Harmonic analysis method for power system and device thereof

A technology of power system and harmonic analysis, applied in the direction of frequency measurement device, spectrum analysis/Fourier analysis, etc., can solve the problems of high computational complexity and insufficient calculation accuracy, and achieve the effect of simple calculation and satisfying needs

CN101852826BInactive Publication Date: 2012-09-05SIEMENS AG
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2012-09-05
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a harmonic analysis method for a power system. The method comprises the following steps: calculating fundamental frequency of the power system and windowing and performing Fourier transform on a sampled signal sequence of the power system; taking the calculated fundamental frequency of the power system as an actual frequency of the power system so as to obtain an approximate formula for windowed Fourier transform spectrum; calculating the frequency of the harmonic wave of the power system according to the calculated fundamental frequency of the power system and calculating the amplitudes of the fundamental frequency and the harmonic wave of the power system according to the approximate formula; and calculating the phases of the fundamental frequency and the harmonic wave of the power system according to the frequency difference between the frequency of the sampled signal of the power system and the frequency of the power system. The method can calculate the harmonic wave of the power system with an extremely high accuracy; and meanwhile, the method has simple calculation and meets the requirements for real-time detection of the power system.
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Description

technical field

[0001] The invention relates to a harmonic analysis method and a device thereof, in particular to a method for performing harmonic analysis in a power system and a device for realizing the method. Background technique

[0002] For real-time power monitoring equipment, it is necessary to use a high-precision, simple-calculation power harmonic analysis method to analyze the signals of the power system in real time, so as to facilitate the monitoring and adjustment of the equipment. At present, Fast Fourier Transform (FFT, Fast Fourier Transform) is widely used to calculate the harmonic frequency, amplitude and phase angle of the measurement signal in the power system. However, a disadvantage of this method is that it is difficult to realize synchronous sampling of the signal, which leads to spectrum leakage and inaccurate calculation data.

[0003] In the prior art, two methods are generally adopted to reduce the impact of spectrum leakage. One method is to s...

Examples

Embodiment Construction

[0072] figure 2 A flowchart of a method for analyzing harmonics of a power system according to the present invention is shown. The method is specifically described below by taking 6 signal sampling periods as a column.

[0073] Step 1: Calculate the frequency of the fundamental wave of the power system, and perform window processing and Fourier transform on the sampling signal sequence of the power system to obtain the amplitude and initial phase of the fundamental wave and the amplitude and initial phase of each harmonic . image 3 A flow chart of the method for calculating the frequency of the fundamental wave of the power system in the method for analyzing the harmonics of the power system in the present invention is given. Include the following steps in this step:

[0074] First, obtain the voltage signal in 6 signal sampling periods.

[0075] Second, the initial calculation of the frequency of the fundamental wave of the power system is performed based on the calcula...