Pick-Up Coil Quench Detection Method on EAST

A timely, accurate, and reliable quench detection system is important to the safe operation of superconducting magnets. For the superconducting magnets with rapidly changing current in the fusion device, the core challenge is to compensate the complex induced voltage to obtain the quench voltage signal. The EAST device has adopted the widely used co-wound wire (CWW) method for compensation. However, the CWW has experienced several failures during operation, and its installation within the insulation layer of the superconducting magnet makes repair extremely difficult. The pick-up coil is an alternative quench detection method that is relatively easy to install and repair. In this article, a pick-up coil was designed, installed, and tested on the poloidal field 9 magnet of EAST. Experiments have shown that the pick-up coil can suppress 88% of the induced voltage. After the secondary compensation of improved Inductive Noise Realtime Calculation, the output signals meet the requirements of the quench detection system. In addition, simulated quench events during the experiments confirmed that this method can accurately detect the occurrence of a quench. Therefore, the pick-up coil can be used as a backup scheme for quench detection.