Large-signal decomposition decoupling control method and device for buck-boost converter

Abstract

The invention discloses a method and device for large signal decomposition and decoupling control of a buck-boost converter. The method includes: decomposing the converter system into a disturbance part, a current loop controlled object and a voltage loop controlled object to construct a converter system Large-signal circuit model; feed-forward decoupling for the disturbance part; inverse system decoupling and linear feedback for the current loop controlled object to compensate it into a pseudo-linear system, so that the compensated current loop open-loop transfer function is a first-order pure Integral link; and performing inverse system decoupling and linear feedback on the controlled object of the voltage loop to compensate it into a pseudo-linear system, so that the compensated open-loop transfer function of the voltage loop is a unit system. The invention can separately control the disturbance part, the controlled object of the current loop and the controlled object of the voltage loop, so that the disturbance control, the dynamic characteristic control of the voltage loop and the dynamic characteristic control of the current loop of the buck-boost converter become independent of each other Independent process to achieve decoupling control.

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-boost converter. Background technique [0002] Small-signal modeling of buck-boost 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 , so that the disturbance must be much smaller than the DC operating point; (2) In actual analysis, the disturbance of the DC power supply and load is usually ignored, and it is simplified to a single-input single-output system, resulting in a large margin for the designed controller, and also The working performance of the converter under large signal disturbance and wide range operation cannot be guaranteed. [0003] With the development of new energy distributed DC power s...

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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 of a buck-boost converter, thereby overcoming the limitations of the small-signal modeling method of the buck-boost converter and the coupling relationship of the buck-boost converter. Disadvantages of very complex controller design

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