Numerical Study on Transport AC Loss Characteristics of Toroidal Air-Core Superconducting Shunt Reactor

Shunt reactors are widely adopted in low-voltage-level stations to solve the reactive power reversal in urban power grid. Compared with traditional iron-core shunt reactor, toroidal air-core superconducting shunt reactor comprehensively exhibits the advantages of high compactness, low magnetic field leakage and low noise. However, relatively high transport AC loss may pose unexpected huge burden to cryogenic system, hindering the stability and feasibility of superconducting shunt reactor. In this paper, a partial-size model with appropriate geometrical simplifications is built to analyze the electromagnetic characteristics of toroidal superconducting shunt reactor with racetrack double-pancake (DP) coil as the least unit. Result shows the effect of toroidal structure on the amelioration of the uniformity of magnetic field distribution, leading to the suppression of the transport AC loss. This improvement will give practical engineering guidance to the future application of toroidal superconducting shunt reactor.