For problem-solving of relaying and automatic equipment of power supply system stability, it is necessary to define the set non-symmetrical modes at short circuits, incomplete inclusions, and complex types of network non-symmetry in one or several points. Calculations are in some virtue nodes of multiple straight sequence voltages determined from the previous normal mode. The non-symmetrical method is the joint solution of the equation for schemes of the direct, return and zero sequences connected in the uniform system by ratios between the currents and voltage in each non-symmetrical element determined by specific non-symmetry types. The proposed method of symmetrical components in direct, return, and zero sequences, widely used in short-circuit currents - for diagnostics of a digital substation’s electrical equipment.