Hierarchical PI transition control method and system based on Boost circuit DCM/CCM mode switching

Abstract

The invention relates to a hierarchical PI transition control method and system based on Boost circuit DCM / CCM mode switching. The method comprises the steps of carrying out PI hierarchical division according to the output voltage of a Boost circuit and PI parameters, and enabling the PI hierarchical division to comprise a seal pulse PI region, a steady-state PI region and a hierarchical PI region; further dividing the hierarchical PI region into n PI grades, wherein the n PI grades comprise a first hierarchical PI region to an nth hierarchical PI region; arranging hysteretic transition regions between the steady-state PI region and the first hierarchical PI region and between two adjacent PI regions in the hierarchical PI region; when the Boost circuit is switched from the DCM mode to theCCM mode or from the DCM mode to the CCM mode, determining the PI region to which the output voltage Uo _ i of the Boost circuit belongs at the current moment ti, and adjusting the current PI valuesof a voltage loop and a current loop to be the PI value of the PI region to which the output voltage Uo _ i of the Boost circuit belongs at the current moment. According to the method, a PI multistageswitching mode and a hysteresis control method are utilized; the oscillation problem of the system and smooth transition of output voltage when PI parameters change in a large range are solved; and continuous work of two working modes is achieved.

Description

technical field [0001] The invention belongs to the technical field of Boost chopper circuit control, in particular to a hierarchical PI transition control method and system based on Boost circuit DCM / CCM mode switching. Background technique [0002] The existing Boost converter has the advantages of simple structure and control, and is widely used in energy storage systems, electric vehicles, photovoltaic systems, rail transit and other fields. Currently, Boost circuits are mainly used in two-level and three-level circuit topologies. The topology is as follows: figure 1 as shown, figure 1 (a) is a schematic diagram of a two-level Boost circuit, figure 1 (b) Schematic diagram of the three-level Boost circuit. Similar to the Buck circuit, the working mode of the Boost converter is divided into two types: the inductor current continuous mode (CCM) and the inductor current discontinuous mode (DCM). The critical conditions of Boost circuit working mode are: 1) when When , ...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problem that the existing Boost circuit only works in DCM or CCM single mode, the present invention provides a hierarchical PI transition control method and system based on Boost circuit DCM / CCM mode switching. The method utilizes the PI hierarchical transition scheme to realize Continuous operation of two working modes, smooth transition of output voltage

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