The AC/DC conversion system of RFX fusion experiment: operational experience and control optimization

During the operation of the high power AC/DC conversion system of RFX, a fusion experiment, instabilities and anomalous behaviours were observed when fast response is required; the more critical conditions are related with the parallel operation of power converters. To derive criteria for control optimization, the converters feeding the RFX load have been analyzed, both analytically and with computer simulation. The paper reports, after a brief converter system description, the more interesting mis-operations and the results of the control analyses