Find transformer efficiency for 11 Kv rating?

Replies

• 

  narayana murthy

  fully loaded means it has high current taking so check for the output power and input power as it is a.c and it is transformer it will have frequency of 50hz.
  power=vicos(phi)
  efficiency=output power/input power
  so u can find efficiency at what ever rating is
• 

  aarthivg

  narayana murthy

  fully loaded means it has high current taking so check for the output power and input power as it is a.c and it is transformer it will have frequency of 50hz.
  power=vicos(phi)
  efficiency=output power/input power
  so u can find efficiency at what ever rating is

• 

  aarthivg

  is it possible to overload transformer up to 150 percent?
• 

  narayana murthy

  ofcourse depending on rating and losses will be heavy in such case magnetic saturation also occurs here
• 

  aarthivg

  narayana murthy

  ofcourse depending on rating and losses will be heavy in such case magnetic saturation also occurs here

  Is it a feasible system if we overload a transformer up to 150 percent for certain period of time and then allowing it to share the load with a another transformer by parallel operation
• 

  narayana murthy

  as per my knowledge it should not overloaded to such extent
  @other ceans: correct me if i am wrong
• 

  lal

  Usually electrical devices are designed to work at an overloaded condition without break down. That is a transformer or motor or any AC machine (except fuses and CBs😁 ) can withstand a power surge that is beyond the rated value. The device continue to work perfectly without damage at power above rated value. This is to prevent the possible damages that can occur when a fault happens in the circuit.
  But, the over power, that the machine can withstand without damage depends solely on the design and operating conditions which is based on its applications. A transformer can withstand a lot more power capacity if extra cooling techniques are employed. Factors like insulation breakdown and so on should also be considered while doing so.
• 

  narayana murthy

  i think lal u missed one thing surges are only for fraction of second but here topic is about overloading for some considered time.
  there is a problem here at such condition overload makes breakdown of insulation and there is a problem of magnetic saturation as current increases flux increases leads to magnetic saturation
• 

  lal

  I think, the surge that you mentioned is lightning surge and faults friend. I wrongly used the word 'surge' there 😁 My intention was to mean 'an increase'.
  By the way, overload wont induce a breakdown. If the voltage increases beyond the maximum withstand-able value of insulation, it happens. Over load will cause large increase in temperature that would lead to damage of machine if proper cooling methods are not used. And there would be magnetic saturation problems. But machines are designed to work at more than hundred percent of the ratings.
• 

  narayana murthy

  may be lal so we can conclude that this is suitable for over loading???
• 

  aarthivg

  lal

  I think, the surge that you mentioned is lightning surge and faults friend. I wrongly used the word 'surge' there 😁 My intention was to mean 'an increase'.
  By the way, overload wont induce a breakdown. If the voltage increases beyond the maximum withstand-able value of insulation, it happens. Over load will cause large increase in temperature that would lead to damage of machine if proper cooling methods are not used. And there would be magnetic saturation problems. But machines are designed to work at more than hundred percent of the ratings.

  do you mean to say, overload does not cause insulation failure?
• 

  lal

  Sorry to be late back here..
  I meant, overloading won't induce an insulation breakdown. But it can cause insulator damage by increase in temperature.
  @nm, yeah with suitable cooling techniques, a transformer can be overloaded.
• 

  aarthivg

  lal

  Sorry to be late back here..
  I meant, overloading won't induce an insulation breakdown. But it can cause insulator damage by increase in temperature.
  @nm, yeah with suitable cooling techniques, a transformer can be overloaded.

  is it feasible to overload a transformer
• 

  lal

  I am not quite sure about that buddy. Will try to find out more 😀
• 

  aarthivg

  lal

  I am not quite sure about that buddy. Will try to find out more 😀

  ok. thanks
• 

  narayana murthy

  actually overloading causes high temperatures due to increase in losses but according to me it shouldn't be overloaded but in some conditions situations demands at such time we can use answer given by lal
• 

  aarthivg

  narayana murthy

  actually overloading causes high temperatures due to increase in losses but according to me it shouldn't be overloaded but in some conditions situations demands at such time we can use answer given by lal

  just consider this scenario. there are 2 transformer connected in parallel let it be t1 and t2. during flat period, t1 operates, and t2 is in off position. when the demand increases, transformer t1 is overloaded up to 150 % for some time. and then t2 is switched on.so that load is shared between them as 75 %. this eliminates no load losses and bus fault current. is it a feasible idea?
• 

  narayana murthy

  aarthivg

  just consider this scenario. there are 2 transformer connected in parallel let it be t1 and t2. during flat period, t1 operates, and t2 is in off position. when the demand increases, transformer t1 is overloaded up to 150 % for some time. and then t2 is switched on.so that load is shared between them as 75 %. this eliminates no load losses and bus fault current. is it a feasible idea?

  yes ofcourse
• 

  aarthivg

  narayana murthy

  yes ofcourse

  i have planned to do project on this basis.
• 

  narayana murthy

  aarthivg

  i have planned to do project on this basis.

  nice then please give your progress
• 

  aarthivg

  aarthivg

  just consider this scenario. there are 2 transformer connected in parallel let it be t1 and t2. during flat period, t1 operates, and t2 is in off position. when the demand increases, transformer t1 is overloaded up to 150 % for some time. and then t2 is switched on.so that load is shared between them as 75 %. this eliminates no load losses and bus fault current. is it a feasible idea?

  At last this idea end up successfully. Thanks to all
  It has been forwarded to tneb.