Sensitivity Analysis on a Quench Detection Method Based on Current Redistribution for Parallel Connected HTS Co-Windings

Quench problems seriously affect HTS magnets, leading to great hidden dangers on their safety operation. In our previous work, a current redistribution based quench detection method for parallel connected HTS co-windings has been proposed, which has been proved very rapid and sensitive. In this paper, influence factors on the sensitivity of this quench detection method, including the inductance and coupling tightness of the co-windings, the quench voltage, the contact resistance and current changing rate, are analyzed by analytical analysis and experiments. In conclusion, it is found that the coupling tightness determines the sensitivity of the whole system in different operations, larger quench voltage results in more obvious current redistribution phenomenon. On the other hand, fast operating current changing will result in decrease of the sensitivity since the threshold will become higher. Contact resistance will make it more difficult to detect the quench resistance. This work is beneficial for practical application of our proposed method and might be useful for more efficient quench protection on HTS magnets.