Transformer-induced low-frequency oscillations in the series-resonant converter

The article demonstrates the existence of a number of modes of transformer-induced low-frequency oscillations (TLO´s) which can be observed in the series-resonant power converter with a transformer in the resonant circuit, operating under conditions of cyclic stability. The TLO phenomena are mathematically analyzed and the conditions of existence are determined. Experimental observations confirm the outcomes of the mathematical analyses. The critical aspects of the TLO phenomena with respect to the converter performance are explored.