Digital Solution of Short-Circuit Currents for Networks including Mutual Impedances

A method has been presented for the digital solution of a short-circuit tensor and its use for the calculation of currents in lines including those having mutuals. The short-circuit tensor can be easily modified for line additions, deletions, or line-open conditions, thus eliminating the necessity for lengthy calculations for each fault condition. Networks may be divided into parts and the short-circuit tensor for each section solved for exactly, without deriving any approximate equivalents. Short-circuit tensors can be derived for each of the positive-and zerosequence networks of a system and the same program used for either phase or ground current calculations. Only the desired fault and line current are punched out.