When using the hall-effect

[jiangfeng]

Hello, dear Daniel

I used the program with hall-effect and sensorless program to drive the same motor with hall-effect,but I found that the sensorless program was better than Hall-effect, smoother and less noise.Besides  the hall-effect program has a smaller speed range .Could you tell me  what to pay attention to when using the program with Hall  to reduce the noise and spin smoother and a lager speed range?Thank you very much 

[Daniel_Popa · Accepted solution]

Hi jiangfeng‌,

Have you bought the motor from NXP as part of a kit?

Most likely the behavior you are seeing is due to the commutation lookup tables sequence. There are 2 commutation tables: clockwise table and counter clockwise table. You can find those under the TrapezoidalControl/CommutationTable Lookup/--right click Explore--

These values assume a specific correlation/interdependency between the motor phases and hall sensors. If those are not set correctly, the motor will still spin but most likely one phase is skipped - or putted in terms of motor control the angle between the stator and rotor magnetic fluxes is not kept at 90deg - basically the effect you are seeing. it's like a car engine running 3 pistons out of 4.

You could try to swap the hall signals and/or motor winding. That would be the simplest approach and you might have some luck and have it working fine.

My advice is to follow the Motor Control Class: Lecture 6 - Commutation and Motor Control Class: Lecture 7 - Commutation Algorithm to learn how to identify the proper hall commutation sequence and how to chance the default commutation look up tables to match your own setup.

Hope this helps! and please let us know if you managed to fix it and how.

Daniel