Energy Efficiency Analysis and Energy Management of a Superconducting LVDC Network

A novel superconducting low-voltage direct-current (LVDC) power transmission and distribution network consisting of multiple superconducting dc cables and a superconducting magnetic energy storage (SMES) based hybrid energy storage system (HESS) is presented. The superconducting dc cables are favored for both high-efficiency power transmission under normal conditions and self-triggering fault-current-limiting operation under fault conditions. The SMES-based HESS is integrated, with the merits of fast response speed and high-power density from the SMES, and high-energy density and high-economic efficiency from conventional battery energy storage (BES), and thus, is much more effective a sole SMES or BES device for smoothing the line voltage fluctuations caused by some sudden load variations or short-circuit faults. The simulation results obtained from energy efficiency analyses and energy management simulations show that the proposed superconducting LVDC network has significant advantages in high-efficiency, high-quality power transmission and distribution compared to conventional ac networks.