Turnigy Rotomax good pair with PowerVelocity controller?

Electric Motors and Controllers
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Clouse
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Turnigy Rotomax good pair with PowerVelocity controller?

Post by Clouse » Jan 22, 2018 3:29 pm

Hello, I'm new around here. I'm working on a project where I'm looking for a ~10kW motor that is affordable and capable of regen. I've found the Turnigy Rotomax 150 which claims 9.8kW, and a PowerVelocity 15kW bike controller with regen. Will these pair well together? (I may need to add a hall effect sensor to the motor) From my reading they seem to, but before I spend $900 I figured I should check.

I hate being the new guy asking possibly obvious questions, but I did search this forum before I made the post...

Turnigy Rotomax 150 motor
https://hobbyking.com/en_us/turnigy-rot ... motor.html
Spec.
Battery: 14 Cell / 51.8V
RPM: 150kv
Max current: 190A
Watts: 9800w
No load current: 51.8V/5.2A
Internal resistance: 0.011 ohm
Weight: 2530g
Diameter of shaft: 10mm
Winding: 8T
Stator Pole: 24
Motor Pole: 20
Stator Diameter: 101
Lamination Tickness: 0.2mm
Suggested ESC: 250A 14S Compatible

PowerVelocity 15kW controller
http://powervelocity.com/index.php?id_p ... r=product
Spec.
Sinewave power modulation makes motor run very quietly and vibration free
A wide range of features programmable wirelessly from an Android or iOS/iPhone device
Voltage operating range 24-100v, 36-120v or 70-150v
Battery currents up to 150A
Phase currents up to 300A
24 Genuine low resistance (RDS) MOSFETs
Finely adjustable regenerative brake force
Input for 3-position speed or power level switch
Cruise control input
Configurable hard or soft start options
Larger and stronger box for better heat dissipation and performance
Adjustable magnetic flux weakening for higher speeds and efficiency
Tested top unloaded speed with flux weakening enabled: 130mph at 100v
Size 250 x 120 x 70 mm
Weight - 2.3kg
Bluetooth programming via Android/iOS is now included standard

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amberwolf
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Re: Turnigy Rotomax good pair with PowerVelocity controller?

Post by amberwolf » Jan 22, 2018 9:58 pm

You may want to check with the controller manufacturer to see if it can handle the eRPM of teh motor at the speed you want to run it at.

Otherwise the controller may lose sync with the motor at some point, and high currents or stuttering or other problematic behaviors may occur.


If you state the full project details / purpose / needs here in this thread, someone can probably help you find something that will do what you want.

If you like, there is a thread "how to get the proper advice..." https://endless-sphere.com/forums/viewt ... =3&t=66302 that has a list of questions in the first post. I recommend copying those, and pasting them into this thread with your answers, to help people help you. :)

Clouse
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Re: Turnigy Rotomax good pair with PowerVelocity controller?

Post by Clouse » Jan 23, 2018 11:39 pm

Thank you for the reply. Essentially I'm building a "hyper-miler" vehicle, and I'm interested in setting up my own integrated motor assist https://en.wikipedia.org/wiki/Integrated_Motor_Assist

At my previous job I obtained about 30 lightly used 100A-hr LiFePO cells that were salvaged from a project. I have a vehicle with a 4-cylinder turbo diesel I imported from Canada, I've converted the power steering and water pump to electric, and I am now interested in implementing some sort of low power motor assist to further improve fuel economy (as well as accomplish a few other needs). I currently have a 48VDC (4.8kW-hr) pack of 16 cells built and ready to be installed. I'm now searching for a suitable brushless dc motor (8-15kW) that I can fit in place of my alternator. I can then use the motor to assist the diesel engine and improve fuel economy. I'm also hoping to use it for starting the engine. I'll keep my 12VDC battery for engine and vehicle accessories, and that will be powered by a DC-DC converter from the 48v pack. I'm hoping to use a controller with regen capability so I could charge the 48V pack up if needed on a long trip. Day to day I just plan on charging from the grid.

So that's essentially the idea in a nutshell. I've been doing endless hours of reading and research. For now I've got my eyes on the PowerVelocity controller and possibly a Turnigy motor. Unfortunately I've emailed PowerVelocity twice with questions and haven't gotten any response.

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Re: Turnigy Rotomax good pair with PowerVelocity controller?

Post by amberwolf » Jan 24, 2018 1:40 am

Clouse wrote:
Jan 23, 2018 11:39 pm
At my previous job I obtained about 30 lightly used 100A-hr LiFePO cells that were salvaged from a project.
If those are the blue or yellow (or whatever) plastic bricks with ridges, make sure you build them into a compression pack holder that places appropriate pressure evenly on all sides of the cells, or they may swell up in use, which causes damage between the layers inside.


I'm now searching for a suitable brushless dc motor (8-15kW) that I can fit in place of my alternator. I can then use the motor to assist the diesel engine and improve fuel economy.
Keep in mind that most of these small but high power RC motors can typically only be used at those high power levels while at very high RPM, since most of them are made to drive propellers. At lower RPMs, they'll burn up if used at those high power levels, because tehy're not generating enough BEMF to keep current down. They're also meant to be used with the high-velocity air cooling that comes with the propwash, so you generally need to create a cooling system for them, too, when not used in their original application.

The other problem is eRPM--the electrical RPM, or switching (commutation) speed, at very high RPMs, can be beyond what a controller can do, especially for "ebike" type controllers--the MCUs inside just don't have a high enough clock speed in many cases. Most of them were designed around hubmotors, which with DD versions are very low RPM, around wheelspeed, and even geared versions usually are only around 5x that.


You can get lower RPM motors to do the same power levels, but they are physically larger.


I'm hoping to use a controller with regen capability so I could charge the 48V pack up if needed on a long trip.
As long as the regen current doesn't exceed the normal charging current for the pack it would work. Sometimes regen can be so powerful that it's much higher than the pack's normal charging current, but since regen is usually used for braking, it's only momentary peaks, so it doesnt' make that much difference.

Also, there's something often called EABS that's different than regen, and actually uses up power from the battery to stop the motor--you don't want that mode.

Otherwise, that should be fairly simple, as long as you keep in mind the motor is going to run at a wide range of speeds depending on engine RPM, and the regen voltage (and thus current) you get out of it will vary with that speed. Some of the controllers with regen are adjustable for how much they provide, but not usually on the fly. Some might be, though, if they are adjustable via bluetooth, etc. Might still not be enough to compensate for the RPM range, so you'd have to figure out what that will be and what range of compensation you need to provide to charge the pack at the rate you want.




Unfortunately I've emailed PowerVelocity twice with questions and haven't gotten any response.
He's also a member here, so maybe posting in his sale thread or PMing him might get a response?

Clouse
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Re: Turnigy Rotomax good pair with PowerVelocity controller?

Post by Clouse » Jan 24, 2018 3:57 am

Thanks again for the thorough response! Very appreciated! I'm trying to learn as much as I can and it's great to get feedback from knowledgeable people.
amberwolf wrote:
Jan 24, 2018 1:40 am
If those are the blue or yellow (or whatever) plastic bricks with ridges, make sure you build them into a compression pack holder that places appropriate pressure evenly on all sides of the cells, or they may swell up in use, which causes damage between the layers inside.
Yes they're very similar to Thundersky or whatever those other brands are/were. I don't even recall what brand these are, but they're large cells, at least 100Ah. I still have four packs of 8 cells each that are compressed with plates on either end to prevent swelling/expansion like you mentioned.
Keep in mind that most of these small but high power RC motors can typically only be used at those high power levels while at very high RPM, since most of them are made to drive propellers. At lower RPMs, they'll burn up if used at those high power levels, because tehy're not generating enough BEMF to keep current down. They're also meant to be used with the high-velocity air cooling that comes with the propwash, so you generally need to create a cooling system for them, too, when not used in their original application.
Good to know. I've researched other, likely better suited brushless dc motors (i.e. Motenergy ME0201014201), but they were large and heavy, and just boring... haha. I found the Turnigy and other hobby motors so much more impressive. I also liked that the Turnigy motor was fairly simple to disassemble and work on compared to the other motors I was researching. The Rotomax 150 has a 150kV rating, so to my understanding with my 48v battery pack, that'd put it at a max ~7200 rpm. My diesel engine redlines at ~4500 RPM, so I intended on using a pully on the dc motor that is ~62.5% the size of the crank pulley. That should pair the dc motor with the diesel engine well, but I guess I don't know if the PowerVelocity controller can handle motor speeds that high. I hope to be able to get in touch with them.

I do have a plan for cooling as well; just as you said, they're designed to be cooled in their intended environment.
As long as the regen current doesn't exceed the normal charging current for the pack it would work. Sometimes regen can be so powerful that it's much higher than the pack's normal charging current, but since regen is usually used for braking, it's only momentary peaks, so it doesnt' make that much difference.
I don't recall what the spec is for the charge current on these LiFePo's, but I think it's pretty high. I'm really hoping to be able to use a PowerVelocity controller as the regen strength is programmable on the fly via bluetooth. Their android/ios app is pretty darn cool. It's admittedly a large factor in why I'm so interested in this controller.

Thanks again!

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