Ashwoods Axial flux 15kw, $1k ?

Hillhater

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specifications and price seem good , but its a bit "porky" at 19kg ! :shock:
Looks to be similar size to the "Agni" ..??
could be a good choice for a full Moto conversion though ?
http://www.ashwoods.org/ashwoods_motors.php
http://www.ashwoods.org/doclib/Ashwoods%20Axial%20Flux%20Single%20Rotor%20Motor.pdf
new_motors7.jpg

new_motors4.jpg
 
It's only rated for 3 kW continuous :shock: For that kind of weight you would hope for at least 25 kW peak.

Might be good for a light weight motorcycle like a postie or something, but it's not a particularly useful power range. Cheap though.
 
I dont know the detail, but reports suggest they can run up to 400V and 60kW using a liquid cooling option.
Apparently they are already in production use for Hybrid vans in the UK.
http://www.evworld.com/news.cfm?rssid=30401
The low cost, efficient, and powerful axial flux permanent magnet motor is now in full production at Ashwoods’ UK assembly facility in Exeter, Devon. Over 94% efficient, the range of motors can operate from 24V to 400V and produce 2kW to 60kW of continuous power. An innovative cooling system, developed in-house, allows for excellent heat dissipation.
 
jonescg said:
It's only rated for 3 kW continuous :shock: For that kind of weight you would hope for at least 25 kW peak.

Might be good for a light weight motorcycle like a postie or something, but it's not a particularly useful power range. Cheap though.

Analysing the datasheet closely, the 3Kw continuous rating is for the motor being run in air-cooled only configuration. The way I interpret the photo's of the motor is that they only make the one air/liquid cooled model in this size class which is able to be run in either configuration (liquid ports are bunged-up in the datasheet's photo). It still doesn't explain why they don't list the performance specs for liquid cooling setup though..... :roll: Continuous power would be waaaaaaay higher. WhyTF wouldn't they want to show-off the highest performance setup specs as well? :roll:

EDIT: I've emailed them to clarify this and advise on liquid cooling specs
 
This looks like a newer version of the datasheet, which says 15kg
http://www.ashwoodselectricmotors.com/wp-content/uploads/2013/05/spec-sheet.pdf
From:
http://www.ashwoodselectricmotors.com/

I think the efficiency map looks odd. It looks like it's a cropped version of the real one. Probably on purpose, to keep the real specifications hidden.

But overall, it looks very similar to the Agni, as someone noted. Both in specifications and size. EDIT: but since this is brushless, you should be able to run it above spec without getting issues with the brushes.

Above 70Nm peak @ 600A RMS. That means it should be capable of 70hp at 7000 RPM, if run with enough voltage.
 
Well, if it's made to be liquid cooled, then those specs in the air cooled version doesn't surprise me at all.
 
It seems like this motor has a single rotor.

They also have one with twin rotors, it seems.

Found this old pdf:
http://www.elvis-energy.com/files/file/Axial_Flux_Twin_Rotor_Motor.pdf

And also this one, with some info about their technology, and manufacturing process:
http://www.automotivecouncil.co.uk/wp-content/uploads/2012/07/Ashwoods-Motors-for-Circulation.pdf
 
circuit said:
Seriously, it's one of main parameters these days, as you could end up with a fantastic motor, that can not be driven by any kind of controller...
I agree 100%. I wish everyone included it in their specification.
 
Miles said:
circuit said:
Seriously, it's one of main parameters these days, as you could end up with a fantastic motor, that can not be driven by any kind of controller...
I agree 100%. I wish everyone included it in their specification.
None do. Actually I did see one datasheet with inductance specified.. Can't recall the brand.
But if everyone did, they would loose big part of sales and interest. Of cause many buyers still have no clue what they are going into.
It is interesting how they are able to do specification tests, because you need actual controller for that. I guess they are either using enormous inductors for tests, or simply write down numbers from theoretical calculations...

Don't know about this one though.
 
I have seen a few motor datasheets with all electrical properties specified. Not uncommon on motors made for industrial use. I also recall that it was specified for that <1kg ironless axial flux motor with high specific power that was developed a few years ago.

I still don't think that you should rule out a motor because of low inductance. First of all, if you run it at low voltage, it will work just fine with a standard controller. But you won't get full performance out of it, of course. Secondly, as I argued in another thread a long time ago, you need lower inductance to make more power. Simply a mathematical fact. I'm not the only one of that opinion; brushed DC motors were constantly developed towards lower inductance. One of the best brushed motor design is the Agni, and it has a low inductance. They need less advance at high speed/torque.

As you say, the problem is that some (many) controllers doesn't work with all sorts of motors. But the technology to run these motors exists.

You seem to be running a campaign against low inductance motors. In my opinion, it is very bad engineering to rule out new technology simply because one of their properties makes them hard to use. It's like sticking to cast iron pistons because the aluminum ones melt.
 
circuit said:
Miles said:
circuit said:
Seriously, it's one of main parameters these days, as you could end up with a fantastic motor, that can not be driven by any kind of controller...
I agree 100%. I wish everyone included it in their specification.
None do. Actually I did see one datasheet with inductance specified.. Can't recall the brand.
.....


GoldenMotor do for the HPM5000B & HPM10000B in all 3 winding options:

From their product page:

HPM5000B

Phase Resistance (Milliohm): 6.2/48V; 12.0/72V; 36.0/120V
Phase Induction(100KHZ): 68uH/48V; 154uH/72V; 504uH/120v

HPM10000B

Phase Resistance (Milliohm): 3.1/48V; 6.0/72V; 18.0/120V
Phase Induction(100KHZ): 34uH/48V; 77uH/72V; 252uH/120v

HPM5000B....the 0.59Nm/Kg US$600 delivered boat anchor competitor with the Ashwoods offering
HPM5000B_internal_cross_section_drawing.jpg
 
bearing said:
I still don't think that you should rule out a motor because of low inductance.
Of course you should not rule it out from "motors", however this gives you a better understanding of your options. If that motor is very light and cheap - great, but if you need 5x more expensive and 3x heavy controller for it - maybe not so great. May be desirable for some specific applications, but certainly not for most of them.

bearing said:
Secondly, as I argued in another thread a long time ago, you need lower inductance to make more power. Simply a mathematical fact. I'm not the only one of that opinion; brushed DC motors were constantly developed towards lower inductance. One of the best brushed motor design is the Agni, and it has a low inductance. They need less advance at high speed/torque.
How low is Agni? Dealt with it many times, but did not measure inductance..
Low inductance is important in brushed high speed motors, because you can't adjust the angle of the brushes, it is fixed. So yes, at high RPM you start getting problems, such as power loss of arcing. Same goes for PMAC (BLDC) motors with cheap controllers (trapezoidal communication), where phases are being generated blindly, relying only on hall signals. With higher end controllers, which are based on SVPWM and FOC algorithms, that is not a problem.

bearing said:
As you say, the problem is that some (many) controllers doesn't work with all sorts of motors. But the technology to run these motors exists.
Yes it does. But at what cost? I've seen some techniques in theory, read some patents on driving low inductance motors... But have not seen a viable real-world solution. By real-world I mean solution that not only is working well, but also is technically and economically viable.
BTW could you list some controllers that are suitable to drive motors at 100V with inductance less than 5μH? I'm just curious and hope that these are actually possible to buy. and 5μH is quite generous, as those coreless motors, I guess, can't even reach 1μH.

bearing said:
You seem to be running a campaign against low inductance motors. In my opinion, it is very bad engineering to rule out new technology simply because one of their properties makes them hard to use. It's like sticking to cast iron pistons because the aluminum ones melt.
I'm "running campaign against low induction" because I've dealt with them numerous times and had a very hard time. I'd sit silent if I did not see endless discussions on the forums about various motors and problems running them. Many of members have no idea why are they having those problems in the first place. So I feel like I need to spread the word: beware, these motors are clearly not for you, if you don't know what inductance does and how to cope with it.
Few years passed and people are still discussing about running large RC motors, such as CA80100, CA120, etc... I've said it many time: these have low inductance and are really hard on controller. But many have no idea what inductance is and simply ignore it, focusing on things they understand.
 
circuit said:
BTW could you list some controllers that are suitable to drive motors at 100V with inductance less than 5μH?

I'm not aware of any of those controllers. It would need to switch faster than the typical controller. As I see it, the switching frequency should be increased proportional to the battery voltage, and inversely proportional to the inductance and max current of the motor. Then the ripple as a percentage of max current will stay the same.

circuit said:
5μH is quite generous, as those coreless motors, I guess, can't even reach 1μH.

This little coreless motor that I was referring to has 3.9uH @ 69kV, and runs 120V 50A.
http://www.launchpnt.com/Portals/53140/docs/dual-halbach-motor-data-sheet_r1.pdf

It would need 200kHz switching frequency, IMO. And that should be possible with modern SMD power MOSFETs.
 
circuit said:
Miles said:
circuit said:
Seriously, it's one of main parameters these days, as you could end up with a fantastic motor, that can not be driven by any kind of controller...
I agree 100%. I wish everyone included it in their specification.
None do. Actually I did see one datasheet with inductance specified.. Can't recall the brand.
But if everyone did, they would loose big part of sales and interest. Of cause many buyers still have no clue what they are going into.
It is interesting how they are able to do specification tests, because you need actual controller for that. I guess they are either using enormous inductors for tests, or simply write down numbers from theoretical calculations...

Don't know about this one though.
Chances are if they spent the money on bringing the motor to market then they spent the money on a good controller to run it.
Remember there is controllers other then cheep ebike controllers out there ;)
 
Arlo1 said:
Chances are if they spent the money on bringing the motor to market then they spent the money on a good controller to run it.
Remember there is controllers other then cheep ebike controllers out there ;)
Yes I know. Actually I have experience with some of those. However, I did not find any that can run low inductance, at any cost. Understanding of complexity low inductance brings and techniques to deal with it, I imagine these controllers, if any, to be extremely heavy, inefficient and expensive. It just does not justify lower motor weight and price.
 
circuit said:
Arlo1 said:
Chances are if they spent the money on bringing the motor to market then they spent the money on a good controller to run it.
Remember there is controllers other then cheep ebike controllers out there ;)
Yes I know. Actually I have experience with some of those. However, I did not find any that can run low inductance, at any cost. Understanding of complexity low inductance brings and techniques to deal with it, I imagine these controllers, if any, to be extremely heavy, inefficient and expensive. It just does not justify lower motor weight and price.
I don't know... How low of inductance is low? 8uh? I am having good luck. I am not an engineer of any type just building it as a hobby. If I can make colossus run with some backyard controller I build then anyone who has the right training can do it better. Its all about the control algorithm.
 
circuit said:
bearing said:
I still don't think that you should rule out a motor because of low inductance.
Of course you should not rule it out from "motors", however this gives you a better understanding of your options. If that motor is very light and cheap - great, but if you need 5x more expensive and 3x heavy controller for it - maybe not so great. May be desirable for some specific applications, but certainly not for most of them.

bearing said:
Secondly, as I argued in another thread a long time ago, you need lower inductance to make more power. Simply a mathematical fact. I'm not the only one of that opinion; brushed DC motors were constantly developed towards lower inductance. One of the best brushed motor design is the Agni, and it has a low inductance. They need less advance at high speed/torque.
How low is Agni? Dealt with it many times, but did not measure inductance..
Low inductance is important in brushed high speed motors, because you can't adjust the angle of the brushes, it is fixed. So yes, at high RPM you start getting problems, such as power loss of arcing. Same goes for PMAC (BLDC) motors with cheap controllers (trapezoidal communication), where phases are being generated blindly, relying only on hall signals. With higher end controllers, which are based on SVPWM and FOC algorithms, that is not a problem.

bearing said:
As you say, the problem is that some (many) controllers doesn't work with all sorts of motors. But the technology to run these motors exists.
Yes it does. But at what cost? I've seen some techniques in theory, read some patents on driving low inductance motors... But have not seen a viable real-world solution. By real-world I mean solution that not only is working well, but also is technically and economically viable.
BTW could you list some controllers that are suitable to drive motors at 100V with inductance less than 5μH? I'm just curious and hope that these are actually possible to buy. and 5μH is quite generous, as those coreless motors, I guess, can't even reach 1μH.

bearing said:
You seem to be running a campaign against low inductance motors. In my opinion, it is very bad engineering to rule out new technology simply because one of their properties makes them hard to use. It's like sticking to cast iron pistons because the aluminum ones melt.
I'm "running campaign against low induction" because I've dealt with them numerous times and had a very hard time. I'd sit silent if I did not see endless discussions on the forums about various motors and problems running them. Many of members have no idea why are they having those problems in the first place. So I feel like I need to spread the word: beware, these motors are clearly not for you, if you don't know what inductance does and how to cope with it.
Few years passed and people are still discussing about running large RC motors, such as CA80100, CA120, etc... I've said it many time: these have low inductance and are really hard on controller. But many have no idea what inductance is and simply ignore it, focusing on things they understand.

fair enough circuit, you were beaten up by a low inductance motor as a child, but now you are going beyond limiting yourself and your own options, and trying to limit everyone else s as well. you are now having to deny this: http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=16728&hilit=12kw+rc+motor&start=1725#p724695 (a $1000 Kelly khb easily overdoing it by putting over 500amps into an 8.5uh collosus and merrily producing 14kw output at the tyre)

also completely not possible is this: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=50518&p=751024&hilit=ca120#p751024 (a ca120 bike that i have it on good authority runs a Kelly keb $489 1.4kg controller)

ive this alone after you told me it was just a matter of time before the kelly would blow by running it on the colossus etc, and i learned about the 35a no load phase current ripple issues from you, but here we are im afraid another 6 months on of daily riding with STILL no blow ups, and just to ice the cake i yesterday ran a saturation test on some ca120's, a joby, and then a collosus, putting current into a completely locked rotor, and measuring NM. the ca120 and joby were saturating around 200-250a running 75V battery but the big collosus needed 400A to see it, and this was all done using the same tortured little 1.4kg Kelly :!: -to be honest it was stupid to risk it, running a motor over double the size, AND double the phase current was just asking for trouble.. but it lives on.

i really dont know what we can do for you circuit, i know you believe nothing of this, but i can show you cro shots of the 33khz pwm phase currents into a locked rotor ca120 (yes indeed with low inductance caused large current spikes) or whatever else you want to prove that what i have said is solid, but if you dont take me up on this and just refuse to believe just on principal alone, then its not much use holding everyone who reads this back with your own perceived limitations.
 
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