A Microgrid Harmonic Suppression Method Based on Interval Optimization Algorithm

Abstract

The present invention relates to a micro-grid harmonic suppression method based on an interval optimization algorithm, and its technical characteristics are as follows: step 1, constructing a micro-grid harmonic suppression optimization model based on an interval optimization algorithm and its constraint conditions; its objective function is the harmonic voltage distortion rate of the microgrid access point; step 2, using the optimization objective function combined with the equation constraints to solve the value of the microgrid harmonic suppression optimization model based on the interval optimization algorithm in step 1; and using The branch and bound method solves the filter parameter configuration of LC when the harmonic voltage distortion rate of the microgrid access point is the smallest. The invention has the advantages of stable convergence and high calculation precision, can stably converge to the global optimal solution, and can be applied to the configuration of LC filter parameters for harmonic suppression of microgrids.

Description

technical field [0001] The invention belongs to the technical field of low-voltage power supply, and relates to a method for suppressing harmonics in a microgrid, in particular to a method for suppressing harmonics in a microgrid based on an interval optimization algorithm. Background technique [0002] There are a large number of distributed power sources in the micro-grid, and the distributed power sources mostly use power electronic converters to connect to the micro-grid. The frequent switching of switching devices will generate harmonic components near the switching frequency. The amplitude and order of the harmonics are affected by the converter. Harmonic pollution will inevitably be introduced during its operation, which will cause distortion of microgrid current and voltage waveforms. In addition, if the microgrid is directly connected to the power grid without using an isolation transformer, DC may be injected into the power grid, and the transformer and electromagn...

AI Technical Summary

Problems solved by technology

[0002] There are a large number of distributed power sources in the micro-grid, and the distributed power sources mostly use power electronic converters to connect to the micro-grid. The frequent switching of switching devices will generate harmonic components near the switching frequency. The amplitude and order of the harmonics are affected by the converter. Harmonic pollution will inevitably be introduced during its operation, which will cause distortion of microgrid current and voltage waveforms

In addition, if the microgrid is directly connected to the grid without using an isolation transformer, DC may be injected into the grid, and the transformer and electromagnetic components may experience magnetic saturation, causing torque ripples in nearby mechanical loads.

Distributed power supply and nonlinear load will also bring certain harmonic problems

[0003] Unbalanced three-phase voltage will lead to an increase in harmonic and negative sequence voltage components, causing vibration and overheating of motors and compressor loads such as refrigerators and air conditioners, as well as transformers, shortening insulation life, and increasing power loss; seriously causing voltage to be too high or too low, Some electrical equipment (such as computers) cannot work normally; in addition, the unbalanced current of the neutral line is too large, which may easily cause some relay protection devices to malfunction and cause large-scale power outages

Among them, the conventional algorithm has fast convergence speed and high reliability, but it has great limitations for discontinuous optimization problems; the artificial intelligence optimization algorithm has high global convergence for discontinuous optimization problems, but due to the limitations of the algorithm itself, It is easy to converge to the local optimal solution, thus missing the global optimal solution

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