Cap Bank for Volt Regulation 1

[Samuel2500]

I have a switched 2-step Cap Bank on the LV side of the distribution network. Now i am looking to co-ordinate the transformer tap changing and the switching of the capacitor bank for the purpose of voltage regulation.

I understand that VR is not the primary purpose of a CapB, however as switching it in/out can adjust voltage levels.

Now i have come across a few different formulas for calculating the resulting voltage rise from the application of a Capacitor bank. I was wondering which it is, either:

delta V = (kVAr / 10* kV^2) * Xl

or

delta V = (Bank kVAr / KVAsc)

where KVAsc = Transf KVA / Transf per unit impedance.


Also, you can calculate the voltage rise/drop in a transformer because of the application of the capacitor bank. I was wondering what does this actually mean? If i had a 33kV/11kV system, and im regulating the LV side. Is it implying that adding the capacitor will have an additional voltage rise through the transformer? (?!)

 

[wareagle]

I thought it was Ixc x XL x 1.73 which come close to this example. Here is some good information.

http://www.gilbertelectrical.com/library/technical.discussions/economics/economic_benefits.htm

 

[rbulsara]

Good link wareagle. (Assuming formule therein are correct.)

Rafiq Bulsara

http://www.srengineersct.com