Three-phase grid-connected inverter system based on double resonant filter

Abstract

The invention discloses a dual-resonance-filter based three-phase grid-connected inverter system, and solves the problems of high power consumption and unobvious filtering effect on high-frequency harmonics existing in the current grid-connected inversion filtering system. According to the dual-resonance-filter based three-phase grid-connected inverter system, the output end of a direct current power supply (1) is connected with the input end of a three-phase inverter (2); the output end of the three-phase inverter (2) is connected with a three-phase alternating current power grid (3) through the dual-resonance filter (4); the inverter side inductor of the three-phase dual-resonance filter (4) is connected with the output end of the single-phase inverter (2); the grid-side inductor of the three-phase dual-resonance filter (4) is connected with a single-phase alternating current power grid (3); and two groups of three-phase resonant branches which are connected in a start connection method are arranged on the connecting points of the inverter side inductor and the grid-side inductor of the three-phase dual-resonance filter (4). Harmonic pollution to the power grid when the distributed power supply is connected to the power grid is effectively reduced.

Description

technical field [0001] The invention relates to a grid-connected inverter system used when solar power generation is connected to the existing AC power grid, in particular to a grid-connected inverter system that can effectively filter out high-frequency switching harmonics generated by a three-phase grid-connected inverter Grid-connected inverter system. Background technique [0002] When the distributed DC power supply is connected to the existing three-phase grid, the three-phase grid-connected inverter is the main interface for connecting the distributed power supply to the grid and is an indispensable component. The three-phase grid-connected inverter converts direct current into three-phase alternating current through pulse width modulation. When the three-phase grid-connected inverter completes the pulse width modulation process, it will inevitably generate high-frequency switching harmonics of different frequencies. Severe high frequency harmonic pollution. High-f...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a three-phase grid-connected inverter system based on a double-resonant filter, which solves the technical problems of large active power loss and insignificant improvement of high-frequency harmonic filtering effect in the existing grid-connected inverter filter system

Images