Generalized Fault-Location Scheme for All-Parallel AT Electric Railway System

The existing fault location methods for all-parallel autotransformer railway systems (AARS) have limitations because they are generally designed for several given feeding conditions. In alternate feeding conditions, the existing fault location methods do not work well and may have large errors. To solve this problem, we have proposed a generalized fault location scheme for AARS in this paper. After analyzing the fault characteristics of AARS, we classified the feeding conditions of the faulted section of AARS into three types and introduced the corresponding fault location methods. In order to identify the faulted section and its feeding condition, we first formed a switch state matrix based on the adjacency matrix and mapped the fault current distribution into a current state matrix, then we unified the two matrices into a fault state matrix to reflect the fault state of the AARS. Finally, a generalized fault location scheme was proposed based on a fault state matrix. The proposed scheme effectively eliminates the negative influence of feeding conditions on the fault location, and it can identify the fault type and locate faults in different feeding conditions. Several simulation cases verified the effectiveness of the proposed scheme.