|Autors: Dimitrov, V. V., Goranov, P. T.|
Title: Modelling of Step-Up DC Converter
Keywords: Power electronics, Power converter modelling, small-signal model
Abstract: In the current paper building on the sound theoretical foundation of state-space methods a model for the boost converter is presented. Replacing some elements in the ideal power convertor with their nonideal equivalent circuits results in a general vector nonlinear time-varying differential equation describing the circuit behavior. Averaging the equation for one time period of the control frequency approximates the equation with one that is time-invariant. Solving the obtained equation for a particular equilibrium point results in a general expression for steady-state behavior. Subsequent small-signal linearization around the steady-state transforms the model to a linear time-invariant system (LTI). Using Laplace transform of the LTI system results in input–to-output and duty cycle-to-output transfer functions. The results for steady-state and small-signal dynamic modelling are plotted and some comments are made about optimum converter behavior.
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