Tennessee Valley Authority´s 500-kY System - System Plans and Considerations

Insulation requirements for the Tennessee Valley Authority´s new 500-kV transmission system were found to be dictated by switching surge transient voltages rather than by lightning surges. Plans and considerations studied by the Tennessee Valley Authority in relation to the employment of 500-kV transmission are presented as comparative data which might be helpful to others interested in EHV installations. Descriptions are given of voltage levels and bundle conductors selected, subconductor arrangements, application of shunt compensation, reactive power supply, lightning performance, system stability, system grounding, insulation requirements, 500-kV bus arrangements and relaying, and transformer capabilities meeting the needs of 500-kV transmission in the TVA service area.