Upgrade of converter unit of EAST poloidal field power supply

Two converter units of EAST poloidal coil power supply have been upgraded last year. It is now rated at 1100 V in no-load voltage and ±15 kA in DC current. The topology has been changed to back to back bridge from same-phase antiparallel connection and a compact-PCI bus based local controller has been employed to meet the real-time requirement of 1 ms control cycle. In this paper, first, the design, analysis and simulation on this converter system are introduced. Then, details of the converter module, controller, monitoring and data acquirement are presented. Lastly, the test result of current and voltage during EAST 2010 autumn campaign is introduced. The result shows that the design meets the requirement.