Phase Amps VS battery Amps, mosfet controller

[yabert]

high pA

Ummm! can you elaborate on that?

 

[A-DamW]

Ummm! can you elaborate on that?

pA = Phase Amps

 

[yabert]

Haha! That was an easy one.
Thanks

 

[yabert]

Let say I ask you, smart people, what controller for my application:
Large boat at low speed, Leaf motor (water cooled like the controller), large 58V (16S NMC) 160 kWh battery, 10-15 kW max continuous, peak 15 kW.

-3shulmotors C700 at 680$usd
-Nucular 24 fet at 610$usd
-VESC 75/300 at 400$usd
-ASI BAC 8000 at 700$usd
-Golden motor EZ-C481200 at 580$usd
-Far-driver ND721200 at 580$usd
-Flipsky FSESC 75450 at 280$

 

[yabert]

From my search (please let me know if wrong):
-Golden motor, Flipsky and Far-driver are low cost Chinese with questionable reliability
-3 shul have a laughable 3 months warranty (who can offer such short term warranty? I bet it's better than false warranty)
-ASI BAC have proprietary complex software and have high price, so...
-VESC 75/300 is awesome, open source and nice soft. I'm fan, but power is limited
-Nucular seem to have tricky soft/programing, but it look like my best bet for my project.

 

[pwd]

Incase you did not know; 3shul is VESC based and can be programmed with VESC tool. I've been using a CL700 for a couple years and it has been working well.

 

[yabert]

3shul is VESC based and can be programmed with VESC tool

Yes, like the Flipsky and Go-FOC from MakerX.
The VESC tool look awesome and it's why I'm so hesitant to go strait with the Nucular. I would highly prefer a controller with VESC tool.
Sure 3shul seem nice and use VESC tool, but man, 3 months warranty

 

[scianiac]

I can see reasons why any VESC mfg would want short or no warranties, VESC due to it's expansive settings has some user issues. Lots of settings means you can run a wide range of motors and tune it well to suit most any motor but that also means if you don't know what you are doing (or even if you do but you get careless or complacent, been there done that) you can blow up controllers. Not saying you can blow up other controllers with incorrect settings too. Overall from what I've seen I would say 3shul is decent but not top shelf hardware wise and low end but not the worst support wise.

There are a few other high power VESCs out there but they are very niche and so come with a high cost, like a team tri-force or a SevenEV.

I have been experimenting with using very cheap VESC hardware (flipsky/makerbase) with encoders. One of the hardest part of any controller is the sensorless part, you have to know what you are doing to design good hardware that is noise free and flipsky don't know what they are doing. Designing hardware that can handle hundreds of amps is still not what I would call easy but is easier. So if you use an encoder for the full RPM range you just kinda cut out all the sensorless part. You're still using the current sensing to control the current but that can tolerate more noise than trying to figure out the motor position. Still not sure if it's really worth it vs going with better hardware.

 

[yabert]

Great input scianiac.
Thanks. Fully pertinent.

One of the hardest part of any controller is the sensorless part

Do this mean it's highly preferable to use the resolver of the leaf motor in order to reduce noise and potential problem to the controller?
Clearly, for a boat propeller, I wasn't really interested to debug the link between resolver and controller and simply run sensorless all the time.

 

[scianiac]

I mean if your controller supports the resolve yeah it will be better, but you may have no issue at all running sensorless, it depends on many factors like the controller and motor. Although in a boat many of the sensorless issues are avoided. I would first try it sensorless and only keep the resolver as a backup option. My point was a low quality controller may be less happy running in sensorless, if I recall IPM motors like the leaf can be a little harder to run in sensorless. Still a controller with decent hardware should be able to do it.

Also for efficiency you should aim for a controller that supports MTPA. A leaf motor being an IPM motor will be very salient and therefore will probably operate more efficiently with MTPA, I say probably because the motor is oversized enough that the optimal efficiency may be somewhere in the middle, maybe the motor will actuall be at "low" load for how it was designed. Hard to say but having the option you could so you could test it would be nice.

 

[mxlemming]

From my search (please let me know if wrong):
-Golden motor, Flipsky and Far-driver are low cost Chinese with questionable reliability
-3 shul have a laughable 3 months warranty (who can offer such short term warranty? I bet it's better than false warranty)
-ASI BAC have proprietary complex software and have high price, so...
-VESC 75/300 is awesome, open source and nice soft. I'm fan, but power is limited
-Nucular seem to have tricky soft/programing, but it look like my best bet for my project.

I design controllers so I avoid recommending or giving a preference because it seems unfair...

I will say though:
1)MTPA on that motor isn't nice to have, it's essential.

2) Regarding sensorless... Don't fall into this trap. There's good reason for sensorless existing for cost optimisation and backup against sensor failure but you can spend months failing to make sensorless work fully. The faster you get an encoder in there (resolvers are a right pain) the less trouble you'll have. I say this as the author of one of the VESC observer options... Just get an encoder and save a world of irritation or unrealised lost efficiency.

 

[yabert]

Awesome information guys. Thanks for that.
I have to learn quite a bit to reach my goal of a reliable project and it's with help like that I will be able to do it.

Just get an encoder

Something like nucular sell on their web site? Other suggestion?
Based on nucular video, it seem that someone already fit this encoder on a Leaf motor.

 

[mxlemming]

Awesome information guys. Thanks for that.
I have to learn quite a bit to reach my goal of a reliable project and it's with help like that I will be able to do it.

Something like nucular sell on their web site? Other suggestion?
Based on nucular video, it seem that someone already fit this encoder on a Leaf motor.

View attachment 369991

That kind of thing yes. Nothing obviously wrong with the nucular encoder. It will probably work with whatever controller you have.

 

[scianiac]

Interesting, I was curious what encoder the Nucular uses, it's an MT6816 but appears to be only set to operate in ABZ mode instead of SPI. I'm not really sure exactly what all the pros and cons of ABZ vs SPI, kinda assume they both require a solid connection to avoid noise and such. I guess SPI tells the controller where the motors is from the start while ABZ waits a little to send the index position even though the chip knows where the rotor is regardless. ABZ is probably much more supported though and differences are mostly irrelevant differences in real world use.

Just glancing through the magntek site though has answered something I've been wondering about for awhile, magnetic encoders for motors with no end shaft. I guess the term I was missing when looking was off-axis, seems like an interesting solution to fit an encoder to a hub motor.

 

[yabert]

Nothing obviously wrong with the nucular encoder. It will probably work with whatever controller you have.

Sure, but let say I don't buy Nucular. Where I can find a quality encoder to do this kind of job?

 

[bananu7]

Sure, but let say I don't buy Nucular. Where I can find a quality encoder to do this kind of job?

You can buy a $2 breakout board for AS5600 hall effect sensor and stick it on the cover (and a magnet on the rotor) and that's pretty much it, it's a single-chip solution.

 

[mxlemming]

You can buy a $2 breakout board for AS5600 hall effect sensor and stick it on the cover (and a magnet on the rotor) and that's pretty much it, it's a single-chip solution.

I don't think as5600 is much good for this. I2c and low speed analog/pwm. Get mt6816 or similar

 

[j bjork]

3shul has an encoder too, I dont know if it is good or not.

 

[yabert]

Thanks all for those great info.