Table of Contents
Why Generation is 11kV in the power stations?
It is cheaper to generate at a relative lower voltage and then step it up for transmission. Hence, most power generating plants are designed to operate at 11KV. Therefore in order to compensate for this, the primary generation voltage would be; the required nominal voltage + transmission losses.
How does a neutral grounding transformer work?
They let three-phase (delta connected) systems accommodate phase-to-neutral loads by providing a return path for current to a neutral. Grounding transformers are typically used to: Provide a relatively low-impedance path to ground, thereby maintaining the system neutral at or near ground potential.
What conductor is used for 11kV line?
ACSR Conductors
The other types of conductors (mentioned from S. No. 3 to 7 are all ACSR Conductors and are commonly used on 11kv lines, except Dog conductors.
Why is secondary transformer earthed?
The secondary side neutral is grounded so that when an active conductor has a fault that brings it into contact with “earth” (e.g. it touches its metallic enclosure which is earthed), then there is a low resistance return path to the neutral – so that the fault current is sufficiently great the ensure it quickly trips …
What is neutral transformer?
Neutral grounding transformers are a single phase transformer which is used to protect the generator/alternator winding from damaging short circuit. The NGT transformers are just like an instrument transformer whose output voltage is equal to 110 Volts or 220 Volts.
What is the purpose of neutral earthing?
NERs, sometimes called Neutral Grounding Resistors, are used in an AC distribution networks to limit transient overvoltages that flow through the neutral point of a transformer or generator to a safe value during a fault event.
Why is the voltage generated at 11 kV?
The voltage is generated at 11 KV because it requires less insulation in comparison to the generation of voltage at above 11 KV. The high voltage rotating machine may not be so reliable as compared to the low voltage rotating machine.
Why transformer and substation rating is mentioned in 33kV / 11kv/11kv?
Why the transformer and substation rating are mentioned in 33kV / 11kV , 11kV/440V and so on. In case of no load, there may be negligible voltage drop and we may get 110\% (i.e. Sending + 10\% extra which is 11kV) voltage at the receiving point. For this reason, transformer and substation should be rated at full 110\% which is 11kV, 22kV and so on.
Why do we use 11kV instead of 33kV in power generation?
But 11kv, 33kv, 66kv and 110kv are multiple of 11. Reason is to simplify the engineering design. You should know that, designers/engineers thought 11kv is best suited for designing a generater for size of conductor and insulation. Hence, all generation was at 11kv.
What is the voltage ratio of a generator step-up transformer?
Likewise, transmission voltage depends on the standard voltages adopted by a certain country or region. It could be 138 kV, 230 kV, 500 kV in USA or 400 kV in EU or 800 kV in South Africa. The choice of generation voltage and transmission voltage will determine the voltage ratio of the Generator Step-Up transformer.