Control method of hybrid four-leg shunt active power filter

Abstract

The invention relates to a control method of a hybrid four-leg shunt active power filter. In the method provided by the invention, a space vector control method is utilized as a core for calculation to obtain the base quantity of the output voltage reference value of legs, and a current hysteresis control method is utilized as a core for calculation to obtain the regulating quantity of the outputvoltage reference value of the legs. When the error of the reference current of the legs of the active power filter and the actual output current is smaller, the current hysteresis control is of no avail, and the active power filter is ensured to have higher control accuracy when the load harmonic content is small; when the error is larger, the regulating quantity obtained by calculation adds thebase quantity, and the active power filter is ensured to have quicker response speed when the load harmonic content is large. By utilizing the method, the adaptive ability of the four-leg active power filter can be improved, and the four-leg active power filter is ensured to well compensate the harmonic current and neutral current in the system under different harmonic conditions.

Description

A Composite Four-arm Parallel Active Power Filter Control Method technical field The invention relates to the technical field of active power filters, in particular to a compound four-arm parallel active power filter control method. Background technique Four-leg shunt active power filters are widely used to solve the increasingly serious problems of harmonics and excessive neutral current in three-phase four-wire power systems. With the continuous increase of nonlinear load applications, new characteristics of harmonics and neutral currents in three-phase four-wire power systems appear: in different seasons, different months, different working days, and even in different periods of the same working day, The harmonic characteristics vary greatly. Therefore, the new requirement for the active power filter is that it can well compensate the harmonics and neutral current when the load harmonic content is large, that is, it has fast response; when the load harmonic content is ...

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Problems solved by technology

However, due to the inevitable lag in the calculation of the reference value and the change of the current, both of these two control methods have the problem of insufficient response speed when the harmonic content is large

In order to solve the contradiction that the above-mentioned conventional switch control strategy cannot take into account the response speed requirements at high harmonic content and the control accuracy requirements at low harmonic content, some researches have proposed solutions based on prediction technology and artificial intelligence technology, etc., but there are The disadvantage of implementing complexity and not being widely adopted

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