Answer / nithin shaju

Applying DC power to a transformer will not step up/down
the voltage,since the current reaches its peak within
milliseconds and remain constant.Therefore no induction
happens.So secondary voltage is induced only during the
current growing period (millisec).After that as long as
there is no fluctuation, sec voltage will be 0.
There is no
problem in connecting dc power suppply to a
transformer.Only winding resistance is taken into
account.But if the current is too high there is a chance of
burning the insulation.

Answer / uma

When the transformer is used with dc excitation, flux rises to the point where magnetic saturation occurs, causing a large increase in magnetizing current & overheating of the transformer. therefore they operate in ac.

Answer / venkat

we cannot apply DC power to transformer as it is an ac machine and on applying DC power the windings of the transformer gets short circuited due to unidirectional flow of electric charge

Answer / ahmed

We can apply dc supply to transformer, but here impedance
is only resistance in casof DC.large amount of current will
flow through the promary windings depending on the
magnitude of primary voltage applied.Secondary will not
induce any voltage.

What is the maximum size(MVA)of power transformer available in the India/world?

13 Answers   Adani,

---

what are the values to be accepted on 3 core 185sq mm for 11000volts on insulation resistance between conductors and between conductors and earthed?

3 Answers  

---

How many watts required for single phase power supply?

4 Answers  

---

what is the power factor?please tell me uses.

5 Answers   NTPC,

---

What can a fresh(without experience) electrical engineer contribute to NTPC( Or any PSU company) growth?

3 Answers   NTPC,

---

When color of silica gel will gets change from blue to pink from Top to bottom?

1 Answers  

---

dielectric strength of vacuum is greater than SF6 but for 132Kv uses sf6 breaker & for 33kV uses vaccum breaker why such a contradiction?

2 Answers   MSETCL Maharashtra State Electricity Transmission Co Ltd,

---

In case of 11kV dual delta bank what are the recommended protections with specific CT / VT requirements? The capacitor bank is to be connected to the main 11kV switchgear from where the H.V.Motors and auxiliary 440V loads.

1 Answers  

---

from 33kv to 440v 2mva transformer how much full load current will be at ht side and lt side and which range of ctpt will be used?

1 Answers  

---

what is harmonics?explain in simple words?what is its impact on circuit?

2 Answers  

---

why we use post insulators in no ofstacks at substation for supporting equipment ? why we not use single post insulator

3 Answers  

---

which type of motor is suitable for lift?

18 Answers   NTTF Nettur Technical Training Foundation, Pothigai Power Solutions,

---