Dear Biobele,

As a starting point in a such research, you have a serious look at the following relevant book from Prof. Math Bollen: Understanding Power Quality Problems: Voltage Sags and Interruptions.

In the attached papers, you can also have a look at the introductions (sort of state of the art) that hope could be helpful.

Regards,

Mohamed

Dear colleague,

I think there are not any features in calculation of non-symmetrical short-circuit current for the case of double power transmission line at short-circuit happened in one if the lines. The only difference I think will be that an appropriate equivalent networks for all the sequences will include a triangle with the short-circuit place as one of the tops and double transmission line’s ends as other ones. The sides of the triangle will be impedance of the safe line and the partial impedances of the failed line between the short-circuit place and line’s ends.

Regards