Estimation of Reactive Power and Harmonics by Simulating a 12-Pulse Converter Power Supply for Tokamak Superconducting Coils

Abstract

Fusion experiments utilizing the Tokamak concept, which involves toroidal magnetic confinement, necessitate several magnet coils arranged in a specific configuration. For extended operations, superconducting coils emerge as the most economical choice due to their near-zero resistance and inductance values ranging from 2 mH to 1200 mH. These coils are capable of generating high magnetic fields with precisely profiled high direct current (DC). When selecting a power supply for the superconducting magnet coils, various configurations are available, and the decision is influenced by factors such as the requirement for high current with relatively low voltage DC output, the need for high ramp voltage versus low hold voltage, and the efficiency of converter devices. In this paper, we model the power supply for one of these superconducting magnet coils using MATLAB® and simulate it with Simulink®. This setup comprises a 12-pulse AC-DC converter equipped with an extended delta D(+150)y0-y6 converter transformer, an H3 bridge (a Half Bridge configuration featuring three thyristors arranged in a bridge setup within a three-phase system), and an Inter-phasing Reactor.