Power grid voltage supporting type modularized active power filter and control algorithm

Abstract

A power grid voltage supporting type modularized active power filter and a control algorithm are provided and belong to an active power filter and a control algorithm. The topology of the active power filter is a serial combination structure of a power grid voltage supporting portion and an active filtering portion. Each phase of the power grid and voltage support portion consists of n power grid voltage supporting module units connected in series, and each unit consists of an H-bridge circuit and a shunt capacitor; and the active filtering portion consists of m active filtering module units connected in parallel, and each unit consists of a three-phase full-bridge circuit, an AC filtering inductor and a shunt capacitor. The power grid voltage supporting portion adopts a carrier phase-shifting modulation technique to track a grid-side voltage of a common coupling point, so as to reduce voltage demands at the DC side of the active portion; and the active filtering portion adopts an improved current prediction technique to track a harmonic current, so as to be adapted to the power grid voltage supporting structure. The algorithm has the advantages of low costs, high reliability, strong universality, and easy extension, and can be widely used in harmonic treatments in high voltage and high power occasions such as petroleum mining and precision manufacturing and tiny weak power grids.

Description

technical field [0001] The invention relates to an active power filter and a control algorithm, in particular to a grid voltage support type modular active power filter and a control algorithm. Background technique [0002] Since the 20th century, non-linear industrial loads such as electric boosting heating equipment, rolling mills, and welding machines have been used extensively, injecting a large amount of reactive power and harmonics into the power grid, endangering the stability of the power grid and the safety of high-precision equipment. Traditional LC tuned passive compensation devices are widely used because of their low cost and large capacity. However, its fixed impedance can only be adjusted in steps for power quality problems, so it is gradually replaced by active power filters. [0003] The shunt active power filter has the ability of flexible harmonic suppression, reactive power compensation and coupling point voltage regulation, so it is widely used to contr...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a power grid voltage support type modular active power filter and a control algorithm that meet high voltage, large capacity, and high reliability compensation, and solve the problem of expanding the capacity of traditional modular active power filters when the weak power grid is running Capacity-limited issues

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