Why Transformer in KVA?
Answer Posted / omnarayan tiwari
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 ? | 3 Yes | 3 No |
Post New Answer View All Answers
What is a single phase autotransformer?
HOW WE CALCULATE CURRENT IF THERE ARE NOT PRESENT ANY AMMETER OR MULTIMMETER??????
how freewheeling diode improves the powerfactor
In control room of our one plant there is a continuously the incoming power goes to PC is vary,means in stabilizer it continuously indicate from high input to low and low input to high. what is the reason and its solution.
how to select the no. of brushes in a lap winding?
what clearance required for 4.5 mva dry type transformer?
What is the pro & con of having 11kv & 33kv incoming, and what is the adv & disadv. of converting from 11kv to 33kv.
What difference between ref protection and differential protection ?
How do we find the rating of a transformer, if it got burnt badly.
what is frequency response?
75 kw motor take 45 amp in no load delta in star 10 amp but in load it will take 160 amp but IR velue of winding above 500 at 1kw ph to earth and ph to ph. what problem it should be?
Why water bubbles when D.C. Current is passed through it? Why not when A.C. Current is passed?
i installed 100kva ups. what KVA genset they should provid in input side? plz any update formula or ans with reason.
Why the unit sizes of hydro generating machines are not standardized as in case of thermal powerplants?
what is the difference b/w ATS and HTS?