Simultaneously Solve Nonlinear Modeling Method for Multiscale State Variables of Switching Converters

Abstract

The invention discloses a nonlinear modeling method for simultaneously solving multi-scale state variables of a switching converter. According to the method, in the modeling process, a switching tubeand a diode are equivalent through mechanism models of the switching tube and the diode, a discrete switching function describing the on-off characteristics of a device is fitted through a continuousnonlinear periodic function, and a unified nonlinear continuous mathematical model describing the state variables of the circuit level and the device level of the switching converter is obtained; anda nonlinear analysis method is used for solving, so that approximate analytical expressions of steady-state periodic solutions of the state variables of the circuit level and the device level of the switching converter can be obtained at the same time, namely, a steady-state periodic analytical solution of the multi-scale state variables of the switching converter can be obtained. According to themethod, unified modeling combining the device-level scale and the circuit-level scale of the switching converter is realized, and continuous unified modeling of the converter is realized by adoptinga continuous nonlinear periodic function to fit a traditional discrete switching function for describing the on-off characteristics of the device.

Description

technical field [0001] The invention relates to the technical field of modeling and analysis of switching converters, in particular to a nonlinear modeling method for simultaneously solving multi-scale state variables of switching converters. Background technique [0002] The switching converter is a nonlinear time-varying system, and the analytical solution for its dynamic characteristics is relatively complicated. The existing nonlinear analysis methods include the state-space averaging method, the circuit averaging method, the generalized state-space averaging method and the equivalent small parameter Law and so on. Among them, the state-space averaging method only considers the approximation of the system's low-frequency characteristics, but ignores the high-frequency dynamic characteristics of the system, so it cannot be used to analyze the ripple of the converter waveform. The three-terminal switching device model method commonly used in the circuit averaging method n...

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Problems solved by technology

However, the existing modeling methods of switching converters usually only analyze the state variables at the circuit level, and ignore their dynamic characteristics for switching devices, and only use discrete switching functions to describe their on-off states, so the established mathematical models cannot Reflecting the influence of device-level state variables on circuit operation, the analysis results have little guiding significance for the actual converter parameter design

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