A dual-loop decoupling control method for active power filters

Abstract

The invention discloses a double-loop decoupling control method of an active power filter. The double-loop decoupling control method comprises the following steps of collecting relevant signals and converting the relevant signals into digital quantities; obtaining a reference voltage by double-loop decoupling control; and then obtaining a duty ratio signal of a switch tube according to sine pulse width modulation or space vector pulse width modulation, thereby controlling on and off of the switch tube of the active power filter. Grid synchronization and fundamental wave power control are achieved by an inner-loop controller while an outer-loop controller achieves fast and accurate tracking of a harmonic current. According to the control method, a harmonic current extraction process and a phase-locked loop can be omitted, and the calculating amount of a digital control system is greatly reduced. The double-loop decoupling control method plays an important role in reducing the system loss and ensuring safe and stable operation of the system. By the control method, the cost of the device can be reduced when the power quality is improved.

Description

technical field [0001] The invention relates to a method for an active power filter, in particular to a method for improving power quality based on decoupling double-loop control of a resonant controller. Background technique [0002] In recent years, problems such as energy shortage and environmental pollution have become increasingly serious. Therefore, the development and utilization of new energy sources such as solar energy, wind energy, and hydrogen energy are accelerating day by day, and new distributed power generation technologies are attracting more and more attention. In the distributed grid-connected power generation system, most of the electric energy generated by the energy conversion device must be converted into AC power with the same frequency and phase as the grid voltage through the grid-connected inverter before it can be fed into the grid and connected to the grid. The inverter plays an essential interface between the renewable energy conversion device ...

AI Technical Summary

Problems solved by technology

However, its dynamic response characteristics are slow and cannot quickly track harmonic current changes, thus limiting its application range

Moreover, active power filters for industrial applications require harmonic current extraction links and phase-locked loop links, so they have a heavy computational burden and high cost

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