I've been having trouble with a submersible pump that we buy from China in bulk. The pumps are fine, but the BLDC controllers that they come with regularly die costing me a service call, flights, hotels, etc. Instead of doing a redesign replacing the pump, I had the idea to just replace the BLDC motor controller with something that WASN'T from China... so I bought a VESC. Overkill, I know. But I just wanted something that was super flexible for me to start experimenting with. The existing controllers run the pump anytime you put 24VDC on them. I'd eventually like to find a configuration for that, but at the moment that's not the problem.
The pump and motor are submersible magnetic drive units and have 3 wires for input power. They claim to be BLDC so I thought it wouldn't be that hard to hook one up and get it to run with a VESC. It's proving to be more difficult than that. I think it's just because the motor is so far outside of typical motor parameters that it's having trouble finding setting that work.
Data sheet BLDC Pump - DC50F-24150S.pdf
Basically an in-runner with a single cylindrical magnet at the core.
When running the Setup Motor Wizard, I'll choose "Small In-runner", and Run Detection. This is what comes back-
VESC ID : 10
Motor current : 8.01 A
Motor R : 389.20 mΩ
Motor L : 268.85 µH
Motor Flux Linkage : 4.80 mWb
Temp Comp : False
Sensors : SensorlessDuring the detection, I can get a little cogging, and eventually I think it turns over a few times. Then after I'll try to run it manually, and nothing seems to get it to actually turn over. I'm running this from a benchop power supply that will current-limit at 5A. The pumps typically only pull 2-3 A depending on load, however, the VESC appears to want to drive them a lot harder (~)8A). However, I'm typically getting only .050 to 3A draw indicated on the power supply.
I've been through FOC and BLDC setup, and haven't been able to make it move any water. Any help would be appreciated.
Thanks!
Detection parameters look wrong. There should be a magnet pair inside, so a 1 pole pair motor. You can try and do a manual detection (left menu, Motor Settings, FOC) There you can adjust the motor current for detection, the duty cycle and the ERPMs ( electrical RPMs) used for detection. Amp flow from the battery differs from Amp flow towards the motor. At 50% duty cycle the motor sees twice as many amps as the battery provides, but it runs at half the battery voltage. So power in and power out are still the same. You can try to detect it with 5A and play with ERPMs a bit. In your case ERPM and RPM is the same. The default of 2000K is maybe therefore a bit high for detection.
Please also make sure to use the latest beta VESC-Tool: https://vesc-project.com/node/2859
This new VESC-Tool should be a lot better in detection motors.
The other question: What is your VESC hardware?
Frank,
Thanks for the quick response!
My hardware is a newly purchased VESC-6 Mk V
I just downloaded the VESC tool, and have flashed the latest firmware.
I'll give it a shot right now.
A couple results to share-
In the VESC tool, Motor Poles has a lower limit of 2. It's set to 2.
If I set currently to 5.0 A, D: .50, and wto 1000 ERPM/s, I get "Bad Detection Result... Could not measure flux linkage properly. Adjust the start parameters... and trying again"
Here's a picture of the motor. As you can see, the in-runner magnet is a single piece.
Should I hook a scope up to a working BLDC controller + Pump and post the results?
Have a look if it is diametrically magnetized. One half circle is NORTH, other half circle SOUTH. Try the wizard again, but new VESC tool.
You can also try BLDC mode. FOC should also work with some tweaking.
I wasn't expecting this... but here's what I found by using another magnet. (btw, N and S may be reversed)
I'm running VESC Tool 3.0. Just downloaded it yesterday. Is there a later one I should be using?
So that behaves like a 2 pole pair, 4 magnet motor. RPM is ERPM / 2. Make sure you use this VESC-Tool and update the firmware. https://vesc-project.com/node/2859
Try to use low ERPM settings during detection and see if it eventually starts spinning during detection. Also try low Amp values and work your way up. If you saturate the stator with too many amps, detection is not possible. Lets see if the Wizard works. If not try manual detection and play with the parameters a bit. Detection works with FOC open loop, creationg a rotationg magnetic field without tracking the rotor. The rotating field will allow the magnets to follow it. So the motor has to turn during detection. The VESC will ramp up the erpm, allowing the magnets to follow at some point. You can try 500ERPM and see if that makes the motor spin during detection with 3A and D:0.3.