Power supply for a three-phase plasma heating unit

摘要

A power supply for a three-phase plasma heating unit includes a three-phase transformer having a primary winding group with taps which are switched under load. The transformer also has secondary winding groups which are offset by a 60 DEG phase angle, the secondary winding groups being connected to the three-phase plasma heating unit. Converter units are also connected to the secondary winding groups. Each converter unit includes a three-phase thyristor bridge and a choke connected to the bridge. Another embodiment employs two three-phase transformers. The first transformer has a secondary winding group with taps which are switched under load. The second transformer has a primary winding group which is connected to the secondary winding group of the first transformer. The second transformer also has secondary winding groups which are offset by a 60 DEG phase angle, the secondary winding groups being connected to the three-phase plasma heating unit. Converter units, each including a three-phase thyristor bridge and a choke, are connected to the secondary winding groups.