Shunt capacitor banks, also called filter banks, are widely used in transmission and distribution networks to produce reactive power support.
ABB's capacitor bank protection is used to protect against faults that are due to imposed external or internal conditions in the shunt capacitor banks. Internal faults are caused by failures of capacitor elements composing the capacitor units, and units composing the capacitor bank. Other faults inside the bank can be a flashover within the rack (short circuit over a single or multiple series groups of units of the same phase) and rack phase-to-phase and phase-to-earth faults.