Inductive power transfer (IPT) systems are transforming railway infrastructure by enabling efficient, wireless energy transmission for electric locomotives equipped with Li-ion batteries. This technology eliminates the need for overhead power lines and third rails, offering financial and operational advantages over conventional electric propulsion systems. Despite its potential, IPT deployment in rail applications faces significant challenges, including the fragility of materials (i.e., ferrite and Litz wires), thermal management during high-power transfers, and electromagnetic interference (EMI) on the transmitter side. This study discusses several factors affecting IPT efficiency and introduces magnetic concrete as a durable and cost-effective material solution for IPT systems. Magnetic concrete combines soft ferrite powder with water and coarse aggregates to enhance magnetic functionality while maintaining structural strength comparable to conventional concrete. Its durability and optimized magnetic properties promote consistent power transfer efficiency, making it a viable alternative to traditional ferrite cores. A comparative study has been performed on non-magnetic and magnetic concrete (with 33% ferrite powder) using both permeability tests and finite element analysis (FEA). The FEA includes both thermal and electromagnetic simulations using Ansys Maxwell (v.16), revealing that magnetic concrete can improve temperature management and EMI mitigation, and the findings underscore its potential to revolutionize IPT technology by overcoming the limitations of traditional materials and enhancing durability, cost-efficiency, and power transfer efficiency. By addressing the challenges of fragility, thermal management, and shielding of the unique coil topology design presented, this study lays the groundwork for improving IPT infrastructure in sustainable and efficient rail transport systems.

Lithium-ion battery (LIB) wireless charging using inductive power transfer (IPT) represents a transformative pathway for transportation electrification. While applications in railway systems remain limited, early studies highlight significant promises for implementation. This paper presents a hybrid energy-supply framework integrating LIB, inductive battery charging (BC) charging, and battery swapping (BS) to support a 20 km heritage trolley excursion between Belmont and Gastonia, NC. A kinematic simulation was developed to estimate traction energy demand, yielding 56 kWh per trip, or 112 kWh for two daily round trips. Finite element analysis (FEA) was conducted to design an LCL-s compensated 3 kW IPT system. Two transmitter configurations were evaluated: W–I ferrite cores (peak coupling ~0.22) and magnetic concrete slabs (~0.20). Although ferrite offers higher efficiency, magnetic concrete demonstrates superior durability and integration potential. Simulation results indicate that wireless charging alone, whether static or dynamic, is insufficient; similarly, a single daily BS strategy provides only 96 kWh. Seven BC-BS hybridization scenarios were evaluated, showing that mid-day swaps combined with either static or dynamic IPT produce a 12–16 kWh surplus. The most practical approach is a one-pack swap supplemented by uniformly distributed static pads, providing energy neutrality. This hybrid pathway ensures operational sufficiency, structural resilience, and compatibility with heritage rail preservation.

Solid-state circuit breakers (SSCBs) have gained significant attention in the field of power system protection due to their fast fault-interruption capability and arcless operation. However, conventional SSCBs suffer from a relatively low DC voltage utilization ratio (VUR) resulting from the leakage current and I-V characteristics of the metal oxide varistors (MOVs), which in turn reduces overall efficiency and increases the cost of power semiconductors when operating at higher DC voltages. This article proposes a novel bidirectional DC SSCB that eliminates MOV leakage current under all operating conditions through a switch–diode–MOV branch, thereby increasing the DC VUR. The proposed topology also supports modular SSCB configurations for high DC voltage applications and fast fault isolation. The DC VUR and operating principles are first analyzed, followed by key design considerations—including DC-link snubber, switch snubber, MOV, and modular structure—supported by theoretical analysis. The effectiveness of the proposed SSCB is validated experimentally at DC voltages of 850 and 1700 V with a fault-interruption current of 150 A. Finally, a comparison with existing high VUR topologies demonstrates that the proposed topology achieves the highest DC VUR of 71% among those employing 1200 V rated switches. This advancement reduces device voltage rating requirements and cost, making 1200 V devices a practical and cost-effective solution for 850 and 1700 V DC systems.

Wireless power transfer (WPT) offers a promising solution for continuous and contactless energy delivery to battery-electric locomotives (BELs). It enables in-motion charging, which can significantly reduce the need for prolonged static charging sessions and allow for smaller onboard battery capacities. This paper presents a dynamic wireless power transfer (DWPT) system specifically designed for BEL applications, employing a parallel synchronized multiple LCL-S compensation topology operating at a switching frequency of 85 kHz. A method for calculating the dynamic coupling coefficient $k$ is proposed to model the time-varying magnetic coupling during motion. To validate the system, a prototype incorporating three transmitters (Txs), one receiver (Rx), and a W-I-shaped magnetic coupler is developed and tested. During static charging, the experimental results demonstrate a peak DC-DC efficiency of 94.73% at 3.1 kW input power, with over 92% efficiency sustained across a wide range of input voltages and output load resistances. During dynamic charging, the system maintains a stable efficiency with the maximum value of approximately 89%. These results also show agreement with theoretical predictions, validating the system's performance and robustness.

Lithium-ion battery (LIB)-powered locomotives have emerged as a promising alternative to conventional rail electrification by reducing dependence on overhead catenary systems, lowering infrastructure costs, and improving operational flexibility. However, train failures involving power loss or mechanical faults present significant challenges for battery-powered rail systems, particularly on single-track corridors where alternate route options are limited. Consequently, the implementation of a reliable limp-home strategy is more complex than in road electric vehicles (EVs), requiring consideration of battery availability, rescue logistics, and track accessibility. This study investigates limp-home operation and rescue planning for a battery-powered historic trolley operating on a 20 km heritage route in North Carolina. The trolley is powered by a dedicated LIB trailer and supported by battery-charging (BC) infrastructure based on inductive power transfer (IPT) technology. A comprehensive framework is developed that integrates time–space analysis, cellular automata (CA)-based failure-risk modeling, and battery-energy assessment to evaluate train-failure scenarios and recovery strategies. The results identify critical failure regions along the route and demonstrate the benefits of strategically deploying additional LIB rescue trailers and wireless power transfer (WPT) infrastructure. A revised rescue strategy incorporating two additional LIB trailers, together with static and dynamic WPT systems, substantially reduces recovery time and improves the likelihood of maintaining scheduled excursions. Emergency energy analysis further shows that WPT-assisted operation can significantly extend limp-home capability under low state-of-charge conditions. Based on the integrated analysis, a tiered limp-home decision framework is developed to support operator decision-making during train failures. The proposed methodology provides a practical approach for enhancing the resilience, recoverability, and operational reliability of battery-powered heritage rail systems and can serve as a foundation for future battery-electric rail applications.