| Abstract |
In the present state of development of GTO thyristor technology the series connection of these semiconductors is unavoidable when a high voltage convertor, in our case a 4000V chopper, is aimed. Two large GTOs (4,5 kv - 2,5 kv) are series connected in the experimental chopper. The RMS value of chopper current is 800 A. The paper will consider the criterions for the selection of GTOs, design of snubbers and adeptation of GTOs control signals. The advantages and drawbacks of the used strategie will be discussed. The detailed experimental results concerning the influence of different parameters such as load current on the transient and steady state voltage distribution on the GTOs will accomplish the paper. These results make us believe that a 5 kv chopper is conceivable from now on. As this chopper is supposed to be used in rail traction, some industrial realizations are given at the end. |
