Field-Circuit Coupled Modelling of Superconducting Cable for Positive and Zero Sequence Impedance Analysis

Abstract

This paper presents a simulation analysis method for the sequence impedance of three-phase cold insulated superconducting cable based on the field-circuit coupling model. In this model, the induced electric field of screening layer is calculated by the magnetic field model, and the time domain current in the superconducting cable is calculated by the circuit model. Then, the positive sequence and zero sequence impedance of the superconducting cable circuit are calculated. The simulation results are as follows: for the positive sequence impedance, under the same structural parameters, the positive sequence impedance of the superconducting cable is half of the conventional cable; When the screening coefficient of the superconducting screen is 80% ~ 90%, the positive sequence reactance increases by 18% ~ 35%. For the zero sequence impedence, it is about 5 times of the positive sequence impedence, which is slightly greater than the handbook recommended value X <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> ≈ (3.5 – 4.6)X <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> . When the screening coefficient of the superconducting screen is 80% ~ 90%., the zero sequence impedence increases by 2.8 ~ 5 times.