Harmonic and inter-harmonic separation detecting method and device suitable for vessel electric power system

Abstract

The invention discloses a harmonic and inter-harmonic separation detecting method and device suitable for a vessel electric power system, and belongs to the technical field of vessel electrical engineering. The device comprises a voltage transducer, a current sensor, a chassis wiring terminal, a signal conditioning circuit, a data acquisition card and an industrial control computer, wherein the wiring terminal, the data acquisition card and the signal conditioning circuit are mounted inside the industrial control computer; the industrial control computer acquires input data through a standard serial port, and LabVIEW software of a virtual instrument is used for restoring collected signals according to the transformation ratio, and original signals are recorded; the comprehensive detection on parameters such as frequency, amplitude value and phase of fundamental wave, harmonic and inter-harmonic can be completed; the detection result can be directly displayed on the liquid crystal display of the industrial control computer. According to the invention, a frequency tracking algorithm, a fundamental wave and harmonic extraction algorithm and an inter-harmonic detection algorithm are adopted to implement the fundamental wave, harmonic and inter-harmonic separation detection.

Description

technical field [0001] The invention belongs to the technical field of ship electrical engineering, in particular to a method and device for detecting and detecting harmonic and interharmonic parameters. Background technique [0002] With the rapid development of power electronics technology in recent years, a large number of non-linear loads such as rectifier power supply, frequency converter, speed control converter and general frequency converter are connected to the ship power system, which makes the harmonic and The problem of interharmonics is becoming more and more serious. Since the ship's power system is an independent small-capacity power grid, the generation of harmonics and interharmonics will not only seriously reduce the power quality of the ship's power grid, but may also threaten the safe operation of the entire ship's power system. It is very urgent to analyze and study the harmonic and interharmonic problems, and to take corresponding suppression measures....

AI Technical Summary

Problems solved by technology

[0004] At present, ship power systems often use methods based on Fourier transform or instantaneous reactive power theory to detect harmonics or interharmonics. The detection method based on Fourier transform has low frequency resolution when the sampling time is limited. The detection method of instantaneous reactive power theory generally only considers the separation of fundamental wave signal, and the above two detection methods cannot realize the separation detection of fundamental wave, harmonic wave and interharmonic wave;

[0005] Both of the above two methods use a phase-locked loop structure, and the hardware implementation is complicated, and the performance of the phase-locked loop will be affected by harmonics, inter-harmonics and three-phase imbalance;

[0006] In addition, the detection method based on the instantaneous reactive power theory is mainly proposed for the three-phase AC grid, and is not applicable to the single-phase AC grid and possibly the DC grid

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