Modeling, analysis and simulation of "AC inductor" based converters

The operation of converters that include power inductors with no DC current - defined here as "AC inductors" - was studied analytically, by simulation and experimentally. A SPICE compatible model was developed and the simulation results for small and large signal response were verified against theoretical and experimental results. The behavior of the "AC inductor" based converters, as revealed in this study was compared to conventional PWM converter in which the power inductor is exposed to DC current ("DC inductor"). Based on the results of this study one can conclude that "AC inductor" based topologies are optimal for current sourcing applications, such as battery chargers, where differences between the average input and output voltages are expected to exist and develop over time. The advantage of these topologies in DC-DC converters, from the dynamics point of view, is that the control small signal transfer function (frequency perturbation to output voltage) is of first order for the practical bandwidth of operation.