In this Chapter, transmission lines are treated as distributed circuits, in order to explain how travelling-wave phenomena are propagated and detected. The basic principles of travelling-wave schemes, the formation of relaying signals, Bergeron's equation and discriminant functions using single-phase line models are also explained. These principles are then extended to three-phase lines by decomposing the line into three equivalent single-phase lines using the modal decomposition approach.

Inspec keywords: power transmission protection; power system relaying

Other keywords: digital protection; modal decomposition; transmission lines; relaying signals; power systems protection; Bergeron equation; distributed circuits; discriminant functions; travelling-wave based protection

Subjects: Power system protection