Can Brushless DC motor work out without controller? 2

[eurasian]

Can anyone tell me about brushless DC pump motor if it is possible to use Brushless DC pump and get DC power directly from battery（use transformer to get AC to DC into Battery for charging as power source) maybe I dont need use inverter anymore, is that possible? I heard that Brushless DC pump must work with a controller to start up? a BLDC pump + a controller would be cheaper than a normal AC pump + a inverter? thank you.

 

[blacksea]

No - you must use a controller for BLDC especially firstly for commutation.
And BLDC pump + a controller would be expensive cheaper than a normal AC pump + a inverter as well.

 

[eurasian]

Thank you Blacksea, that is useful information

 

[eurasian]

Factory tells my customer that they dont need a controller to run the BLDC Pump only if they need to control the speed of the pump, so for coasting down my customer thinks they will change normal ac pump+inverter to just BLDC pump which factory tells them ok that pump can run in full speed without controller, is that true that BLDC pump can work like that? if so why ppl would need controller anymore? since AC pump seems also run in full speed. Can anyone give some advice?

Thank you.

 

[MikeHalloran]

Factory didn't tell customer that there's actually an inverter inside the BLDC motor's shell; that's what does the commutation instead of the brushes.

If we can assume that the internal inverter will age and die at about the same rate as an external inverter or a VFD, then the customer is choosing to regularly replace an entire expensive motor instead of a cheap VFD or external inverter.

On balance, by doing that, they also get a new set of bearings and a new motor well before their individual end of life by doing that. Maybe it makes the customer feel better.

You are in a better position than we are to gauge whether the customer is acting out of ignorance or caution in this matter.


Mike Halloran
Pembroke Pines, FL, USA

 

[eurasian]

Thanks Mike.