Capacitor Switching Transients Calculation
Capacitor Switching Transients Calculation
(OP)
I am plannig to install a capacitor Bank at 69/12.47 kV substation. The bank is 2700 kVAR three stage bank with 900 kVAR in each stages. I am wondering how you estimate the voltage transients due to 900 kVAR capacitor switching?
Substation transformer: 14/20 MVA, Impedance, 9%
Source Impedance (Ohms):
R X
+veSeq, 0.85 6.5
-ve seq, 0.85 6.5
0 Seq, 1.92 11.31
Thanks.
Substation transformer: 14/20 MVA, Impedance, 9%
Source Impedance (Ohms):
R X
+veSeq, 0.85 6.5
-ve seq, 0.85 6.5
0 Seq, 1.92 11.31
Thanks.






RE: Capacitor Switching Transients Calculation
Assuming that your system is Y-grounded, the worst case votlage transient is 2PU. Adding damping into the circuit will determine how fast the transient decays which means the voltage won't reach 2PU.
RE: Capacitor Switching Transients Calculation
Preinsertion resistors can drastically reduce the capacitor switching transients.
RE: Capacitor Switching Transients Calculation
RE: Capacitor Switching Transients Calculation
murli
RE: Capacitor Switching Transients Calculation
To perform a transformer inrush study you would need the data from a B-H curve for the transformer. ATP is probably not the tool for stability studies, one second is a very long time for an ATP study as the time step will usually need to be 100μs or less.
RE: Capacitor Switching Transients Calculation
thanks
RE: Capacitor Switching Transients Calculation
RE: Capacitor Switching Transients Calculation
But, I would not be too terribly interested in going to the University of Idaho. The electrical contractor licensing law there says that I have to prove that I am RICH in order to get a license and by that time I would be making enough money that I would not need to go there.
Virginia, for instance, says that I must have at least $15,000 in net positive assets to get an electrical license to do an electrical project that is worth more than $1,000. They do not want poor people to come in from the Rust Belt and take theri jobs. This is no different than how they one time had a law that said that Catholics could not own land because of how much money Spain and Italy were sending to Vatican Hill.
There are some cities such as Warrensville Heights, Ohio that demand that electricians pay them $150 per year for registration. We do not have quite full blown state licensing in Ohio because itty bitty alleged cities are still allowed to demand tribute from us unlike Massachusetts. Need another year of experience maybe even 6 to get a license in Massachusetts.
Yes, electrical engineering is a political science and politics is a mental illness that revolves around money.
Mike Cole
RE: Capacitor Switching Transients Calculation
Dr K S Smith
Mott-MacDonald, Power Systems Division
Glasgow, Scotland.
RE: Capacitor Switching Transients Calculation
thanks
RE: Capacitor Switching Transients Calculation
Despite one smart aleck response, nothing was said about needing to go to Idaho to take advantage of U of I's engineering outreach program. It is a complete distance learning program means of earning a masters degree without the need to go there to attend classes. They also have a certificate program in Power System Protection.