Inter-harmonic wave detection instrument based on DSP and detection method thereof

Abstract

The invention relates to an inter-harmonic wave detection instrument based on a DSP (Digital Signal Processor) and a detection method of the inter-harmonic wave detection instrument. According to the structure of the inter-harmonic wave detection instrument, three-phase voltage and three-phase current are respectively connected with a filter circuit through a voltage transformer and a current transformer; the output end of the filter circuit is respectively connected with an over-zero comparator circuit and an A / D (Analog / Digital) sampling circuit; the output end of the over-zero comparator circuit is connected with a phase selection switch-on circuit; the output end of the phase selection switch-on circuit is connected with a phase locking frequency multiplier circuit; the output end of the phase locking frequency multiplier circuit is connected with the A / D sampling circuit; the output end of the phase locking frequency multiplier circuit is connected with a DSP chip. The inter-harmonic wave detection instrument can test inter-harmonic wave of a power grid, is precise and rapid in testing, can achieve an expected target, and functions as preventing equipment from damage caused by the inter-harmonic wave, and a reference is provided for processing on the inter-harmonic wave.

Description

technical field [0001] The invention relates to a power system detection instrument, in particular to a DSP-based inter-harmonic detection instrument and a detection method thereof, belonging to the technical field of intelligent substations. Background technique [0002] With the widespread use of nonlinear components such as power electronic devices in the power grid, in addition to the harmonics of integer multiples of the fundamental frequency, the power grid may also generate interharmonics of non-integer multiples of the fundamental frequency, such as 1 / 2, 1 / 3, 1 / 4 power frequency harmonics. Interharmonics will bring some new problems to the grid, such as subsynchronous oscillation, voltage fluctuation and flicker. [0003] Inter-harmonics can cause overheating and reduced service life of electrical equipment; cause filter resonance, overload, and communication interference; can also cause malfunction of digital relays that work at zero crossing; inter-harmonics can c...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problems existing in the above-mentioned prior art, and provides a DSP-based inter-harmonic detection instrument, which uses HHT (Hilbert-Huang Transform, HHT) transformation for inter-harmonic detection, and solves the problems that cannot be solved in the prior art. The Problem of Extracting Interharmonic Signals of Arbitrary Frequency

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