A control method for a ten-switch clamp type three-phase non-isolated photovoltaic inverter

Abstract

The invention relates to a control method of a ten-switch clamp type three-phase non-isolated photovoltaic inverter, which divides the working modes of the ten-switch clamp type three-phase non-isolated photovoltaic inverter into six normal working modes and two freewheeling modes, and then the three sinusoidal modulation waves and the triangular wave are respectively passed through the comparator to obtain the preprocessing signal, and the preprocessing signal is processed to obtain the signal V x , V y and V t , then on the signal V x , V y , V t After processing, the grid-source control signals of ten switching tubes are finally obtained. The advantage of the present invention is that the common mode leakage can be suppressed by controlling the conduction or shutdown of the six bridge arm switch tubes, the two clamp switch tubes and the two DC switch tubes in the ten-switch clamp type three-phase non-isolated photovoltaic inverter. current, solve the problems of large common-mode leakage current and low conversion efficiency of three-phase non-isolated photovoltaic inverters, ensure the safety of people and equipment during use, and give full play to the characteristics of ten-switch clamped three-phase non-isolated photovoltaic inverters , has good practical application value.

Description

technical field [0001] The invention relates to a control method of a ten-switch clamp type three-phase non-isolated photovoltaic inverter, belonging to the technical field of power electronic DC-AC conversion. Background technique [0002] As the capacity of photovoltaic systems continues to increase, the requirements for cost, efficiency and reliability of inverters are also getting higher and higher. Photovoltaic grid-connected inverters require high efficiency, low cost, and can withstand the adverse effects of large output voltage fluctuations of photovoltaic cells, and their AC output must also meet high power quality. [0003] According to whether the inverter has an isolation transformer, it can be divided into two types: isolation type and non-isolation type. The isolated photovoltaic inverter realizes the electrical isolation of the power grid and the battery panel, ensuring the safety of people and equipment, but it is bulky, expensive, and the system conversion ...

AI Technical Summary

Problems solved by technology

In this common-mode resonant circuit, the changing common-mode voltage on the parasitic capacitance will generate a corresponding common-mode current. Due to the existence of the capacitance of the battery board to the ground, the common-mode leakage current will be generated when the inverter is working, which will increase the electromagnetic interference of the system. , affecting the quality of incoming current, endangering personal and equipment safety

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