Analysis of Discharge Based on Toroidal Field Coils of EAST

As a fusion device,the rating charge energy of toroidal field(TF) coils of EAST is about 300 MJ,so it is very important for EAST to adopt a credible quench protection system to avoid damage to TF coils.In order to satisfy the requirements of joule integral of TF coils,a suitable discharge circuit for the huge energy must be found.Consequently,we focus on some kinds of schemes for discharge and the interlocking control for switches particularly.The double discharge is also chosen to solve the difficulty of breaker being disconnected for DC and to prolong the use life for breaker,which can be achieved at a lower arc voltage compared with the single discharge.The interlocking control scheme can both improve the reliability for protection and reduce the price for project,importantly,can set an accurate delay time,at which the backup breaker can not be disconnected in case the main breaker has been disconnected.Some analysis and experiments confirm that the chosen scheme can not only ensure the safety of TF coils,but also protect TF power supply timely.The results provide some references for the superconducting charge devices and the inductance loads.