A Methodology for Power Dispatch Based on Traction Station Clusters in the Flexible Traction Power Supply System

TL;DR

This work tackles power flow control and dispatch in flexible traction power supply systems (FTPSS) by introducing traction station clusters (TSCs) that perform independent local phase-angle control, eliminating the neutral zone (NZ) and reducing reliance on global coordination. It develops a system-equivalence model that converts FTPSS into a constant-topology representation, enabling a univariate optimization on the A-TS phase $\delta_A$ and the definition of feasible phase-angle domains (FPAD) for active and reactive power circulation (APC/RPC). A three-mode power-dispatch (PDM, CPM, MCM) with corresponding RPA calculations handles uncertain train loads while respecting RPC margins, and is validated with MATLAB experiments showing fast convergence, accurate FPADs, and precise power distribution with no undesired circulation. The approach promises real-time, low-communication control and improved integration of renewable energy and braking energy recovery in FTPSS, with potential applicability to field deployments and large-scale electrified rail networks.

Abstract

The flexible traction power supply system (FTPSS) eliminates the neutral zone but leads to increased complexity in power flow coordinated control and power mismatch. To address these challenges, the methodology for power dispatch (PD) based on traction station clusters (TSCs) in FTPSS is proposed, in which each TSC with a consistent structure performs independent local phase angle control. First, to simplify the PD problem of TSCs, the system is transformed into an equivalent model with constant topology, resulting in it can be solved by univariate numerical optimization with higher computational performance. Next, the calculation method of the feasible phase angle domain under strict and relaxed power circulation constraints are described, respectively, which ensures that power circulation can be either eliminated or precisely controlled. Finally, the PD method with three unique modes for uncertain train loads is introduced to enhance power flow flexibility: specified power distribution coefficients between traction substations (TSs), constant output power of TSs, and maximum consumption of renewable resources within TSs. In the experimental section, the performance of the TSC methodology for PD is verified through detailed train operation scenarios.

Figures (8)

• Figure 1: Proposed FTPSS. (a) the FTPSS scheme with TSCs based on phase angle control. (b) Flowchart of system operation.
• Figure 2: System equivalent mothod. (a) Equivalent model for a TR branch. (b) Resistance-inductance model of bilateral power supply by N-TS and A-TS. (c) Equivalent method with $N_{\text{TR}}$ TR branches.
• Figure 3: System equivalence method for ZSO.
• Figure 4: Flowchart for calculating FPAD of TSC, $\Xi_{\delta}^{\text{TSC}}$.
• Figure 5: Verification of FPAD calculation method. (a) The curves of N-TS and A-TS power. (b) The traffic operation schedule. (c) The zero-point trajectories of N-TS and A-TS power curves.