Why Transformer in KVA?
Answer Posted / arvind singh
kVA is the unit for apparent power. Apparent power consists
of active and reactive power. Active power is the share of
the apparent power which transmits energy from the source
(generator) to the user. Reactive power is the share of the
apparent power which represents a useless oscillation of
energy from the source to the user and back again. It
occurs when on account of some »inertia« in the system
there is a phase shift between voltage and current. This
means that the current does not change polarity synchronous
with the voltage. But the heat generated in a winding as
well as the eddy current losses generated in a transformer
core depend on the current only, regardless of whether it
aligns with the voltage or not. Therefore the heat is
always proportional to the square of the current amplitude,
irrespective of the phase angle (the shift between voltage
and current). So a transformer has to be rated (and
selected) by apparent power.
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
A powerplant has 8 gensets operating in grid parallel mode. In one genset sometimes there is pf variation and kvar variation. The plant operates in pf mode. When this variation is observed the load is stable, voltage is also stable, freq and genset speed is also stable. How will you check the functioning of pf card. What shall be the ideal output vdc of the pfc, from there it is input to AVR?
1sq mm dc powr cable can carry how much dc currnt
how you will decide the distance between the power transformer and its fencing
plz explain the auot-reclosing circuit in electrical engineeing
Difference between low impedance and high impedance Restricted Earth Fault
what is the common earth
what type of questions are asked and howmwny questions belong this catagory?
What is the basis for selecting Vk/2 or Vk/4 for REF and Differential protection of Transformer and What is the significance of magnetising current
in indoor type circuit breakers why only the corner breaker trips specially during cold season. What is the reason.
Its possible to use 3core 2R of 240 sq.mm cable for 3phases & separely 50sq.mm 3core cable fully for Neutral for connection of PCC to MCC 3ph..4wire system?
defination of transistor controlled series capacitor
What tests should i carry over on a newly rewinded DC Generator with voltage rating of 38 volts and current rating of 350 amps, to certify that the machine is OK?
for a 500 KVA connected load, I calculated 30% of capactor for power correction. Even after using 225 KVR capactor PF is not improving. What could be reason for low Phase correction factor?
What is Fire Panel ? How it works ?
Dear all, i completed M.E(Power Electronics & Drives) 2011 passed out having 78% so i need job in core side but i don't know how can i receive the calls from electrical companies and i uploaded my CV in naukri, times jobs etc.. In that iam not recieved any mails from good companies so give me best procedure plzzzzzzzzzzzzzzzzzzzzzzzz..... Thanks, K.Linga Reddy Email-id:-lingareddykmthm@gmail.com Ph no:-08015402078