Fault Level of Sub Station in India

350 MVA for 33kv

650 MVA for 66 kV

and so on. Refer CBIP publication 256/145 etc. or Technical Report No. 9

Can u please tell me from where i can get this publication or can u send me the data if u have

Here is the better figures obtained from CBIP.

415V 50KA

3.3kV 40KA

6.6kV 500 MVA

11kV 750 MVA

33kV 1500 MVA

66kV 2500 MVA

132kV 5000 MVA

220kV 10,000 MVA

Figures given in previous comment shall be replaced by the above.

according to me the fault level depends on the No. of generating station, transmmition line. so, how can we decided from transformer ratting ?

You know transformer limits fault current also?

i have no more idea.but i know only that we can find transformer current limit by its rating(KVA) and its voltage level.please reply me.

Impedance restricts the fault current.

please give me idea about fault level calculation.

According to this figure at 132 kV fault current comes out to be 21.86 kA, but in realilty there are switchgears of rating more than this value! How come? Pl clarify

Thank you very much @biswansth.das

The data is very informative.

Could you please provide me with that single sheet of paper from the publication.

I would be highly obliged if you could help me in this regard.

Normally fault level depens on the client requirment. A 33 kV System can be designed for 31.5 kA , a 132 kV System is designed for 40 kA with highest fault current for the transformer is considered.

220 kV GIS systems are designed with a fault current of 50 kA.

The other important aspect is the time in secs for the fault current. Again 40 kA for 1 sec is designed for Transformer used in the 132 kV System. 50 kA for 1 se for 220 kV System and 31,5 kA for 3 secs are designed.

As I empahsised it depend upon theclient requirement and the important equiment like Transformers are designed for highest levwel of fault current.

A 400 kV System is also designed for 40 kA for 1 sec.

This is based on the practical application being implemented in at the projects.

Regards,

N.Suresh

I am having a transformer of 2500KVA with impedence 6.75%, I want to take independent feeder from electricity supply co.'s sub station (66KV). the line voltage will be 11kv, I just wanted to know the fault level of 66KV sub-station(If any standard guidelines in Haryana or India), so that i can select the VCB and HT cable size

Dear friend,

The CBIP norms are considered for any design basis in India. For 11 kV feeder fault level must be equal or less than your transformer SC fault current level.

Regards,

N.Suresh

A possible guide to maximum 11kV Fault level is that if the 2.5MVA transformer is assumed to be on infinite 66kV bus bars, then the maximum fault level at the substation 11kV bus will be 2.5MVA divided by %Z.

THerefore the maximum fault level at 11kV will be 2.5 divided by 0,0675 (pu) = 37.037MVA. Corresponding to 1.94kA.

juke

The Fault lvel in india is considered as 350 MVA.

No, it always not as per client's requirement. The type test for the particular fault should be done from recognised laboratory. Standard fault level switchgear is available in market, you have to design your system as per the availability. Anything special will cost money and time, thereby delaying the project.

Dear sir ,

In India all state electricity board Fault Level of Sub Station i want know please help me where can i get from standard data.

reagrds

swamy