Protective Relaying, 4th Edition

Chapter 10

Bus Protection

10.1 Introduction: Typical Bus Arrangements

Buses exist throughout the power system and, particularly, wherever two or more circuits are interconnected. The number of circuits that are connected to a bus varies widely. Bus faults can result in severe system disturbances, as high fault current levels are typically available at bus locations and because all circuits supplying fault current must be opened to isolate the problem. Thus, when there are more than six to eight circuits involved, buses are often split by a circuit breaker (bus tie), or a bus arrangement is used that minimizes the number of circuits, which must be opened for a bus fault. There are many bus arrangements in service dictated by the foregoing and ...