Capacitors on the transmission system

[donkeyboy]

What considerations do we have to take into account when recommending capacitors to improve loss on the transmission system? Where should be place them? What size would be safe to avoid harmonics? etc.. Thanks

 

[davidbeach]

There is far more to it than can be reasonably or safely answered here. Your best bet would be to hire someone locally who is familiar with that type of design to consult for you.

 

[jdyee]

Depend on your system criteria. You should check capacitor switching capability, size, harmonics, loss saving, reactive reserve (PV-QV curve), delta V (for switching capability), expandable rack size for the future expansion... Depend on what type of capacitors and what your purpose of using these capacitors you can determine where to place them. For example, a switch shunt capacitor usually is placed in a substation and it is connected to a bus. A series capacitor can be placed on a line...

 

[00123456]

Mr.Donkyboy!!!!
Are you talking about series compensated line?

Thanks

 

[Bahram7]

The idea behind using capacitor banks to decrease transmission losses is to avoid transporting MVARS over long transmission lines and thus reduce the line current and consequently RI¨2 losses. Normally these capacitors are located at the receiving-end of the long line. I've seen up to 500 MVARS bank on 500 kV transmission systems in the west-coast.

Bahram7

http://www.Simtech-Intl.com

 

[cuky2000]

Capacitor banks supply VARs and boost voltage. They are connected either shunt or in series, depending upon their function. Shunt capacitor banks are used to boost local voltage and/or to improve load power factors. Series capacitors are primarily installed to increase power transfer capability and improve stability limit by compensating for line reactance. They make the same line seem to be electrically “shorter”

Usually series capacitors could be installed at line terminals, two capacitors at 1/3 and 2/3 of the line or one capacitor placed in the middle of the line

Harmonic may have negative impact but usually is not a major problem on transmission systems. Higher short circuit currents and Sub-synchronous resonance issues may be a concern to be addressed. Reactors and power system stabilizers at generators could be used as a mitigating strategy.

 

[donkeyboy]

sorry for the confusions. I was talking about shunt capacitors. Where can I find the best resource to estimate the harmonics affect, the negative impact of higher short circuit currents and Sub-synchronous resonance issues a capacitor has on the system so that we do not oversize the capacitors and cause those negative impact on the system.