Application of the energetic model of ferromagnetic hysteresis to bidirectional DC-to-DC converters with high input to output voltage ratio

The use of tapped inductors and current bi-directional switches in the classical boost or buck-boost converter leads to a high step-up ratio, thus avoiding the extreme duty cycles of the active switches and the high voltage stress of the switches. A high voltage DC-link and a battery of low voltage can therefore be coupled easily. Due to the possibility of bidirectional powerflow charging and discharging of the battery is possible. Two converters are presented and analyzed. Due to the simultaneous regulation of the switching frequency and the duty cycle on one hand and the winding ratio of an autotransformer on the other, high conversion rates of 1:6 can easily be realized. The dimensioning of the converters, their dynamical behavior, and the component stresses are analyzed. The energetic model of ferromagnetic hysteresis calculates the magnetic state of ferromagnetic materials and allows a rapid and qualitatively accurate prediction of the magnetic behavior.