Fault locating of traction power system with series-wound compensators based on morphological gradient and parameter identification

The series-wound compensators are added in traction power system of some electric railway,which damages the corresponding relation between short-cireuit reactance and fault distance when fault occurs.The fault model and short-circuit characteristic of this type of traction power system are studied and several fault locating methods based on morphological gradient for the induced voltage changes are compared.A fault locating method based on second-order morphological gradient for the short-circuit at capacitor discharge moment is proposed.ATP simulation and Matlab analysis for different capacitor voltage angles and different transitional resistances of a traction power system with series-wound compensators show that,the proposed method can identify the short-circuit fault at capacitor discharge moment.Combined with the way of judging whether the fault is before or behind series-wound compensator by capacitor parameters and the calculated short-circuit reactance by Fourier transform,the fault is located using the relation table between reactance and distance.