Single-stage buck-boost dual-Boost inverter and control method thereof

Abstract

The invention discloses a single-stage buck-boost dual-Boost inverter. The inverter comprises a Boost1 boosted circuit, a Boost1 bypass switch tube, a Boost2 boosted circuit, and a Boost2 bypass switch tube. The invention further discloses a control method of the inverter. The method comprises the following steps: controlling the Boost1 boosted circuit and the bypass switch tube thereof to work to be in a boosting state in a positive half period of sine wave; controlling the Boost2 boosted circuit and the bypass switch tube to work to be in a boosting state in the negative half period of the sine wave. Under the same voltage gain, the voltage stress and the current stress of the switch tube are smaller, the total time of conducting the switch tube is reduced, the conduction loss is lowered, the inductive current ripple is lowered, and the copper loss and the iron loss of the inductance are reduced. The power frequency switching of the bypass switch tube provides loop for the current of the positive half-cycle circuit and the negative half-cycle circuit, the conduction loss of loop current in the traditional dual-Boost inverter is reduced, and the efficiency of the dual-Boost inverter is promoted.

Description

technical field [0001] The invention relates to a single-stage buck-boost double Boost inverter and a control method thereof, belonging 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...

AI Technical Summary

Problems solved by technology

In this modulation mode, all power switches of the converter are in the high-frequency modulation state during the entire power frequency cycle, and the inductor current is large, and the voltage and current stress of the switch tube is also large, resulting in increased inductance loss, switch tube on-state loss and switching loss. , at the same time, there is internal circulation in the whole converter, which is not conducive to the improvement of efficiency

Images