Bifurcations in load resonant DC-DC converters

The paper demonstrates, both numerically and experimentally, the quasiperiodic and subharmonic operation in a load resonant DC-DC converter. The output voltage of the converter is controlled by a closed loop, applying constant-frequency pulse width modulation. The complexity of the system is contributed by fact that the state space is five-dimensional, with four switching surfaces dividing it into 9 subsystems. A method is developed to perform the stability analysis and to investigate the bifurcation sequences following the first instability in such a complex switching system.