Advice needed on sensorless BLDC model choice

Hi All,

I need to build a model of my present speed control sensorless BLDC system that uses 6-step commutation. It uses bemf zero crossings for speed measurement.The brief motor specs are it is 6 pole-pair 5V with R~=3 ohms and Lm~= 100uh and runs on a 5V bus. The start current is <1A and the run current is only ~30mA. The PWM frequency is about 30kHz. I'm primarily interested in speed jitter as I am looking for somewhere around 30ppm.

Once I complete the first model I want to build a model for the same motor using sensorless FOC.

Do you advise using simscape or should I stick to straight simulink? (I've never used simscape) Can I view phase bemf voltages using simscape or is that hidden from the user?

Thanks,

Answer 1

[Sabin]

Probably best to use Simscape Electrical for control and simulation of electrical systems. The library includes relevant physical systems and multidomain simulation is posible. Also there are control blocks for electrical systems and would allow you to focus on the parts of the workflow that are most important. A good starting point is the BLDC Speed Control example. Back-emf can be visualized in Simscape Results Explorer.

[Brian Tremaine]

Sorry, but the obfuscation of whats going on in the library really goes against my grain. To each their own ...