CRITICAL SWITCHING IMPULSE BREAKDOWN OF LONG BUNDLE-CONDUCTOR GAPS

The paper presents a generalized physical approach to account for the effect of bundle geometry on critical switching impulse strength of lo ng air gaps. The model covers phase-to-ground as well as phase-to-phas e insulation. It has been applied to conventional symmetrical bundles as well as to more complex open configurations. The effect of bundle c onductors was investigated for the following basic configurations: con ductor-plane, conductor-rod, conductor-tower leg, conductor-tower wind ow as well as phase-to-phase, within a wide range of clearances. The m odel is compared with previous analytical approaches as well as to ext ensive experimental results.