What is the reason for using reactor in capacitor bank?

0
     Capacitor banks are used in power systems to improve the power factor and reduce line losses. When a capacitor bank is switched on from its discharged condition, it can offer a sudden short circuit to the power supply, as well as the other capacitors in the bank that come in parallel at the instant of switching. This can lead to high inrush current, which can damage the capacitor as well as other components in the switchgear.

     To prevent damage from high inrush current, a reactor is connected in series with each capacitor in the bank. The reactor opposes any sudden change in current and limits the inrush current when the capacitor is switched on. The reactor also helps to limit the harmonic distortion caused by the switching of the capacitor bank.

     The value of the reactor is typically 5-7% of the capacitor KVAR rating. This ensures that the reactor is effective in limiting the inrush current without excessively limiting the current flow to the capacitor bank during normal operation. The reactor also helps to balance the current flow between the capacitors in the bank by limiting the current flow to the capacitor with the lowest impedance.

    However, the insertion of the reactor also raises the voltage across the capacitor, which can lead to increased voltage stress and a need for a higher voltage rating of the capacitor. The capacitor voltage rating needs to be increased from the usual 440 V to 550 V to ensure that the capacitor can withstand the increased voltage stress.

Electrical Interesting Questions | All Posts



Tags:
Post a Comment (0)
Previous Post Next Post