Determination of stable region of controller parameters for series-parallel resonant converter with capacitive output filter

This paper reports to determine the controller parameters for the stable operation of one member of a load resonant dc-dc converters by a newly developed tool. The study is confined to the series-parallel topology with capacitive output filter. The constant frequency phase shift modulation technique is employed with proportional-integral controller in the output voltage regulation. The analysis complexity is very high due to fact that nine topological modes and four switching surfaces give rise to several operation modes. In addition to the determination of the controller parameters for stable operation, different mechanisms of instability of period-1 limit cycle are predicted from the design curve which constitute an important help for any designer.