Three-phase four-leg inverter control method under imbalanced and nonlinear load condition

Abstract

The invention provides a three-phase four-leg inverter control method under an imbalanced and nonlinear load condition, comprising step I of sampling amplitude, phase position and frequency of three-phase output voltage of the three-phase four-leg inverter in real time; after decomposing, realizing the decoupling control of the three-phase four-leg inverter through conversion of abc / dqO; step two of respectively performing closed ring control on d, q, O axles by combining repeat control technology and P1 control technology, and reaching a control goal; step three of applying a three-dimensional space vector modulation technology based on abc coordinate system after the coordinate conversion of dqO / abc, realizing the triggering control of four legs of the three-phase four-leg inverter. The three-phase four-leg inverter control method solves the problems of dissymmetry and wave distortion of three-phase output voltage of the inverter caused by imbalanced and nonlinear load in a power distribution network, and realizes the symmetrical output of the three-phase output voltage of the three-phase four-leg inverter under the imbalanced and nonlinear load condition while effectively inhibits the direct current component and resonate wave component therein.

Description

technical field [0001] The invention relates to the technical field of power transmission and distribution, in particular to a control method for a three-phase four-leg inverter under unbalanced and nonlinear load conditions. Background technique [0002] In recent years, my country has vigorously developed distributed power generation, including new energy, to meet the needs of global economic development and the dilemma of increasing energy scarcity. At present, in the power system, the inverter has become an indispensable part of the power system. As the core component of the energy conversion and control process of the distributed power generation system, it affects and determines the stability, safety, reliability and reliability of the entire system. Efficiency, and even service life and cost, have become the key to the development and application of distributed generation. [0003] But at the same time, there are a large number of unbalanced and nonlinear loads on th...

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Problems solved by technology

[0004] The purpose of the present invention is to propose a three-phase four-leg inverter control method under unbalanced and nonlinear load conditions to solve the asymmetry of the three-phase output voltage of the inverter caused by unbalanced and nonlinear loads in the distribution network , Waveform distortion problem, realize the symmetrical output of the three-phase output voltage of the three-phase four-leg inverter under unbalanced and nonlinear load conditions, and effectively suppress the DC component and harmonic component in it

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