers.
Arlin.

Arlo, I think 12 fet for each set of 3 winds is too little if you plan to apply any kind of load to the rotor ...
IT WILL BLOW AND IT IS A PITY ...
I use a 36 fet controller with the ME0907 motor that is 120uH ... would say 24 mosfet is the minimum ...
Don't want to bring you bad luck, just telling you to wait to have the proper tools ...
... I know the desire to see something working is tempting ... but I would avoid to look for troubles ...

have fun!

Thanks im building a better controller. But as a test i want to do this i know 12 fets a motor is not a lot but it will be about the same as the small colossus in terms of how hard it is on fets!

[Lebowski]

Arlo can you explain what you mean by 'combined on/off time of 155 nsec' ? And by '20 usec on time' ?
20usec seems awfully long, current will shoot up by feww hunderd Amps in that time...

[Arlo1]

Arlo can you explain what you mean by 'combined on/off time of 155 nsec' ? And by '20 usec on time' ?
20usec seems awfully long, current will shoot up by few hundred Amps in that time...

My data sheets for the irfp4110gpbf show an rise time of 67nS and a fall time of 88nS Then added together that's 155nS of switching time. Every time you send an on pulse through one of those fets its going to spend 67nS turing on and 88nS turning off for a total of 155nS in transition per switched on event which during the switching time it is going to produce far more heat inside the mosfet then the rdson value.
The 20uS was a calc from a spread sheet bigmoose gave me to play with it is posted on my inductance thread. The thing is if the fet can only be on for ~20uS in perfect world conditions before its destroyed then its going to have to switch on and off more frequently which causes more heat (and stress) inside the fet it self!

Remember I am looking to build a 50+KW controller!

Here is a screen shot motor A is colossus in stock form note how at the 25uS mark the amps are to hi for a 24 fet controller with 4110 mosfets!

[bearing]

Stock colossus has 8uh! What we need is to wind it to 35kv and terminate it in WYE! I worked all the numbers and it will work out to be 10 turns a tooth and 106uH inductance

Rewinding the motor to get higher inductance will not help, unless you plan to keep the same battery voltage as before the rewind (and get less power in the process).

If you double the amount of winding turns, the inductance will get 4 times higher, and the kV will be halfed. 4 times more inductance will lower rise rate in windings by a factor of 4, and I guess that is what you seek. However, when you double battery voltage to get the same RPM as before the rewind, then you double the rise rate, which will put you at half of what the rise rate initially was. Further, with a halfed kV, the peak current will be halved. So, if the peak current is halfed, and the rise rate is halfed, then the rise time will be the same as it originally was.

If you want to lower the rise time (EDIT, I mean increase rise time / lower rise rate), you could just lower battery voltage, it will have the exact same effect as rewinding the motor without changing battery.

Adding external inductance will not help you get to 50kW either IMO, because that added inductance will prevent currents to rise fast enough to get much torque at high RPM.

I once read about a controller for an ironless motor. It had little different approach compared to the common BLDC controllers. It used the 3-phase bridge only to commutate the machine. Then there was also a PWM stage similar to a brushed DC controller. And in between them there was an inductor. So, it was a high power Buck-converter followed by a 3-phase bridge.

I think the normal hardware approach will do though. I think it's a matter of software. My thought is that the software needs to drive the motor with a waveform which corresponds to the EMF of the motor. If the motor is driven with a constant PWM, then I think the current will spike near the end of every commutation step. When the EMF passes the peak and starts to fall, then the difference between EMF and battery voltage will rise, and the current will then rise too. This is just a theory, and I have no experience in making brushless controllers, but I do have some experience with switched inductors.

[Lebowski]

Arlo can you explain what you mean by 'combined on/off time of 155 nsec' ? And by '20 usec on time' ?
20usec seems awfully long, current will shoot up by few hundred Amps in that time...

My data sheets for the irfp4110gpbf show an rise time of 67nS and a fall time of 88nS

Do you realise that to switch on 4 parallel 4110's (like in a 24 fet controller) in 80 nsec you need a 9 (!) Amps gate drive circuit ? And negligible gate series resistance ?