A simplified fault currents analysis method considering transient of synchronous machine.

The transient fault currents for a synchronous machine fault were mathmatically analyzed by using the two-reaction theory, Clarke's components, etc. However, the methods were extremely complicated and the transient fault analysis of synchronous machine with a load was not carried out except for three-phase fault. This paper proposes a simplified fault currents analysis method considering transient of synchronous machine. The method is based on the symmetrical-components. The advantages of the method are that the transient analysis is able to be accomplished more easily than the conventional method when the fault point is a synchronous machine terminal or a transmission line. The accuracy of the method is confirmed by comparing the analysis results with the Electro-Magnetic Transient Program (EMTP) digital simulations.