A new calculation method for open-phase fault based on superposition principle

According to open-phase fault condition occurred in power system, this paper proposes a new calculation method based on superposition principle. The open-phase fault network is equivalent to the superposition of a disconnection state before faulting and an additional short-circuited state, after calculating the two states respectively and superposition of the results acquired, calculation formula of electric quantity in open-phase fault network can be obtained. In this paper, two kinds of fault during the open-phase running are calculated: fault occurs on the faulty phase and on the sound phase. The formulation of the post-fault electrical quantities is obtained. Numerical examples and the simulation results from PSCAD demonstrate that the proposed method has good effectiveness and feasibility.