Baserunner settings for unknown Shengyi geared hub motor

[pickworthi]

I have a kit from Dillenger installed on my bike. It's this one:
https://dillengerelectricbikes.co.uk/collections/street-legal-kits/products/street-legal-electric-bike-kit-samsung-powered-v2

It is now almost four years old, and while it is serving me well, I have decided that I want to start a piecemeal upgrade, starting with a move to a Cycle Analyst V3 and Baserunner_Z9 from Grin. This means that I need to know a few basic parameters for the Baserunner setup, and is the reason for asking the question here. I've done many searches and read many threads, and although some people have posted information close to my needs, I can't find a close enough match to be confident I've got this right. So, thank you in advance for any help.

The motor has one long identifier printed on its case: SY739700CRL0987YS1
That makes it a Shengyi model. I wrote to Dillenger as the OEM, and asked for the model number, or the KV and max phase current - they declined to give me any information about the motor.

Having opened it up (picture of motor below), I can assert the following:
- The gearing is: Ring gear 78 teeth, Planet gears x 3 @ 30 teeth each on a freewheel clutch plate, Sun gear 18 teeth.
That makes the reduction ratio 4.33(recurring):1
- There are 20 magnets on the outer motor casing.
- There are 18 windings (not sure of terminology here - bits with wire wrapped around them )

To set up a Baserunner, I need 1)the motor’s kV in RPM/V, 2)the number of pole pairs in the motor and 3)the maximum phase current

For RPM/V: I've looked at Grin's geared hub motors, and their SX1 is a close-ish match to my motor. The SX1 is 7.4 RPM/V, the documentation says a guess is OK, so I'm assuming that would be as good a guess as any.

For the number of pole pairs, the Grin documentation says " in a geared motor you need to multiply the magnet pairs by the gear ratio". This is where I get unsure. As I said above, there are 20 discrete magnets. So 10 magnet pairs?
And that then makes 40.33... poles? Do I enter the accurate fraction, or just 40? If this is supposed to allow the Baserunner to work out how fast the wheel is turning, rounding this down seems to be introducing an error. So - this is the main thing I am unsure about.

For the maximum phase current, looking at several threads on this forum, for 36V systems like mine, there seems to be a common theme of around 30 amps being a sensible maximum for a hub motor. Is there a safe-ish way to test out a suitable maximum for this motor? Alternatively, if I set the Baserunner maximum high, and then set the Cycle Analyst to limit power at 500 watts, would that be a good approach?

I would be very grateful for any guidance from people who have already travelled this path. Any input appreciated.

 

[qwerkus]

[...]

Looks like a fairly standart 10poles geared hub.
Autotune doesn't work ? That should give you R and L first, and after the spinning test the right Kv. Internal reduction calculation seems correct, though it is only useful if you do not use an external speed sensor (and your motor doesn't come with a dedicated one), that would also mean no speed signal when the motor doesn't spin. 30A max phase amps should be fine. phase amp is between 3/2 to 2/1 the max battery current you want to feed you motor, and given it's size, 15A seems reasonable. That's 630W at full battery load. Maybe you can push to 700-800 without stripping the gears, though certainly not for more than a few minutes.

 

[pickworthi]

I have now got my Baserunner and Cycle Analyst installed, and managed to get past the autotune routine:
- guessed 7 RPM/V
- Pole count of 43 (1:4.3 ratio, 20 magnets = 10 pairs)

To my total surprise, it worked, even spun the motor the correct direction first time.

When done, the PC Phaserunner application reported thus:
- Kv = 7.35 RPM/V
- Rs = 99.9 mOhms
- Ls = 194.0 uH
- Standard Bafang hall sensor pattern detected
- Motor position sensor type = Hall sensor start and sensorless run

Taking it out for a few test rides, I noticed quite a lot of a "sh-sh-sh-sh" noise when not quite at full power. With a battery that sustained 40V+ under load this progressed to some shuddering.

I noticed that the tool tip comment for PPL Bandwith said "... geared hub motor ... where RPM can change suddenly ...,. you will often need higher values (upwards of 250-1000 rads) in order to prevent instantaneous overcurrent fault errors ..."
The default value provided by the app is 151 rads.
I changed that to 500 rads and the noise and shuddering went away.

Since I am firmly in the "don't understand what I'm doing here" category, I have a few questions where I would appreciate some insight:

1) I tried setting the motor position sensor type to "Hall only". When I ran autotune, the app changed it back to Hall start and sensorless run. Should I just set it to "Hall only" after running autotune? Is there a "best" option?

2) My PPL bandwith setting of 500 rads is just a guess. I don't know what "rad" refers to here - I'm guessing not "absorbed unit of radiation energy". Is there a way to work out what would be an appropriate value, and does setting it really high have any downside?

3) I left PPL damping at 1.95. Tool tip just says what it is (damping on phase locked loop motor RPM tracking). If I set PPL bandwith higher, should I nudge this up as well? Or leave well alone?

4) Current Regulation Bandwidth defaults to 1500 rads. The tool tip says "For motors with low winding impedance, it's often necessary to increase the regulator bandwith to prevent phase overcurrent faults". Is there enough information here to determine if this motor needs a higher (or lower) setting? Does it matter?

Many thanks in advance for your patience with the newbie questions.