AC/DC converters for the ITER Poloidal Field system

AC/DC converters will provide the power necessary to generate the Poloidal Field (PF) scenario and to control the plasma shape and position. Moreover, in order to provide additional voltage during the plasma initiation phase, Booster Converter and Switching Networks are used. About 2.6 GVA is the total installed power presently foreseen for the main AC/DC converters. Capability to supply 650 MW, 500 MV Ar are the site assumptions. Starting from the reference scenario, the requirements and the design criteria for the present AC/DC converter system are presented. Then, studies to optimize the design are discussed. Finally the ratings and the main characteristics of the present basic units are described.