New voltage mode control method for the quasi-Z-source-based isolated DC/DC converters

A new voltage mode control method for the quasi-Z-source isolated DC/DC converter is proposed and analyzed. Conventional control methods for Z-source or quasi-Z-source converters are based on the DC-link voltage regulation, which indirectly also influences the output. The proposed control method measures the output voltage directly and therefore better response to load changes can be expected. Small-signal AC models of the converter are derived and appropriate transfer functions found. Benefits and drawbacks of the proposed control method are analyzed on the basis of mathematical and simulation models. Simulation results are verified with experimental results. Tests were carried out on a 2 kW experimental prototype.