kashew
Electrical
- Jul 16, 2004
- 10
I've been calculating motor starting flicker using the basic formula: LRA x (R cos0 + X sin0)
where cos0 = starting pf and R & X values are in ohms
I've run across a different method of calculation that I'm not familiar with and was wondering if anyone could provide some insight. Is this method more accurate?
The two methods do NOT give the same result.
The formula is:
%Flicker= 1-(sqroot(Zcable*2)/sqroot(Ztransf*2 + Zcable*2))
where *2 represents the value squared
replace Z with R+jX values for cable and transformer
An infinite system bus is assumed.
where cos0 = starting pf and R & X values are in ohms
I've run across a different method of calculation that I'm not familiar with and was wondering if anyone could provide some insight. Is this method more accurate?
The two methods do NOT give the same result.
The formula is:
%Flicker= 1-(sqroot(Zcable*2)/sqroot(Ztransf*2 + Zcable*2))
where *2 represents the value squared
replace Z with R+jX values for cable and transformer
An infinite system bus is assumed.