Short Circuit Calculation Method of Power System with Renewable Energy Sources and Experimental Verification

Abstract

In the short-circuit current calculation of power grid, the renewable energy sources (RES) cannot use the equivalent method similar to the traditional synchronous generator because of the access mode and low voltage ride through control strategy. Therefore, it is difficult to solve the short circuit current directly by the traditional fault analysis method. According to the control strategy and fault characteristics of different types of RES, the equivalent calculation model of RES is obtained, especially the equivalent calculation model of doubly fed power sources when the negative sequence short-circuit current is not zero. On this basis, the node voltages equation and the iterative calculation method of the short-circuit current for the power grid with different types of RES are given. Then, an experimental platform with RES is established. The correctness of the equivalent calculation model and the iterative calculation method of short-circuit current are verified by short-circuit experiment.