Inverter input-stage circuit with wide voltage input range and inverter

Abstract

The invention is suitable for the field of electric energy conversion and provides an inverter input-stage circuit with a wide voltage input range and an inverter. The inverter input-stage circuit comprises a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, a first bypass switch K1, a second bypass switch K2, a mode selection switch K3, an inductor L and a sampling control module; when the input voltage value is too high, the first switching tube Q1, the second switching tube Q2 and the inductor L form a step-down circuit which is used for reducing the output voltage value; and when the input voltage value is too low, the second switching tube Q2, the third switching tube Q3 and the inductor L form a booster circuit which is used for boosting the output voltage, and therefore a wider voltage input range is achieved. In addition, the voltage at the output end of the inverter input-stage circuit is stable, the DC busbar voltage level of the inverter input-stage circuit can be reduced, the life of a DC busbar support capacitor of the inverter input-stage circuit is prolonged and the cost is reduced.

Description

technical field [0001] The invention belongs to the field of electric energy conversion, and in particular relates to an inverter input stage circuit and an inverter with a wide voltage input range. Background technique [0002] An inverter is a conversion device that converts direct current into alternating current. The grid-connected inverter refers to an inverter that converts the DC power generated by renewable energy into an AC power with the same frequency and phase as the mains that can be connected to the mains. The grid-connected inverter generally includes Photovoltaic grid-connected inverters, wind energy grid-connected inverters, fuel cell grid-connected inverters, etc. [0003] In many grid-connected inverters, such as photovoltaic grid-connected inverters, the output characteristics of solar cells will change with changes in external environmental conditions. At night, the output voltage of solar cells is close to 0, and the corresponding voltage value of the ...

AI Technical Summary

Problems solved by technology

However, the step-down circuit has a narrow input voltage range, and it still cannot meet the working requirements of the inverter for low-voltage input.

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