Series filter and low harmonic rectifier

Abstract

The invention discloses a filter consisting of an inductor and a capacitor connected in series between a power supply and a load. The filter can filter harmonics with different frequencies. The power frequency fundamental wave impedance selection of the inductor or the capacitor is between 50 percent and 200 percent of load equivalent impedance (the load equivalent impedance is a ratio of a phase voltage effective value to a phase current effective value). A low harmonic rectifier formed by combining a series filter and a thyristor rectifier has low harmonic input current.

Description

Technical field:

[0001] The invention relates to a filter device used for filtering out harmonics in a power system and a rectifying device capable of reducing harmonic currents. Background technique:

[0002] Most of the existing harmonic filtering devices use passive parallel filters, and a set of filters is required for each harmonic frequency, and usually multiple sets of filters are required to filter out harmonics of different frequencies. The use of multiple sets of filters results in complex structure and high cost, and because the usual system contains harmonic components of infinite frequencies, it is impossible to filter out all the harmonics.

[0003] Most of the existing rectifiers use the method of increasing the number of rectification phases to reduce the harmonic content, such as using 6-phase or 12-phase rectifiers. Increasing the number of rectification phases doubles the complexity of the rectifier and increases the commutation gap, but the high-frequenc...

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