Dynamic modeling and controller design of flyback converter

The accurate dynamic modeling and quantitative controller design for an iso lated converter with optocoupler isolation in its feedback loop are conside red to be difficult issues, since the transfer characteristics of some bloc ks are highly nonlinear and difficult to be modeled analytically, First a c urrent-mode controlled flyback converter with an optically isolated feedbac k path is designed. Then the equivalent control system block diagram is con structed, and its block transfer functions are found, To increase the accur acy, the dynamic models of some critical blocks are estimated from measurem ents. In order to facilitate: the controller design, the model simplificati on is further made. Finally, based on the. reduced dynamic model, a quantit ative:; design procedure is derived to find the parameters of the voltage c ontroller to meet the prescribed regulating specifications. Validity of the estimated dynamic model and the proposed controller design approach is dem onstrated by some simulation and experimental results.