Micro-grid harmonic suppression method based on synchronous inversion technology

Abstract

The invention discloses a micro-grid harmonic suppression method based on a synchronous inversion technology. Firstly, according to a voltage output model of a micro-source inverter in a micro-grid, a harmonic suppression method is researched by analyzing a harmonic generation reason and a voltage quality deterioration mechanism in the micro-grid in an isolated island operation state; secondly, according to the reason and mechanism of harmonic generation, the harmonic is suppressed by adopting a control strategy of combining a synchronous inverter and frequency division suppression, and the relationship between each system parameter of the synchronous inverter and active power P and reactive power Q is obtained by analyzing the mathematical model of the synchronous generator; a synchronous inverter control module with frequency and voltage control and active and reactive power regulation is designed; according to voltage information of a system, after d-q conversion and a low-pass filter, harmonic components of different frequencies of system voltage are extracted, and a harmonic frequency division suppression control module is designed based on a harmonic frequency division suppression algorithm.

Description

technical field [0001] The invention is suitable for harmonic suppression of micro-grid, is a harmonic suppression method based on synchronous inverter technology, and belongs to the technical field of inverter control. Background technique [0002] At present, the micro-grid control method is mainly to control the grid-side voltage and current of the micro-source in the micro-grid by controlling the inverter. Compared with the traditional power grid that mostly uses synchronous generators as power sources, the micro-source in the micro-grid lacks inertia. And damping, considering that a large number of distributed power sources are connected to the microgrid, it will have a negative impact on it to a certain extent. Moreover, when the microgrid operates in an island, since there is no support from the external grid, the internal fully-controlled power electronic inverter and the nonlinear load on the load side will cause a large number of harmonics in the microgrid, which w...

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Problems solved by technology

[0002] At present, the micro-grid control method is mainly to control the grid-side voltage and current of the micro-source in the micro-grid by controlling the inverter. Compared with the traditional power grid that mostly uses synchronous generators as power sources, the micro-source in the micro-grid lacks inertia. and damping, considering that a large number of distributed power sources are connected to the microgrid, it will have a negative impact on it to a certain extent

Moreover, when the microgrid operates in an island, since there is no support from the external grid, the internal fully-controlled power electronic inverter and the nonlinear load on the load side will cause a large number of harmonics in the microgrid, which will affect the voltage of the microgrid. The quality has a serious impact and cannot meet the needs of users with high requirements on power quality

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