Theses and Dissertations Collection

As the grid continues to evolve into the future, shunt capacitor banks continue to be relevant to the power network. Shunt capacitor bank protection is critical to ensuring banks are removed from the grid during faults and ensuring the bank is not removed for conditions in which it is safe for it to operate. The balance between sensitivity and selectivity has always been a challenge for engineers tasked with protecting shunt capacitor banks or any other power apparatus. Fuseless bank designs are becoming increasingly popular for their many benefits; however, one tradeoff with this design is the lack of visible fault indication as is present on fused banks. The protective relays on these banks become the first line of protection and it is imperative they are able to correctly identify bank faults. This thesis will examine a fuseless shunt capacitor bank connected in a grounded wye configuration and applied to a 345 kV transmission network. Two methods to protect this type of bank are examined. One approach uses the commonly applied voltage differential capacitor bank protection method, and another less commonly used fairly new impedance measurement method. The two methods are analyzed and compared in a software model to prove that the impedance based method offers increased protection and selectivity for the capacitor bank.