How to create a model for single line to ground fault for double circuit transmission system??

Hi i have a model for double circuit transmission system. But i am not able to dynamically set the fault distance on one of its line . More over i am implementing a fault location algorithm and all the values needed are scalars and from simulation i get only vectors. How to find the exact voltage and currents at the fault? currently i am saving the data to workspace so that it would be easier to implement filters in matlab rather than simulink.

i would appretiate any help with this regard. any links to any reading material on the net which specifically address this issue would also be helpful.

With regards, Mani

[Mani]

also how to calculate mutual impedance between the two transmission lines?