随着国家现代工业的飞速发展，电量需求量不断提升的同时，对输电线路的电能输送效率与质量也提出了更高的要求。我国电力分布天然具有发电中心与负荷中心极度不匹配的特点，传统的架空线适用于远距离、大容量电力传输；常规的地下交直流铜缆适用于城市输电场合。在如今用电负荷逐年增加的大趋势下，实现大规模、远距离、高效率、低损耗且清洁性的电力传输对于我国的能源应用具有极为重要的战略意义。将高温超导电缆技术与柔性直流输电技术结合，不仅可以减小系统的运行损耗，也能够使传输系统的结构更加紧凑，是未来实现低损耗、大容量电能传输的潜在方案之一。天然气作为我国优质高效的绿色能源，若将其液化（112K）后替代液氮作为高温超导直流电缆的冷却液，可以实现电能与液化天然气的一体化输送。该方案能够提高系统整体效率，降低成本。因此，结合电力与能源高效一体化传输的高温超导直流能源管道技术越来越被重视。本文针对110kV/1kA高温超导直流能源管道导体建立二维及三维电磁仿真模型，对超导体内部电流分布及导体螺距对导体内部电流分布的影响进行研究。结果表明，二维模型及三维直线结构模型中的导体电流分布总是趋于导体外侧及两端；螺旋结构模型通过改变导体所处磁场而对导体内部电流分布产生影响。通过仿真结果及对导体截面电流密度的方差计算，本文中建立的螺旋结构模型导体内部电流分布较直线结构模型在稳态及暂态情况下均更加均匀，认为螺旋结构对导体内部电流分布具有一定影响。本文针对国家重点研发计划中超导直流能源管道在导体正常工况下与失超故障情况下对LNG运行状态的影响问题初步建立110kV/1kA高温超导能源管道三维电-热-流耦合仿真模型。对LNG在管道正常工况下与故障（失超）情况下的流速、温度及压力的变化规律进行初步分析，对高温超导能源管道的可行性及安全性进行初步评估。结果表明，正常工况下，超导能源管道温升主要来源于外界漏热，能源管道外壁的温度逐渐升高且向LNG流体内部深入，单位长度上管道最高温升达到0.1K；故障情况下，超导能源管道温升主要来源于由于导体焦耳热，在0.1s内管道最高温升约13K，且主要分布于内层导体及铜支撑上，但是对LNG的影响不大，初步认为该能源管道具可行性与安全性。
With the rapid development of the modern industry, the demand for electricity continues to increase. Higher requirements are placed on the efficiency and quality of power transmission of transmission lines. Under the trend of increasing electricity demand year by year, building large-scale, long-distance, high-efficiency, low-loss and clean power transmission system is one of the most significance strategy for China's energy application. Combining high-temperature superconducting cable technology with flexible direct current transmission technology will reduce the operating loss of the system. Moreover, it makes the structure of the transmission system more compact. It is one of the potential solutions for low-loss, large-capacity power transmission in the future. As a high-quality and high-efficiency green energy source in China, natural gas can replace the liquid nitrogen as the coolant of high-temperature superconducting DC cable. This will achieve the integrated transmission of power and LNG, which improves transmission efficiency and reduce costs. Therefore, high-temperature superconducting DC energy pipeline technology combined with efficient transmission of power and energy has been paid more and more attention.In this paper, a two-dimensional and three-dimensional electromagnetic simulation model is established for the 110kV/1kA high temperature superconducting DC energy pipeline conductor, and the influence of the internal current distribution of the superconductor and the conductor pitch on the internal current distribution of the conductor is studied. The results show that, the conductor current distributes on the outside and ends of the conductor; the spiral structure model affects the current distribution inside the conductor by changing the magnetic field of the conductor. By calculating the variance of the current density of the conductor cross section, the internal current distribution of the spiral structure model conductor established in this paper is more uniform than the linear structure model under steady state and transient conditions.In this paper, a three-dimensional electro-thermal-flow coupling simulation model is designed for 110kV/1kA high-temperature superconducting energy pipeline. The results show that, under normal working conditions, the temperature rise of the superconducting energy pipeline mainly comes from the external heat leakage. The temperature of the outer wall of the energy pipeline gradually rises and penetrates into the inside of the LNG fluid. The maximum temperature rise per unit length of pipeline is 0.1K. The temperature rise of the superconducting energy pipeline is mainly due to the Joule heat of the conductor. The maximum temperature of the pipeline rises about 13K in 0.1s, and it is mainly distributed on the inner conductor and the copper support, but has little effect on the LNG.
