Large signal decomposition and decoupling control method and device of buck converter

Abstract

The invention discloses a large signal decomposition and decoupling control method and device of a buck converter. The method includes the steps that a converter system is decomposed into a disturbance part, a current loop controlled object and a voltage loop controlled object to build a large signal circuit model of the converter; the disturbance part is subjected to feed-forward decoupling; the current loop controlled object is subjected to inverse system decoupling and linear feedback to compensate the current loop controlled object as a pseudo-linear system, and a compensated current loop open-loop transfer function is a first-order pure integral link; the voltage loop controlled object is subjected to inverse system decoupling and linear feedback to compensate the voltage loop controlled object as a pseudo-linear system, and a compensated voltage loop open-loop transfer function is a unit system. According to the method and device, the disturbance part, the current loop controlled object and the voltage loop controlled object can be independently controlled, so that disturbance control, voltage loop dynamic characteristic control and current loop dynamic characteristic control of the buck converter become independent processes which are not mutually influenced, and decoupling control is achieved.

Description

technical field [0001] The invention relates to the technical field of power electronic converter control, in particular to a large-signal decomposition and decoupling control method and device for a buck converter. Background technique [0002] Small-signal modeling of buck converter and linear feedback control is a mature analysis and research method at present, but this method has the following limitations: (1) The product term of duty cycle and input voltage or state variable is ignored, thus It is required that the amount of disturbance must be much smaller than the DC operating point; (2) In actual analysis, the disturbance of DC power supply and load is usually ignored, and it is simplified to a single-input single-output system, which leads to a large margin in the designed controller and cannot guarantee The working performance of the converter under large signal disturbance and wide range operation. [0003] With the development of new energy distributed DC power ...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a large-signal decomposition and decoupling control method and device for a buck converter, so as to overcome the limitations of the small-signal modeling method of the buck converter and the very complicated design of the controller due to the coupling relationship of the buck converter shortcoming

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