Distribution73
Electrical
- Mar 18, 2015
- 40
Hello,
I am trying to select a suitable S.A. for a 245kV substation. After going through ABB and Siemens papers on S.A. selection one of the main hilighted factors for the selection is the "lightning intensity" of the area. However I haven´t been able to find any reference defining what is considered low, normal, high or very high lightning intensity. That is, how many discharges/year/km2 are considered low, normal, high, very ghigh intensity.
In our case we have a keraunic level of 40-50 discharges/km2/year. Based on our system levels, I have come to the conclusion that we could choose 10 kA, Class 3 SAs or 20kA, Class 4 SAs. I have found commercial S.As for both specs that provide an adequate protective margin considering the BIL of the substation switchgear, however I wouldn´t like to overspecify things or at least have a reason to choose one or another, based on the keraunic level.
Any feedback is much appreciated.
Thank you
Fernando
I am trying to select a suitable S.A. for a 245kV substation. After going through ABB and Siemens papers on S.A. selection one of the main hilighted factors for the selection is the "lightning intensity" of the area. However I haven´t been able to find any reference defining what is considered low, normal, high or very high lightning intensity. That is, how many discharges/year/km2 are considered low, normal, high, very ghigh intensity.
In our case we have a keraunic level of 40-50 discharges/km2/year. Based on our system levels, I have come to the conclusion that we could choose 10 kA, Class 3 SAs or 20kA, Class 4 SAs. I have found commercial S.As for both specs that provide an adequate protective margin considering the BIL of the substation switchgear, however I wouldn´t like to overspecify things or at least have a reason to choose one or another, based on the keraunic level.
Any feedback is much appreciated.
Thank you
Fernando