Control method for actively suppressing power grid harmonics

Abstract

The invention provides a control method for actively suppressing power grid harmonics. A harmonic component can be precisely detected and separated by adopting a harmonic current detection method based on transient reactive power; in order to achieve a better output current control effect than the conventional proportion and integration (PI) control effect, a composite control strategy, in which fuzzy PI closed loop adjustment is taken as a core, is determined; therefore, online adjustment and optimization of PI parameters are realized; and the harmonics of a harmonic load and a device to a power grid are suppressed effectively.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a control method for actively suppressing harmonics in a power grid. Background technique [0002] With the widespread application of distributed power generation systems, its grid-connection issues have attracted more and more attention, and the harmonics and reactive power problems caused by power equipment and systems have become more and more troublesome to the grid. In practice, due to the widespread use of power electronic equipment, a large number of harmonics are generated in the power grid, and harmonic currents are very harmful to electrical equipment, which will cause serious deterioration of power quality, and have a negative impact on various electrical equipment and relay protection devices. , Computers, measuring instruments and communication systems have adverse effects, endangering the safety and economic operation of the power system. [0003] At presen...

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Problems solved by technology

In practice, due to the widespread use of power electronic equipment, a large number of harmonics are generated in the power grid, and harmonic currents are very harmful to electrical equipment, which will cause serious deterioration of power quality, and have a negative impact on various electrical equipment and relay protection devices. , Computers, measuring instruments and communication systems have adverse effects, endangering the safety and economic operation of the power system

[0003] At present, the research on harmonic detection and suppression has never stopped, but because the harmonics of the power system are affected by factors such as nonlinearity, unbalance, randomness and complexity, it is not easy to accurately detect and suppress harmonics

Although the method of detection and compensation using RC passive filter is simple, it has low reliability and poor real-time performance for unstable power grids and variable load systems; the method of using PI controller and instantaneous reactive power and instantaneous active power theory has effectively promoted The development of active power filter technology, but due to the nonlinearity of the load and the change of the operating state, it is difficult to adjust the conventional PI parameters. Therefore, a control method for active harmonic suppression that realizes online adjustment and optimization of PI parameters is sought is very meaningful

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