Effect factors on stray capacitances in high frequency transformers

High-frequency operation of flyback converter shows that parasitic components associated with power transformer have great influences on the behavior of the converter. Leakage inductance and stray capacitance are two major parasitic components. But stray capacitance is seldom being considered in transformer design. A relative simplified transformer model for convenience in the engineering analysis was given after comparison of existing models. Then for high input voltage and low output voltage application, effects of parasitic winding capacitance on the operations of high-voltage, high-frequency flyback converter were analyzed and the influence of the way of winding strategy on winding capacitance was studied. At last, some experimental results were given, which verified the correctness of analysis and practicability of proposed suppression method.