Stability Analysis of Multinode Locomotive Integration Into a Traction Power Supply System Based on a Generalized Short-Circuit Ratio

The generalized short-circuit ratio (gSCR) is commonly used in stability analysis of three-phase grid-connected inverters. It provides advantages such as effective grid performance measurement, simple calculations, clear physical meaning, and few usage restrictions. However, in single-phase electric trains, converters contain second-order generalized integrator (SOGI) components. The impact of these components on gSCR modeling and stability has not been sufficiently addressed in previous works. This article proposes a gSCR model that integrates locomotives into a multinode traction network. It explores how SOGI causes the power simplification method to fail. Additionally, it investigates how SOGI leads to opposite effects of power on stability in single-phase and three-phase systems. This article defines the critical gSCR (CgSCR) and analyzes its variation in a multilocomotive integrated system (MLIS). By comparing the values of gSCR, the system stability is determined. Finally, the theoretical analysis is validated through a hardware-in-the-loop (HIL) platform. This indicates that the gSCR modeling method offers simplicity, fast calculations, clear physical meaning, and accurate assessments in the stability analysis of MLIS.