One of the hall sensor is not responding

[octomore]

Hi everybody,

I'm testing a 10kW BLDC and I'm using a Kelly Controller (hall sensor control)

One of my hall sensors is stuck in a position (actually state+1 in other words; the hall switch is always on)

The faulty sensor is the one in the middle and 1st and 3rd sensors work just fine.

Due to the design, replacing a sensor is not an option so I'm thinking of replacing Kelly controller to another brand's model which can perform FOC control.

The first question is; I'm thinking of VESC controller or VESC compatible Maytech controller to perform FOC control however I have no experience with these two

brands. Are they good for me?

The second question is about the missing data from the faulty hall sensor; is there any way to imitate the signal of the faulty sensor in the middle by using 1st and

3rd sensors' data? (and any other data retrieved from the controller)

Any help is appreciated

Thanks in advance

 

[fechter]

I'm not aware of any way to "spoof" the missing hall signal based on two working ones. I have seen external encoders that you could possibly use to replace the sensors. Sensorless control on a big motor doesn't have a great track record, but it might possibly work depending on the application. Not good if you want a lot of startup torque from a dead stop.

Can you post a picture of the sensors? There must be some way to replace them.

 

[octomore]

Unfortunately, It is embedded in a polyurethane resin. So we cannot replace it.

Startup torque is not a must and we can cope with the harsh initial movement until the BEMF data is acquired by the controller.

 

[amberwolf]

One of my hall sensors is stuck in a position (actually state+1 in other words; the hall switch is always on)

A switching hall that is on is grounded, usually reading around 0.8v. (these halls are almost always open-collector outputs that ground when active, just being open-circuit whenever they're not active. So a pullup resistor (usually to a 5v source) is inside the controller itself to keep this from floating to an indeterminate state. If the hall is not connected to the controller the controller will see this as stuck off, or 5v (or whatever the pullup voltage is).

Due to the design, replacing a sensor is not an option so I'm thinking of replacing Kelly controller to another brand's model which can perform FOC control.

The first question is; I'm thinking of VESC controller or VESC compatible Maytech controller to perform FOC control however I have no experience with these twobrands. Are they good for me?

I have no way of knowing if any particular brand or controller is "good for you". That would require knowing everything about your project and needs. I don't know the Maytech brand but have seen it in posts around the forum now and then, so you could check those to see if any of them have useful info to you.

VESC in general is a good control platform, and being open-source is customizable if you know coding and need to do that. There are also other open-source projects, some related to VESC, some not, if you are DIY enough to build your own from one of those projecs. Some of them are here in this subforum.

The second question is about the missing data from the faulty hall sensor; is there any way to imitate the signal of the faulty sensor in the middle by using 1st and 3rd sensors' data? (and any other data retrieved from the controller)

There are controllers that can run with a missing hall, presumably by extrapolating a guess of the missing sensor data from the other two, so it's possible to do it--but it does not give accurate position data, so at startup especially under load it may not respond as desired.

The old Grinfineon controller I have can operate this way, but not being FOC it isn't able to monitor phase currents to use that for position data, unlike the Phaserunner I also use. But the PR does not have a mode for partial sensor data--it is either all or nothing--sensorless or not. It does have a sensorless-fallback mode where if the sensors fail it just uses the usual FOC to operate, and sensored-start sensorless-run mode.

 

[harrisonpatm]

Do you have a pic of the motor and/or where the hall sensor is? I ask because I was just able to replace halls on 2 completely different motors that I didn't think I'd be able to replace halls on them.

 

[octomore]

Thanks for the responses...

Sorry for not providing any photos
As I stated, it is sealed under PU resin


I'll try Maytech and let everyone know about the output.