A half-period modulation method for dual-boost inverters

Abstract

The invention discloses a half-cycle modulation method for a double-Boost inverter. The modulation method includes modulation of Boost 1 switching tube and modulation of Boost 2 switching tube in the double-boost inverter. The half-cycle modulation method enables the power switching tubes to work in a half-cycle high-frequency modulation state. The method includes: at an output voltage positive half cycle, the Boost 1 switching tube carries out high-frequency modulation boosting, and the Boost 2 switching tube carries out work frequency switching; and at an output voltage negative half cycle, the Boost 2 switching tube carries out high-frequency modulation boosting and the Boost 1 switching tube carries out work frequency switching. Under the same voltage gain, compared with traditional methods, the half-cycle modulation method enables the voltage and current stresses of the switching tubes to become smaller, the total switch-on times of the switching tubes to be reduced and the switch-on loss to be reduced. The inductive current ripples are reduced and inductive copper loss and iron loss are reduced and the efficiency of the double-Boost inverter is improved.

Description

technical field [0001] The invention relates to a half-period modulation method of a double Boost inverter, and belongs to the technical field of power electronic converters. Background technique [0002] Due to the influence of environmental and other factors, new energy has a wide output voltage range, which needs to be inverted into a usable stable AC voltage through a buck-boost inverter device. When the DC side voltage of the traditional inverter is lower than the output AC voltage, a boost converter needs to be added in the front stage of the inverter to achieve the boost function. But the two-stage power conversion makes the system structure complex and affects the efficiency. Boosting the voltage through a power frequency transformer has the disadvantages of heavy power frequency transformer and bulky volume. [0003] The single-stage power converter inverter is conducive to the improvement of power density and efficiency. The single-stage inverter has the advanta...

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Problems solved by technology

[0015] like Figure 7 , Figure 8 As shown, under this modulation mode, all power switches of the converter are in the high-frequency modulation state throughout the entire cycle, the inductor current is large, and the voltage and current stress of the switch tube is also large, resulting in increased inductance loss, switch on-state loss and switching loss. , is not conducive to the improvement of efficiency

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