A ten-switch interleaved clamp three-phase photovoltaic inverter topology

Abstract

The invention discloses a main circuit topology of a ten-switch interleaved clamp three-phase photovoltaic inverter. This topology first adds positive and negative busbar switches on the basis of the traditional three-phase bridge inverter to realize the disconnection of the photovoltaic panel and the output side of the inverter during the freewheeling phase; secondly, the DC input of the inverter 3 clamping capacitors are introduced on the side, so that the input voltage is divided into four potential points of 0, 1 / 3, 2 / 3 and 1; finally, two clamping switches are added alternately at the 1 / 3 and 2 / 3 potential points to make the reverse The common-mode voltage of the converter can be clamped at 1 / 3 or 2 / 3 of the output voltage of the photovoltaic panel during freewheeling, which reduces the amplitude of the common-mode voltage and makes the frequency of the common-mode voltage three times that of the triangular carrier frequency, improving The loop impedance is reduced, thereby suppressing the common-mode leakage current of the photovoltaic inverter and ensuring the safety of personnel and equipment during use.

Description

technical field [0001] The invention relates to a main circuit topology of a three-phase photovoltaic inverter, especially a main circuit topology of a ten-switch interleaved clamp three-phase photovoltaic inverter, which is suitable for high requirements on conversion efficiency and safety of personal equipment The photovoltaic power generation occasions belong to the category of power electronics DC-AC conversion. Background technique [0002] Photovoltaic inverters require high conversion efficiency, low cost, and high safety performance, can withstand the impact of large fluctuations in the output voltage of photovoltaic cells, and must also meet high output power quality. Photovoltaic inverters are generally divided into isolated and non-isolated types. The isolated photovoltaic inverter realizes the electrical isolation of the battery panel and the grid, suppresses the leakage current, and ensures the safety of the person and equipment during use, but there are always...

AI Technical Summary

Problems solved by technology

The isolated photovoltaic inverter realizes the electrical isolation of the battery panel and the grid, suppresses the leakage current, and ensures the safety of the person and equipment during use, but there are always problems such as large size, high cost, and low efficiency.

However, due to the removal of the transformer, there is an electrical connection between the input and the output, and the presence of the capacitance of the solar panel to the ground, the photovoltaic inverter will generate a common-mode leakage current during operation.

The existence of leakage current will increase the harmonic content of output current and increase electromagnetic interference, thereby reducing power quality, causing grid distortion, causing power loss, and leakage current will also affect personal and equipment safety

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