Some complex types of damage can occur in power lines, for example, a short circuit with a wire break. This mode can occur when a wire of any phase falls to the ground (Fig. 1).
Fig. 1. Single phase short circuit with phase failure
This complex damage can be considered as a simultaneous combination of two modes: short circuit and open circuit in the same phase. In phase coordinates, the location of damage can be represented as a cascade connection of two multipoles, one of which is a direct transmission matrix of the fault location, the other is a direct transmission matrix of the breakage model (Fig. 2).
Fig. 2. Equivalent circuit of a single-phase short circuit with phase failure
The equivalent damage direct transmission matrix will be determined by the formula
Af = A1 ∙ A2,