How does frequency affect KVA rating of a transformer?
If a 500 kva, 400 v, 60 hz t/f is to be operated on 50 hz
frequency then how will its KVA rating change?
a-increase
b-decrease
c-remains same
Also explain why do u think like that.
Answer Posted / k r vishnu narayanan
E/f = 4.44*N*phi(max)
E: induced emf
f: frequency
N: number of turns
phi: max flux in the core
When frequency is reduced keeping E constant(at E(max)), flux(phi(max)) has to increase (from eq:)to saturation and harmonics will come into effect. So, there has to be a maximum allowable voltage at a particular frequency and the current too is limited by the saturation effects implying that both V and I has to be limited at a particular frequency (maximum current is always limited by number of turns). Thus their product(kVA) has to be directly proportional to frequency and the answer to this question is b(decrease).
God bless...
Is This Answer Correct ? | 12 Yes | 1 No |
Post New Answer View All Answers
how to calculate transformer turn primary & secondary side 11kv to 420v
dear sir, i completed diploma in electrical in 2005, how i can get electrical supervisor liance in mumbai
pls tell me function of closing coil of A.C.B.
What is state space method ? Why its used ? Can it applicable on linear, non-linear, 1st order, higher order, homogeneous, non-homogeneous, open-loop , closed loops , stable & unstable systems ?
concept of busbar and load dispatching..?
what reactive how to maintain
What is zero of the system?
checking procedure of capacitor based motors.used in fans etc?
WHAT IS THE MEANING OF BALANCED / UNBALANCED IN STABILIZER TYPES.
What do you mean by turns ratio of instrument transformer?
What is voltage divider rule?
What happen if we apply square wave or traiangular waveform voltage to the transformer primary winding instead of sinusoidal wave?
what is the meaning of WYE and DELTA in Electric meter?
WHAT IS THE TOTAL POWER GENERATION IN CHHATTISGARH?
is there any lightning by passer is arranged in ship like buildings?