Real-time Monitoring,control And Protection Of Vertical Displacement Event On EAST

Vertical instability is an intrinsic instability of elongated tokamak plasma.The dis-ruption induced by vertical instability can cause severe damage to the device,therefore it is necessary to control such an instability using vertical stabilization system.Vertical stabilization system on EAST includes passive conductor stabilization system and ac-tive coil feedback control system.The controllability of this system is closely related to the growth rate of plasma vertical instability,thus it is of great significance to mon-itor and control vertical growth rate in real-time,which also provides key parameters for disruption prediction and protection.In this paper,we firstly realize the real-time computation of vertical growth rate based on plasma rigid displacement model,then de-sign the real-time monitoring and process functions for vertical instability,and develop a new vertical growth rate control module to reduce real-time vertical growth rate.For the purpose of calculating vertical growth rate,we model the EAST control system using plasma equilibrium reconstructed by PEFIT and the effective two dimen-sional EAST vacuum vessel structure model including three dimensional effects,based on rigid plasma response model.To realize real-time computation,we make use of GPU parallel computation infrastructure,build the data interface based on reflective memory high speed Internet,realize the real-time data communication between GPU compu-tation system and EAST plasma control system(PCS),and real-time computation of vertical growth rate.The calculation results agree well with experimental results.The computation performance meets the experimental requirement of real-time monitoring and control of vertical growth rate.For the purpose of controlling vertical growth rate,based on EAST ISOFLUX/PEFIT control algorithm,we build the shape response module of vertical growth rate by ana-lyzing history experimental data,design the vertical growth rate controller,and develop such a control module in EAST PCS.In 2019 EAST campaign,we successfully de-creased vertical growth rate,and realized the close loop feedback control of vertical growth rate.For the purpose of realizing the monitoring and prediction of vertical instability,we develop such a module for vertical instability in EAST PCS,by using the important parameters,i.e.,real-time vertical growth rate,Z and Zerror,based on the fault detec-tion algorithm in EAST PCS.In 2019 EAST campaign,we successfully monitored the vertical instability,and provided a trigger signal for disruption protection of massive gas injection.