Study of electromagnetic interference on quench detecting system of HTS current leads for EAST

• EAST HTS superconducting magnet system shall be operating in a very noisy environment.
• Voltage taps will have a lot of inductive voltage induced on them which makes quench detection very difficult.
• The noise comes from the coupling between rapid pulsed poloidal coils, and radiation coupling interference associated with EAST heating systems;.
• A series of related electromagnetic compatibility simulation tests have been carried out.
• Electromagnetic noises are well restrained by choosing proper anti-interference means.

High temperature superconducting (HTS) material B-2223/Ag-Au has been used for EAST poloidal field (PF) coil current leads for reducing construction and operation cost of cryogenic system. The quench propagation velocity of HTS superconducting material is several orders of magnitude lower than that of normal low temperature current leads. It is difficult to detect weak signal of quench which is easily influenced by strong electromagnetic interference (EMI). In this paper, the sources of EMI from quench detecting system of high temperature current leads have been introduced. And we have chosen reasonable methods for good transformation and protection on the basis of electromagnetic compatibility simulation diagnosis experiments. Recent experimental results showed that the restraint of EMI has been achieved and has met the requirements of experiment.