why all selected supply voltages are multiple of
11.i.e440,11 kv,33 kv,66 kv,110 kv etc
Answer Posted / dhaval shah
The miss concept is Line voltage is in multiple of 11 due to Form Factor. The form factor of an alternating current waveform (signal) is the ratio of the RMS (Root Mean Square) value to the average value (mathematical mean of absolute values of all points on the waveform). In case of a sinusoidal wave, the form factor is 1.11.
The Main reason is something historical. In olden days when the electricity becomes popular, the people had a misconception that in the transmission line there would be a voltage loss of around 10%. So in order to get 100 at the load point they started sending 110 from supply side. This is the reason. It has nothing to do with form factor (1.11).
Nowadays that thought has changed and we are using 400 V instead of 440 V, or 230 V instead of 220 V.
Also alternators are now available with terminal voltages from 10.5 kV to 15.5 kV so generation in multiples of 11 does not arise. Now a days when, we have voltage correction systems, power factor improving capacitors, which can boost/correct voltage to desired level, we are using the exact voltages like 400KV in spite of 444KV
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
What are the advantages & disadvantages of a group electrive drive?
Explain the different methods used in the choice of rotor slots for reduction of harmonic torques in an induction motor.
I am a electrical engg. diploma holder,applied for junior engineer (electrical),Kolkata RRB. Have I to attend all electrical,mechanical&civil portion in written exam.???
how to select the mpcbs and contactor for 3 phase 30 hp star delta motors.for plc control.and tell me the calaculation for future use.
why T/F winding temp measurement cts are odd secondary current ie,109A/1.2A/1.4A?
how much excitation voltage required to generate 1mw power?
whatis the commertial spec. of distribution boards ?
which type of motor is used in automatic swing gate
Explain how you decide what size of electrical wire do you need?
What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer?
hi, i have 3x200KVA and 2 x 80KVA UPS with battery bank of 150AH 68Nos. and 100AH 204Nos., i need to install AC either ductable or PAC type, so can you help me to calculate heat load and capacity of the AC to install.
Why neutral point is consider as zero potential?
at meter room 50 hrc switch installed,but there are not get earthing proper,so what happen?and 11kv transformer out put going in to hrc main 400a three nog each? so earthing is require for all switch? (some customer made earthing at there home.)
A motor running with lenze frequiency inverter stops if I REDUCE SPEED with 25% load.If I run it in High speed and medium speed running smoothly with full load.please help me to solve it.
Hi Friend I am used multimeter to measure the voltage between R Phase(SS1) to R Phase(SS2). In SS1 is connected with UPS loads. But I am getting voltage between these 2 R Phases. Please give some idea friend