Research on the impact of superconducting cables on the urban power grid capacity

With the rapid growth of the power load in the urban centre, the expansion of power capacity by constructing conventional cables is not always feasible due to the limited underground passageways. The superconducting cable, possessed with features of zero resistance, large current-carrying capacity and small size has become an excellent solution to this problem. According to the cable characteristics, the fault of superconducting cable generally develops slowly. Besides, the carrying capacity of superconducting cable can be increased with the decrease of temperature and can achieve short-term overload under lower temperature conditions. Therefore, the application of superconducting cable essentially improves the safety of power grid equipment. According to the power supply, one superconducting cable can replace four to six conventional cables with same cross section and voltage level, and multiple switch stations in the central urban area can be merged into one switch station, which not only reduces the space demand for the central urban area, but also improves the construction feasibility of power supply facilities, and increases the flexibility and reliability of the power grid operation mode.