Load Angle of Synchronous Motor at No Load

[rob1985]

hi all,

Just a quick question, what would the load angle be of a synchronous motor when running at no load. would it be 0 degrees or 45 degrees

 

[phinds]

What do you think and why?

 

[rob1985]

to be honest I am really not sure, I suspect it is zero as there is no load so the magnetic field of the rotor is the same as the stator. am I on the right tracks

 

[phinds]

I agree w/ you, although I'm not sure I'd call it a "load angle" since there's no load

 

[cnh1995]

to be honest I am really not sure, I suspect it is zero as there is no load so the magnetic field of the rotor is the same as the stator. am I on the right tracks

Yes. Active power is proportional to the sine of the load angle. No load, no active power, hence zero load angle.

so the magnetic field of the rotor is the same as the stator

No. You can say rotor magnetic field and stator magnetic field are aligned, or in other words, rotor is aligned with the resultant magnetic field.