Parallel connection hybrid type active power filter and control method thereof

Abstract

The invention discloses a parallel connection hybrid type active power filter and a control method thereof. The parallel connection hybrid type active power filter comprises an inverter, an output filter, a five-time passive filter, a seven-time passive filter and a shunt inductor. The five-time passive filter and the seven-time passive filter are directly connected in a grid in parallel. The seven-time passive filter and the shunt inductor are connected in series. The inverter is connected to the middle point of the seven-time passive filter and the shunt inductor after passing through the output filter. The control method is a recursive integral PI control method based on membership clouds. A membership cloud model is used for carrying out on-line adjustment on a proportionality coefficient and an integral coefficient of a recursive integral PI controller, and the response performance of a control system is improved. The parallel connection hybrid type active power filter and the control method thereof can be used for carrying out dynamic and real-time governance on each subharmonic current and reactive current, and have higher cost performance and engineering practicability.

Description

technical field [0001] The invention relates to a power filter and a control method thereof, in particular to a parallel hybrid active power filter and a control method thereof. Background technique [0002] Electric energy is an indispensable and important energy source in modern society. The sustainable development of electric power has become the basis for realizing the sustainable development of society and economy, and plays an important balancing role in the coordinated development of society, economy, energy and environment. In recent years, with the increasing number of nonlinear loads such as rectifiers, frequency converters, and electrified railways in the distribution network, power quality problems such as current waveform distortion, voltage fluctuation, and three-phase imbalance have become increasingly serious. [0003] At present, the harmonic control and reactive power compensation devices that are widely used in high-voltage distribution networks such as 6k...

AI Technical Summary

Problems solved by technology

However, PPF has the following disadvantages: it can only filter out harmonics of a specific order, the filtering performance is greatly affected by the parameters of the PPF itself and the grid parameters, there is the possibility of harmonic amplification or resonance with the equivalent impedance of the system, and the load harmonic fluctuation is relatively large. When it is large, it is easy to cause filter overload, etc.

However, limited by the withstand voltage rating of switching devices, it is difficult to directly apply the pure parallel APF to the high-voltage system of the distribution network, and the cascaded and hybrid active power filters HAPF are gradually developed.

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