Abstract:

Aiming at the problem that the traditional symmetric component method can't be applied in power system fault analysis and calculation because of the asymmetry of the three-phase load in the distribution network,a network  equivalent Transformation method is proposed,which makes the original three-phase load asymmetric network satisfy the conditions of  the symmetrical component method.This method mainly transforms the three-phase parameter asymmetry part of the power network equivalently into a three-phase parameter symmetric network structure with a certain fault.The three-phase parameters of the circuit outside the newly added fault port symmetrically satisfy the conditions of use of the symmetrical component method.This method takes advantage of the simple structure and quick calculation of the symmetrical component method.We build a simulation platform for several load asymmetry scenarios and compare it with the calculation results of this method to verify its accuracy and feasibility.

Key words: distribution network, asymmetric load, equivalent transformation, symmetrical components method