Single-stage single-phase high-gain combined boost inverter circuit and boost inverter method

Abstract

The invention relates to a single-stage single-phase high-gain combined boost inverter circuit and a boost inverter method. The circuit is formed by sequentially cascading an input direct-current source, a switch inductance-capacitance network, a single-phase high-frequency combined modulation switch, an output filter circuit and an alternating-current load or a power grid load. Compared with a traditional inverter, the inverter circuit has the advantages of being high in single-stage power transmission density, small in size, small in switching loss, high in efficiency and the like, and is suitable for medium-capacity and small-capacity inversion occasions.

Description

Technical field [0001] The invention relates to the technical field of power electronic conversion, in particular to a single-stage single-phase high-gain combined boost inverter circuit and a boost inverter method. Background technique [0002] At present, in the occasion of small and medium capacity inverters, Buck-type single-stage single-phase voltage-type inverter circuit structure is often used, but this type of inverter requires the DC bus side voltage to be higher than the AC side phase voltage peak value, which is obvious Defects: (1) The input DC side voltage must be higher than the AC side phase voltage peak value; (2) As new energy sources such as photovoltaics and wind power are affected by weather and climate, the DC side voltage may be lower than the normal operating range, causing the system to fail to work. For these problems, a two-stage inverter structure is often used to add a Boost DC converter in the front stage or a single-phase power frequency transformer ...

AI Technical Summary

Problems solved by technology

[0002] At present, in small and medium-capacity inverter occasions, Buck-type single-stage single-phase voltage-type inverter circuit structure is often used, but this type of inverter requires that the voltage on the DC bus side be higher than the peak voltage on the AC side. Defects: (1) The input DC side voltage must be higher than the peak phase voltage of the AC side; (2) Due to the influence of weather and climate on new energy sources such as photovoltaic wind power, the DC side voltage may be lower than the normal operating range, resulting in the system not working

[0004] 1. The buck-type single-stage single-phase voltage-type inverter circuit structure has obvious defects: (1) the input DC side voltage must be higher than the peak value of the AC side phase voltage; Climate impact may make the DC side voltage lower than the normal operating range, causing the system to fail to work

[0005] 2. The method of adding Boost DC converter in the front stage constitutes a two-stage inverter structure or the method of adding a single-phase power frequency transformer to the output, but it will cause the system to have a complex structure, reduce system efficiency, increase volume, weight, and cost, etc. question

[0006] 3. If the Boost-type single-stage single-phase current-type inverter circuit structure with a bypass switch is used, there are problems such as limited inverter gain range and large switch tube stress.

[0007] 4. Aiming at the shortcomings of traditional inverter boosting capacity and working efficiency in the existing technology in small and medium-capacity inverter occasions, a single-stage single-phase high-gain combined boost inverter is provided

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