Fundamentals of Adaptive Protection of Large Capacitor Banks - Accurate Methods for Canceling Inherent Bank Unbalances

Shunt capacitor banks (SCB) are installed to provide capacitive reactive compensation and power factor correction. This paper derives technically accurate operating equations for capacitor bank short circuit protection that are derived assuming both inherent capacitor bank and system unbalance. The presented relay protection methods allow compensating simultaneously for the bank inherent unbalance and system unbalance increasing both sensitivity and security of protection. The presented methods also facilitate auto-setting and self-tuning applications