Symmetrical component method
Method of symmetrical components, Fortescue method, calculation of short circuit currents, positive, negative and zero sequences.
Symmetric components are very important parameters used in relay protection to implement protection of various equipment. They allow you to implement more sensitive and specific types of protection.
Physically symmetric components in electrical circuits do not exist. Symmetric components were introduced to significantly simplify the calculation of three-phase circuits due to the fact that the mathematically asymmetric system of three arbitrary vectors can always be replaced by two symmetric systems of vectors and one system of three co-directional vectors (Fig. 1).