STEADY-STATE ANALYSIS OF THE CONSTANT-FREQUENCY CLAMPED SERIES RESONANT CONVERTER

A constant-frequency diode-clamped series resonant converter (CFCSRC) is proposed as a solution to problems associated with frequency-contro lled resonant converters. This converter has two resonant frequencies, and control is achieved by varying the relative time spent at each sw itching frequency. Two zero-current-switching (ZCS) modes are examined and plotted in the output plane. An equation is given for the boundar y between the two ZCS modes, as well as an expression for the boundary between ZCS and non-ZCS operation; both are plotted in the output pla ne. The output equation for the main mode is shown to be hyperbolic. C onverter peak voltages limited to the input voltages, and peak current s are less than those of the frequency-controlled clamped series reson ant converter over a large operating range. Data from a prototype conv erter are compared with theoretical data and are shown to be in good a greement with the theoretical model.