| The propagation characteristics of lightning surges in compressed SF(,6) gas insulated power substation was studied using an electromagnetic transients program. Numerical models were developed to represent the behaviour of different system components especially under lightning over-voltage conditions.;The characteristics of lightning surge propagation in overhead multi-phase untransposed transmission lines was analysed first. Modal analysis, together with special rotation techniques to fit time domain solutions were then used to simulate the wave propagation in multi-phase untransposed line in an electromagnetic transients program. Non-linear voltage-dependent corona attenuation and distortion phenomena were also investigated. Available field test results could be duplicated to within 5%.;The characteristics of lightning surge propagation in multi-phase single-core SF(,6) cables was studied next. A program was developed to obtain the cable parameters for typical cable configurations. The amount of core current returning through its own sheath and through the earth were computed to illustrate the single phase cable representation for wave propagation in single core SF(,6) cables. |
