Open Access

ARTICLE

Optimal Scheduling of a Dual-Side Grid-Forming Through-Type Flexible Traction Power Supply System Integrated with Photovoltaics and a Hybrid Energy Storage System

Yi Wang, Haixin Wang^*, Haoyan Gao, Sida Wang, Yongqing Cai, Minghang Cao, Mingchao Xia, Junyou Yang, Shengyang Lu
School of Electrical Engineering, Shenyang University of Technology, Shenyang, China
* Corresponding Author: Haixin Wang. Email:
(This article belongs to the Special Issue: Advanced Analytics on Energy Systems - 2nd Edition)

Energy Engineering https://doi.org/10.32604/ee.2026.088022

Received 26 June 2026; Accepted 31 August 2026; Published online 07 September 2026

Abstract

Against the background of the new power system, a dual-side grid-forming through-type flexible traction power supply system (DGF-TPSS) incorporating photovoltaic (PV) generation and a hybrid energy storage system (HESS) is proposed. The system is designed to address the challenges of large traction load fluctuations, low utilization of regenerative braking energy, and the difficulty of simultaneously achieving economic operation and operational flexibility after renewable energy integration in through-type power supply systems. Based on a dual-side grid-forming multi-port converter, a scheduling-oriented operation model is developed for strong-grid and weak-grid conditions, characterizing the power flow relationships among the utility grid, two adjacent traction substations, PV, and HESS while considering equivalent traction-line and converter losses. Furthermore, a mixed-integer linear programming (MILP) optimal scheduling model considering time-of-use (TOU) electricity pricing, demand charges, feedback pricing schemes, port capacity limits, and HESS operating constraints is developed. Case study results show that, with only PV integrated, the maximum 15-min average demand is reduced from 8.21 MW to 7.16 MW. After further introducing the HESS, the maximum demand is reduced to 2.84 MW. Relative to Case 1 under partial feedback pricing, the total daily operating cost decreases from 57,291.38 CNY to 22,160.05 CNY. The PV utilization rate and local utilization rate of regenerative braking energy increase to 91.13% and 96.65%, respectively. In addition, under the traction-side islanded and weak-grid power limited scenarios, the system maintains internal power balance and continuous traction load supply while reducing the power demand imposed on the weak grid, thereby demonstrating the feasibility of the scheduled operating points under constrained grid-support conditions. These results demonstrate the economic and operational effectiveness of the proposed scheduling method.

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Keywords

Dual-side grid-forming; flexible traction power supply system; multi-port converter; hybrid energy storage system; optimal scheduling

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