Frequency change control in a de-synchronized generator

This paper relates to the field of power electronics and in particular to power generation with high speed generators driven directly by gas or steam turbines. After reminding problematic and the interest to operate the generator at variable speed, the authors propose a structure based upon a direct matrix converter with natural commutations. This solution allows a frequency conversion in a different way than classical cycloconverters, and therefore with a larger input frequency range for a given output frequency. Nevertheless, timing constraints due to natural commutations need an accurate analysis of their influence on the frequency shift, and the means to control it.