Square against sine-the future of high frequency power conversion

Various types of sine-wave resonant and quasi-resonant high-frequency converter topologies have been studied by the power supply department of Siemens´ public switching division. Prototypes have been tested and results compared. Special attention has been devoted to practical problems such as physical limits of components, tolerances, life utility, and manufacturing process, taking into consideration the specific power supply requirements of the public switching areas. A summary of the results is provided. The limits of conventional square-wave forward converters, e.g., switching losses and control principles, are analyzed. Techniques for the improvement of high-frequency behavior are presented