Principle and Theoretical Performance of the Saturable Transformer Fluxpump with a Resistive Commutation Method.

Abstract

A rectifier fluxpump (superconducting rectifier) is one of power source units for a superconducting magnet. This apparatus converts an AC current having a small amplitude into a large DC current suitable for the superconducting magnet using a superconducting transformer and two superconducting switches. A typical conventional rectifier fluxpump with the superconducting transformer by using an air-core has such defects that the pumping flux is small and decreases as charging current for the superconducting magnet increases. We noted the fact that a magnetization curve of magnetic core of the superconducting transformer is related with pumping flux of the rectifier fluxpump and studied a new-type rectifier fluxpump with the superconducting transformer by using a saturable iron-core, namely, saturable transformer fluxpump.In this paper, we consider principle and theoretical performance of the saturable transformer fluxpump with a resistive commutation method. The analysis shows the high pumping flux, constant rates for increasing the charging current and high efficiency.