Electrical – How do i determine max voltage for a custom BLDC


I would like to know the process that you would go through to determine the voltage rating on a BLDC. I imagine that it has something to do with how the coils are wrapped and the how many coils there are. Any further reading into this, or equations i can use would be appreciated.

Best Answer

Motors use technology with highly technical concepts.

But the basics are heat rise comes from thermal resistance*Pd and ,
Pd = I^2R losses and other losses,
while Voltage and number of pole pairs per Rev determines the RPM,
with no load often rated as kRPM/V.

Torque is max. with current at start with rated V at 100% and has zero torque at no-load full speed. Max rated power is often measured around 82% no-load RPM for linear loads but depends on load, water cooling etc.

I think you should study 1st , buy and compare specs with measured results before you try to design so you can understand what it takes to design.