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13-kV Rectifiers: Studies on Diodes and Asymmetric Thyristors

For rectifiers with high blocking voltages, the application of field stop layers reduces power losses. Preliminary experimental results are presented from asymmetric 13-kV thyristor samples based on a conventional field stop concept. By connecting a 13-kV diode in series to this asymmetric thyristor, a symmetrically blocking tandem device can be built. Numerical studies show that the turn-off behavior of the 13- kV diode required for the tandem solution can be significantly improved by a new field stop concept based on an n layer buried in the weakly-doped region of the p + -n - -n + power diode. The main objectives of development in high-power thyristor converters are the reduction of fabrication costs and greater reliability. A promising way to achieve this is to increase the blocking voltage of the thyristors so that the number of thyristors connected in series can be reduced. For high blocking voltages, a series connection of an asymmetric thyristor and a diode has lower power losses than a symmetrically blocking thyristor.

• 291.97 KB
• 2014/02/11