Lightning surges in hybrid cable-overhead lines: Part II—voltage estimation for strikes to shield wire

This paper (Part II) continues the study from Part I by presenting formulas able to do a fast estimation of the voltage at an underground cable sheath for lightning surges striking an earth wire, with and without back-flashover. Similar to Part I, these formulas do not require an electromagnetic transients (EMT) software and can be implemented as scrip for a fast screening of potential issues, requiring solely the geometric data of the cable and the overhead line. The potential impact and limitations of the simplifications are evaluated.