Decoupling phase domain method to calculate open conductor faults in the double circuit line on the same pole

A decoupling phase domain method is given for calculating open conductor faults of the double circuit line on the same pole. In the phase domain, the double circuit line is decoupled in terms of only remaining fault lines while the two terminal nodes of the double circuit line are selected as boundary nodes. The proposed algorithm is easy to understand and unified by using the simple circuit theory to treat the complicated open conductor faults of the double circuit line. It has many advantages such as: (1) the complex connections between sequence networks are avoided in fault calculations; (2) the open conductor faults can be modeled accurately; (3) the influence of the fault impedance in incomplete open conductor fault can be modeled simply. The numerical example shows that the method is effective.