Help on brushless motor control

[marcosmelchiori]

I´m intented to use a FET brigde to control a 3 fase DC brushless, sensorless motor. The project must prevent violent load variation on the motor shaft. I´m in a big doubt. What in fact these variations may cause? If my load is suddenly decreased or increased, may any FET be harmmed?

I will aprecciate any help I can get.

thanks.

 

[kinjalgp]

What are the ratings of your motor ?

 

[Phasor]

control a 3 fase DC brushless, sensorless motor

3 Phase DC?? Isn't that a contradiction? Perhaps you mean 3-pole (actually 6-pole, as each pole has an opposing pole)?

 

[marcosmelchiori]

Thanks

I´d like to thank for the interest you´ve decicated do far.

About the 3 phase term, I believe it´s the most widely used term, even though it might seem incorect. It describes a brushless motor wich has three DC inputs, that´s all.

About the motor ratings, here it goes:

Kv = 839
Io = .65
Rm = .112
Kt = 1.722
Km = 5.15

Thanks.

 

[kinjalgp]

It is better to use IGBT insted of FETs or MOSFETs.