Small signal modelling of a half bridge converter with an active input current shaper

For some years, many authors have been writing about the use of single stage solutions to meet IEC 1000-3-2 regulations. This kind of topology can reduce the harmonic content without penalizing excessively the efficiency of the converter. Furthermore, although they are called single stage topologies, actually they are not exactly single stage converters because a part of the energy is processed twice. As a consequence, the small signal model is not evident at all because the energy flow in the converter is quite complex. This paper deals with the dynamic model of a half bridge converter with an active input current shaper. A small signal model has been obtained and the results were compared with those of a real prototype. The experimental results of the dynamic behavior are also presented.