What is the primary purpose of capacitor banks in transmission systems and where are they typically placed?

What is the primary purpose of capacitor banks in transmission systems and where are they typically placed?

• A. Capacitor banks store energy for inertia; placed at remote locations.
• B. Provide active power to the grid; placed at generation sites.
• C. Provide reactive power support to raise voltage and reduce losses; placed near load centers or along critical network points.
• D. Capacitor banks cool the transformers; placed in substations.

Answer: (C)

Capacitor banks provide reactive power support to the transmission system. Reactive power helps maintain voltage levels along lines and at buses, which keeps the grid voltage within limits and allows more real power to be transmitted with lower current. By supplying reactive power, they raise voltage and reduce I²R losses, improving overall efficiency and voltage stability. They do not supply active power or energy storage for inertia, and they don’t cool transformers. Placement is driven by where voltage tends to sag or where reactive demand is strongest—typically near load centers or at critical points along the network, such as substations or long feeders. This targeted placement maximizes voltage support where it’s most needed and reduces losses along the path from generation to load.

Capacitor banks provide reactive power support to the transmission system. Reactive power helps maintain voltage levels along lines and at buses, which keeps the grid voltage within limits and allows more real power to be transmitted with lower current. By supplying reactive power, they raise voltage and reduce I²R losses, improving overall efficiency and voltage stability. They do not supply active power or energy storage for inertia, and they don’t cool transformers.

Placement is driven by where voltage tends to sag or where reactive demand is strongest—typically near load centers or at critical points along the network, such as substations or long feeders. This targeted placement maximizes voltage support where it’s most needed and reduces losses along the path from generation to load.