Cable-in-Conduit Conductor (CICC) prepared using REBCO cables is promising in high field applications such as fusion magnets, as REBCO coated conductor has high critical magnetic field and high current-carrying capacity. Since the critical current of REBCO tape is strain sensitive, the current-carrying performance of CICC sub-cables might decrease during the bending process into the solenoid magnet. It is necessary to study the bending performance of the CICC sub-cable and obtain its ultimate bending radius, to ensure the function and safety of the magnet. Mechanical simulation is a commonly used method for studying the strain of REBCO tapes during the bending process of CICC sub-cable and predicting critical current. In this paper, a bending simulation model for CICC sub-cable is established. Numerical result shows that the critical current obviously degrades due to compression between the cables, which is also verified with the experiments. A six-around-one CICC sub-cable based on REBCO spiral cable was fabricated, with a stainless-steel tube core. The sub-cable was sequentially bent to different diameters, with a set of variable-radius molds. Then the critical current was measured in the 77 K liquid nitrogen environment under self-field conditions. When the bending diameter is 80 cm, the critical current only decays by 3%. The research provides a practical reference for the bending issue of REBCO CICC magnets.

Hydrogen fuel cell power systems have achieved significant progress in reactant feed control, temperature and humidity control, energy efficiency, and output performance stability. However, practical deployment is still constrained by strong nonlinearity and multi-physics coupling inside the stack, actuator dynamics and delays, and stringent safety constraints. This paper systematically reviews research progress in control and energy management of fuel cell power systems for transportation applications. It identifies key constraints and coupling mechanisms, summarizes typical control strategies for hydrogen supply, air supply, and water-heat management while evaluating their engineering applicability. The review also covers mainstream hybrid topologies and energy management methods, emphasizing the trend toward unified optimization targeting health status and multiobjective trade-offs. Finally, holistic optimization should move toward AI-enabled frameworks that combine multi-physics coupled simulation with perception-control synergy, and be validated under commercial boundary conditions such as sub-zero start-up, shutdown purging, thermal limits, and high-altitude operation.

Superconducting electrodynamic suspension (EDS) maglev technology has strong potential for ultra-high-speed transportation, with advantages such as self-stability and a large suspension gap. The magneto-electric force relationship between the onboard superconducting magnet and figure-eight null-flux coils is the key to improving system performance. This article shows a novel study on the impact of the shape of null-flux coils on the superconducting EDS maglev system, which has not been systematically studied before. A 3D model of the suspension system of EDS maglev was built using the finite element method (FEM) to study the impact of the null-flux coils' shape. The electromagnetic forces generated by the system were calculated and compared with those in the literature to validate the model. The results showed that rectangular and circular coils displayed different influences on the components of the electromagnetic force. New results and analysis from the article show that the null-flux coil shape is a promising option for system performance optimization and can provide a theoretical basis for future improvements to the high-speed EDS maglev system.

This article proposes a novel hydrogen-electricity hybrid-energy transmission system for an actual urban rail transit line at Jiading District, Shanghai, with multi-energy analysis on the clean energy, transportation applications, and surrounding infrastructures. The system utilizes photovoltaic-generated green electricity for water electrolysis and LH2 production at Jiading Hydrogen Port. The produced LH2 serves as a cryogenic coolant for MgB2-based superconducting cables, and as a clean fuel for transportation applications. The proposed system is also well suited for future development of more hydrogen transportation tools (e.g., hydrogen-powered trains) and clean energy (e.g., extra local wind power) in the region. The proposed system reduces transmission losses by 89% (considering cryogenic energy consumption), compared to conventional cables. Net present value analysis further reveals its economic viability under varying discount rates and transport distances. By integrating electrical energy, cold energy, and chemical energy, this novel hydrogen-electricity hybrid-energy transmission technology can offer efficient energy supply for urban rail transit and surrounding infrastructures.

Using cold energy can reduce electricity consumption of the hydrogen liquefaction process, and liquefied natural gas (LNG) receiving stations can provide abundant and low-cost cold energy. From this perspective, an innovative hydrogen liquefaction system using LNG cold energy was proposed. The novelty lay in using LNG cold energy to pre-cool both hydrogen and helium, which was different from the conventional system that only utilizes LNG cold energy for hydrogen pre-cooling. This design enabled helium compression at cryogenic temperatures, simplifying the refrigeration system and effectively reducing electricity consumption. Meanwhile, energy, exergy, and economic analysis were performed for the proposed system. The results showed that the specific energy consumption, coefficient of performance, and exergy efficiency were 3.65 kWh/kg, 0.333, and 39.51 %. The LNG receiving station in Yantai, China, and the hydrogen production data were used to perform a case study. When the price of liquid hydrogen was 5.2, 5.3, and 5.4 $/kg, the dynamic payback periods of the system were 9.4 years, 4.2 years, and 2.8 years. Overall, the proposed new system could offer technical advantages of reducing energy consumption and simplifying hydrogen liquefaction process, as well as favorable economic advantages over conventional systems.

The integration of superconducting magnetic energy storage (SMES) technology with battery systems to form hybrid energy storage systems has emerged as an optimal solution for multi-time-scale energy regulation. This article developed a novel droop control strategy for the hybrid SMES system, and the energy interaction behaviors were studied during dynamic compensation. An experimental platform was developed to verify different time-scale energy compensation and transient voltage/current peaks suppression under complex conditions, whose performance was better than conventional hybrid energy storage devices. The proposed hybrid SMES system addresses the limitations of single-mode SMES in short-period compensation and mitigates the ripple and peak current issues associated with single-mode battery systems. Additionally, both experimental and modeling studies on the dynamic loss of SMES magnets under complex conditions were conducted, representing a systematic experimental investigation that was absent in previous research. Overall, the experimental and modeling results of dynamic compensation/loss of the hybrid SMES system can provide useful instructions for the design, fabrication, and operation of high-performance hybrid energy storage devices.

For the target of 2060 carbon neutrality, extensively increasing the utilisation of solar and wind renewables poses a challenge in surplus energy compensation and multi-site long-distance power transmission. In this article, we proposed a superconducting hybrid-energy transmission and storage system, which can realise surplus energy absorption through large-scale liquid hydrogen production/storage consumption and large-capacity multi-energy transmission. This article uses the real data of renewable power generation and the real data of electricity generation/demand in provinces in China to perform realistic technical and economic analysis. The results show the proposed hybrid-energy system can potentially expand the existing renewable power generation capacity by 2 times and liquid hydrogen production capacity by 4.8 times. Overall, the proposed system can expand the utilisation of renewable energy through the large capacity energy transmission and energy conversion/storage, and solve the electricity generation-consumption imbalance in various regions and realise potential 100% renewable energy demand-fulfilment. A proposed superconducting electricity– hydrogen transmission system could expand renewable utilisation and liquid hydrogen production according to modelling with real provincial Chinese data assessing surplus absorption and regional balancing.

Superconducting magnetic energy storage (SMES) is a highly efficient energy storage technology with important applications in energy systems. In this article, SMES was proposed for the use in the railway systems, in order to solve the voltage/power fluctuations caused by intermittent renewable energy and acceleration/braking of trains. This article presents detailed methods for the structural optimization, fabrication, and experimental validation of the SMES magnet for possible railway applications. By optimizing the locations of six double-pancake coils, the energy storage capacity effectively increased. The SMES magnet was successfully fabricated and evaluated through critical current and magnetic field measurements, where the experiment matched the modeling. Given to the complexity and high cost of full-size experiment, it is reasonable to start with the modeling of a SMES-based railway system. By importing the experiment data of the SMES magnet into a model of traction power system of urban rail transit with SMES, the capability of fast energy compensation/recovery was verified. In this article, the design, optimization, fabrication and analysis of the SMES magnet provide useful guidance for the development of SMES technology to be used in railway systems.

Droplet impingement on hot surfaces is a critical heat transfer process in advanced thermal management systems. When wall temperatures exceed critical thresholds, a vapor film can form upon droplet contact, drastically reducing heat transfer efficiency. This study proposes a novel scheme featuring three innovative wall configurations (smooth ceramic baseplate, bare micropillar arrays, and micropillar arrays integrated with an electrospun SiO2 nanofiber membrane) to elucidate the individual and combined roles of micropillars and hydrophilic fibrous layers in mitigating vapor-film formation and enhancing droplet heat transfer on high-temperature surfaces. An integrated experimental platform was developed to precisely regulate impact parameters while monitoring transient energy exchange through synchronized high-speed visualization and thermocouple arrays. The surfaces were fabricated using P mu SL-printed ceramic micropillars and electrospun quartz nanofiber membranes, with comprehensive uncertainty quantification. Experimental results show that bare micropillar arrays suppress droplet spreading while intensifying heat flux, yielding a 71% increase in peak thermal transport (36,400 W/m 2 ) for cylindrical arrays at 500 degrees C. Integration of fibrous membranes significantly enhances the effective interfacial area for heat transfer by 43%, while extending the phase-change duration sixfold. Crucially, the composite configurations exhibit exceptional thermal-energy conversion synergy, where micropillar arrays inhibit Leidenfrost phenomenon through enhanced liquid-solid contact while fibrous membranes optimize vapor management pathways. The novel scheme provides critical insights into interfacial heat transfer mechanisms and establishes practical design principles for next-generation thermal management systems through composite configuration engineering, opening new avenues for efficient thermal energy utilization in high-temperature applications.

600 km/h high-speed maglev requires levitation electromagnets to maintain safe operation. These components face a critical thermal challenge: higher operating speeds demand stronger electromagnetic forces, which generate excessive heat and accelerate insulation aging. This thermal challenge directly threatens maglev reliability. Aiming to achieve fast and accurate temperature estimation for electromagnets, this article presents a novel fast-accurate electrical-thermal model by the Lumped Parameter Thermal Network (LPTN) method. The method utilized physics-based parameters to establish geometric nodes and multilayer foil thermal conductivity. An experimental electromagnetic-thermal test platform was established. To validate the model, experimental and analytical studies were performed on a single levitation electromagnet under static conditions, utilizing the 30 A current load derived from the 600 km/h design requirement. The LPTN model showed good accuracy in upper epoxy surface (7.43% error and 11.10% error compared to FEA and experiment). Furthermore, the LPTN has obvious advantage in calculation speed compared to FEA, with a reduction of 95.70% for calculation time. Both experimental and simulation results show that the proposed LPTN model provides a fast and precise solution for real-time temperature monitoring of high-speed maglev electromagnets.

This study proposed a novel low-carbon hydrogen-electricity energy supply system for the China-Thailand highspeed railway by integrating hydrogen-electricity superconducting pipelines with surrounding wind and solar resources. Wind and solar resources within 100 km along the railway corridor were systematically assessed. A 25 kV/3 kA hydrogen-electricity superconducting energy pipeline was designed to be used in the high-speed railway networks. Modeling showed the pipeline could deliver up to 10,713 kg of LH2 per day. Kunming was selected for technical, economic, and environmental evaluation. At an 8% discount rate, the system applied to Kunming achieved a discounted payback period of 15 years and reduced annual carbon emissions by 78.32%. However, under the current utilization of renewable energy around Bangkok, the proposed system didn't show proper environmental benefits, which implied the proposed system needed further development of surrounding renewable resources. By jointly delivering renewable electricity and renewable-based hydrogen through superconducting pipelines, the system efficiently supplied railway energy demand and enabled large-scale hydrogen production and transport. Overall, the proposed approach provided a viable pathway to expand renewable energy utilization and support low-carbon transport across Southeast Asia.

Electric vehicles (EVs) have been developing rapidly in recent years. However, the charging speed of existing EVs has encountered a bottleneck, which has become a major constraint on their further development. Superconducting cables offer significant advantages, including high current-carrying capacity and low losses, demonstrating great potential for enhancing EV charging performance. In this paper, we design a superconducting charging plug - a specialized connector for EVs - based on a flexible superconducting cable, aiming to achieve faster charging. Through a combination of mechanical simulation and experimental validation on custom-fabricated single- and doublelayer cable samples, the critical twisting angle was evaluated. The results show that the proposed cable design exhibits superior torsional performance, with a critical twisting angle per meter that is 49.68% higher than that of conventional copper-core CORC cables. This work provides key insights for the structural optimization of high-performance superconducting charging systems.

With the development of Electrodynamic Suspension (EDS) maglevs for future railway transportation, the coupling relationship between superconducting magnets (SCMs) and track coils has drawn increasing attention. This article presents a novel study on the impact of the SCMs tilting angle θ with detailed electromagnetic-force analysis for EDS maglevs, addressing the insufficient consideration of SCMs tilting effects in previous studies. Using finite element method (FEM) simulations with the rotating mechanical magnetic (rmm) module, combined with the A-V mixed formulation and linear extrusion operator function, the electromagnetic characteristics of the suspension coils were analyzed as SCMs passed at 600 km/h with tilting angles θ ranging from 0° to 11°. Results indicate that θ altered the electromagnetic characteristics, broadened the magnetic flux density distribution. The induced current density exhibited a different response, with a notable increase in the z-axis direction and a phase advance of 1/4 cycle. The variation in electromagnetic force was similar to that of current density. These phenomena were mainly due to the closed-loop feedback mechanism of the suspension coils, which adaptively compensated for asymmetric magnetic coupling distortion. Overall, a novel study was conducted on the impact of the SCMs tilting angle θ for EDS high-speed maglevs, providing a theoretical basis for understanding complex coupling behaviors, and offering strategies for improving the structure and suspension system of future EDS maglevs.

High-temperature superconducting cables possess the advantages of relatively low weight per unit length, high current carrying capacity, and strong resistance to complex electromagnetic environments, which can meet the needs of the further development of exploration technologies. Superconducting flexible core cables have a small bendable radius, and the manufacturing processes of materials and supporting components are relatively simpler. In response to the requirements of mechanical strength and lightweight for aviation geological exploration systems, this paper proposes a topological structure of an electromagnetic emission coil based on lightweight high-temperature superconducting bundled cables. The critical current changes and AC losses when applied in electromagnetic emission conditions are calculated and studied.

Urban rail transit networks are huge energy consumers. This paper proposes a novel hydrogen-electricity hybrid-energy system for urban rail transit, with liquid hydrogen and the superconducting magnetic energy storage (SMES) and battery energy storage (BES) hybrid energy storage system (HESS). The study shows that the proposed SMES-BES HESS technology can properly provide energy compensation and conversion for the frequent acceleration/braking of metros. The overall hydrogen-electricity hybrid-energy system for urban rail transit can utilize the surplus renewable energy and energy waste caused by regenerative braking of metros, and produce clean hydrogen for nearby infrastructures. The economic analysis shows that the payback period of the SMES-BES HESS is around 9 years and the payback period of the overall hydrogen-electricity hybrid-energy system for urban rail transit is 14.6 years (both with discount rates). In summary, the novel hydrogen-electricity hybrid-energy system with SMES-BES HESS technology can greatly enhance the energy utilization and coordination of urban rail transit system, and promote the deep integration of railway systems and clean energies.

Renewable energy such as photovoltaic and wind power was developing rapidly. Meanwhile coal-generated and gas-generated electricity generation were declining and might even be phased out. However, renewable electricity has long-term fluctuations across seasons, and it is difficult to accurately match the electricity load. A novel large-scale long-term hydrogen energy storage/release system was proposed and constructed, which enabled the balance of renewable energies through cross-seasonal hydrogen storage and improved energy efficiency via waste heat and cold recovery. According to the government data and models, Hainan Tibetan Autonomous Prefecture in Qinghai Province was taken as a typical case. Furthermore, the 4E (energy, exergy, economic, and environmental) analysis was conducted on the case to evaluate its performance. The results showed that during energy storage, the energy efficiency and exergy efficiency of the system were 55.50 % and 59.65 %. During energy release, the energy efficiency and exergy efficiency were 70.07 % and 79.34 %. The electric round-trip efficiency was 40.40 %. Additionally, the system could supply 44.24 Mt. of hot water and 0.63 Mt. of cold water annually, with the round-trip efficiency reaching 48.76 % when thermal output was considered. In terms of economic indicators, the dynamic payback period in this case was 9.07 years, and the internal rate of return was 11.23 %. In addition, the proposed system reduced coal (7.95 x 105 tons) and natural gas (2.71 x 104 m3) consumption annually, which means 2466.13 kt in carbon emissions could be reduced. Overall, the technical, economic and environmental advantages of the novel system could provide solutions for the balance of renewable energies and global decarbonization.

As the second most widely used metal, aluminium presents an urgent need for environmental friendliness. It is essential to explore pathways of energy saving and emissions reduction for the sustainable growth of aluminium industry. This article proposes novel methods to quantify and estimate the pollutants (PM, SO2, NOx) and CO2 emissions from the aluminium industry in China. Both process engineering and fuel combustion emissions are incorporated into one integrated model for conducting a more comprehensive assessment of the impact of pollutants and emissions. The pollutant emissions from the indirect power consumption process are further estimated based on different aluminium production processes and pollutant sources. Based on this, five typical scenarios are designed to assess how changes in fossil power proportion, emission factors, and energy intensity influence emissions in China's aluminium industry from 2022 to 2060. Results indicated the introduction of hydropower and solar + wind power contributes most prominently to emission reductions, and the comprehensive scenario has the best performance, reducing the CO2 emission in indirect power consumption from 389.1 Mt in 2022 to 1.51 Mt in 2060, when the carbon neutrality goal could almost achieve. Overall, the novel methods for quantifying/estimating pollutants and CO2 emissions from the aluminium production can provide useful pathways for the energy saving and emissions reduction of aluminium industry.

Hydrogen storage enables long-duration energy storage, while superconducting magnetic energy storage (SMES) can rapidly smooth power fluctuations. A hybrid energy storage system (HESS) combining both is highly suitable for enhancing the reliability and stability of the high-speed railway (HSR) traction power supply system (TPSS). A novel energy management strategy of HESS for HSR TPSS was proposed. Firstly, the representative daily power curves were extracted by a clustering method, and an improved moving average filter and amplitude limiting filter (IMAF-ALF) algorithm was employed to limit the change rate of net power. Then, the remaining fluctuating power was adaptively decomposed by adaptive variational mode decomposition (VMD), which assigned the high-frequency components to SMES and the low-frequency components to hydrogen storage. In addition, a mixed integer linear programming model was developed to optimize capacity allocation, minimizing annual system cost while satisfying power and energy constraints. Results showed that the proposed energy management strategy can effectively mitigate the intermittency and volatility introduced by grid-connected renewable energy generation, suppress traction load surges, reduce system losses and investment costs.

This article investigates a wind–solar–biogas complementary integrated energy system (IES) for achieving combined cooling, heating, and power (CCHP) supply in agricultural parks. The system consists of wind power, photovoltaic power, biogas-based combined heat and power (CHP), waste heat boilers, electric heating/cooling units, absorption chillers, and energy storage devices. Using Changma Village, Baiwu Town, Yanyuan County, Sichuan Province as a case study, a multi-objective optimization model was established with the objectives of minimizing operating costs and carbon emissions. An improved multi-objective grey wolf optimizer (MOGWO) was applied to solve the model. The results show that the proposed method yielded a well-distributed Pareto front. In the optimal compromise solution, the total operating cost decreased from CNY 6461.77 to CNY 2070.51, a reduction of 67.96%, and the carbon emissions decreased from 13,740.72 kg to 2370.45 kg, a reduction of 82.75%. The proposed wind–solar–biogas complementary IES can enhance both the overall economic performance and low-carbon sustainability of the agricultural park energy systems.

Data centers generate substantial waste heat, while residential buildings have daily cooling and heating demands, resulting in significant energy consumption and carbon emissions on both sides. To promote the coordinated development of data centers and nearby buildings towards green and low-carbon goals, this paper proposes a novel waste heat recovery system for space cooling/heating and domestic hot water supply. To balance the overall energy efficiency and economic benefit, an optimal capacity configuration scheme based on the internal rate of return and dynamic payback period is further developed. Applied at a data center case in Chengdu, China, the system supplies energy to nearby buildings with a maximum cooling load of 5 MW and a heating load of 10 MW. The optimization identifies the most cost-effective configuration as a 3.5 MW water source heat pump and a 1.75 MW adsorption chiller. This setup achieves a dynamic payback period of 5.17 years and is expected to generate a total revenue of 2.58M$. Compared to a conventional district heating system, the proposed system shortens the payback period by 36 %, increases the revenue by 2.6 times, and reduces carbon emissions by 10 % for data centers and 84 % for residential buildings, cutting over 2800 tons of COQ annually. The proposed system offers a win-win solution both in terms of reducing the power usage effectiveness of data centers and decreasing carbon emissions in buildings. Finally, a generic design and evaluation framework for the technological, economic, and environmental analysis is explored to support broader applications of the proposed waste heat recovery system.