High voltage converter for purpose to minimizing of weight of traction transformer

This paper describes the variants of realization of high voltage converter for purpose to minimizing of weight of traction transformer (so called “electronic-transformer”). The high voltage converter brings the possibility of using medium frequency transformer (with frequency for example 400Hz) instead of classical massive low frequency transformer (for trolley-line frequency 50Hz resp. 16.7Hz). This paper compares different variants of these high voltage converters - i.e. the topologies of indirect frequency converter, direct frequency converter (cycloconverters and matrix converters). Main attention is devoted to variants realized by authors (i.e. high voltage matrix converter)