Hybrid GTO Cycloconverter

Abstract

This paper describes the hybrid cycloconverter in which a self-commutated converter is connected with a line-commutated converter in antiparallel. The conventional cycloconverter has disadvantage of low power factor in power source. However, the hybrid one can achieve unity of displacement factor. The principle of the hybrid cycloconverter is the following:
When the phase control angle for a self-commutated converter is controlled on the condition of leading phase, the input power alternately repeats lagging and leading corresponding to the polarity of the output current. In the case of polyphase output, lagging and leading reactive power are canceled each other in power source, and displacement factor becomes unity.
Moreover, the output current in hybrid one is continuous with no circulating current. Experiment results obtained from hybrid GTO cycloconverter, in which GTOs are applied to self-turn-off devices, are shown to confirm the theory.