High power IGBT bridge application for the harmonic suppression on the load side of the power supply system of the Spanish Stellarator TJ-II

TJ-II is a medium size stellarator of the heliac-type, which is successfully in operation at CIEMAT in Madrid, since March 1998. This machine allows operation in a wide range of magnetic field configurations. This fusion device comprises seven inductively coupled coil systems, which produce the magnetic fields required for the confinement of the plasma. These coils are powered separately by 12-pulsed thyristor converters. The DC currents in the coils have a content of harmonics and sub-harmonics and these harmonics should be kept at very low level because of negative influence on the plasma confinement. The paper describes the design, calculations and tests of an active high power filter for the harmonic suppression.