Capacitor Bank on Primary vs Secondary?
Capacitor Bank on Primary vs Secondary?
(OP)
I have a question regarding placing a capacitor bank on the primary high side (transmission level) or on the secondary side (distribution) and relating this to the transformer tap regulation.
Is it beneficial to place a cap bank on the high side of the transformer? Since you have better voltage regulation (approx 5%) on the secondary side where the transformer tap would move less and prolong the life of the transformer?
Or does putting the cap bank on the secondary side of the transformer would cause the transformer tap on the high side of the transformer to move a lot which would degrade the life of the transformer. The reason for tap movement is to regulate the voltage level on the secondary side that may have a load factor of 60% ?
Any insights?
Many thanks
Is it beneficial to place a cap bank on the high side of the transformer? Since you have better voltage regulation (approx 5%) on the secondary side where the transformer tap would move less and prolong the life of the transformer?
Or does putting the cap bank on the secondary side of the transformer would cause the transformer tap on the high side of the transformer to move a lot which would degrade the life of the transformer. The reason for tap movement is to regulate the voltage level on the secondary side that may have a load factor of 60% ?
Any insights?
Many thanks






RE: Capacitor Bank on Primary vs Secondary?
RE: Capacitor Bank on Primary vs Secondary?
So what is the need for the capacitors? Distribution or Transmission?
In general it's better to place capacitors close to the location needing correction.
RE: Capacitor Bank on Primary vs Secondary?
RE: Capacitor Bank on Primary vs Secondary?
Regards
Marmite
RE: Capacitor Bank on Primary vs Secondary?
Marmit is absolutely right. It will definitely be cheaper to install it on the secondary side. That is why I am considering it; however, I am worried about the transformer tap moving to often due to the nature of the load (daily load going from light load conditions say 5MW up to 12MW) and due to the fixed capbank on the low side which may result in more tap movement due to the low side regulation. This may increase exposure to transformer damage which may in turn cost even more in the future. Is this second paragraph I wrote true?
RE: Capacitor Bank on Primary vs Secondary?
What about MVAr load oscillations? In general, for wide load oscillations, fixed banks are bad solution. Eventually you can cover lower demands with fixed banks and let higher demands uncompensated. If you go above that, you are risking overcompensation and over voltages during low demands. Again, it seems to me that load oscillations magnitude will have key influence on tap changing frequency, not cap bank itself. However, the question isn't so simple, typical load diagram, transformer and switchgear data will help for more accurate answer.